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Re: Solar charging for MTR.

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  • jgaffke
    ... If it was MPPT, that would be the lead story. In big print. With the usual overly optimistic best case efficiency figures. MPPT really starts making
    Message 1 of 30 , Mar 25 9:57 AM
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      --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
      > Controlling 75 watts with such a small package means it's
      > almost certainly PWM

      If it was MPPT, that would be the lead story. In big print.
      With the usual overly optimistic "best case" efficiency
      figures.

      MPPT really starts making sense when the panel is putting out
      30 volts or more and you are trying to charge a 12v battery.

      Jerry, KE7ER
    • n1rx
      Just reading the specs, one can see it has no internal regulator: INPUTS Rated Wattage: 30W Cell Type: Mono-crystalline Open-Circuit Voltage: 18-20V Converting
      Message 2 of 30 , Mar 25 10:21 AM
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        Just reading the specs, one can see it has no internal regulator:

        INPUTS
        Rated Wattage:
        30W
        Cell Type:
        Mono-crystalline
        Open-Circuit Voltage:
        18-20V
        Converting Efficiency:
        17-18%
        Output
        12V Charging Port (4.7mm)
        14-16V, 2.0A max (30W), not regulated


        --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
        >
        > Guys,
        >
        > I am looking at the GoalZero Escape 30 briefcase. Do you know if it has an internal regulator or is it raw voltage from the solar panels out to the whacky 4.7mm plug. Me thinks it raw unfiltered, unregulated voltage direct from the panels but wanted to ask someone. I plan to use that with my AnyVolt3 (when that comes in).
        >
        > Myron WVØH
        > Printed on Recycled Data
        >
        > On Mar 24, 2013, at 8:33 PM, "luke_308" <aurich85@...> wrote:
        >
        > > Here's an option I recently came across. It's a miniature switching voltage regulator rated to 3 Amps. I have not yet tested one to check for RFI but plan on doing so in the next week or two. http://www.dimensionengineering.com/products/de-swadj3
        > >
        > > I have a Goal Zero 13 solar panel and was told by Goal Zero directly that it's Chain-In port was regulated to 15v max but in fact it puts out close to 21v. I think I'll try the SWADJ3 to bring it down to more radio friendly voltages!
        > >
        > > Luke
        > > KD0FIN
        > >
        > >
        >
      • jgaffke
        Bruce, If that s for the same panel as the one I pointed to http://www.goalzero.com/creative/assets/guides/Nomad13.pdf then they have slightly conflicting
        Message 3 of 30 , Mar 25 10:37 AM
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          Bruce,

          If that's for the same panel as the one I pointed to
          http://www.goalzero.com/creative/assets/guides/Nomad13.pdf
          then they have slightly conflicting specs.
          Mine says: 12V DC output 13-15V, 0-1A (13W max), not regulated
          and also, somewhere else: Open Circuit Voltage: 18-20V
          My assumption was that the 12V DC output was at least partially
          regulated to a max of 15V, 16V in your case, even with zero
          current draw. And that there was some other output for the raw
          panel voltage where one might see up to 20V.
          An equally plausible explanation is that the specs are bunk.

          Jerry, KE7ER

          --- In AT_Sprint@yahoogroups.com, "n1rx" <bruce.beford@...> wrote:
          > Just reading the specs, one can see it has no internal regulator:
          > ...12V Charging Port (4.7mm)14-16V, 2.0A max (30W),not regulated
        • n1rx
          Hi, Jerry. The text I quoted was from Goal Zero s spec sheet PDF from the website. The instruction sheet you link to below, does seem to _imply_ that there
          Message 4 of 30 , Mar 25 11:11 AM
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            Hi, Jerry.
            The text I quoted was from Goal Zero's spec sheet PDF from the website. The "instruction sheet" you link to below, does seem to _imply_ that there may be a clamp on the DC output, limiting it to 15v. But, I would assume it doesn't, and plan to use it as if unregulated. Or, find someone who has one, and ask them to measure the unloaded output voltage in full sun...
            73,
            bruce

            --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
            >
            > Bruce,
            >
            > If that's for the same panel as the one I pointed to
            > http://www.goalzero.com/creative/assets/guides/Nomad13.pdf
            > then they have slightly conflicting specs.
            > Mine says: 12V DC output 13-15V, 0-1A (13W max), not regulated
            > and also, somewhere else: Open Circuit Voltage: 18-20V
            > My assumption was that the 12V DC output was at least partially
            > regulated to a max of 15V, 16V in your case, even with zero
            > current draw. And that there was some other output for the raw
            > panel voltage where one might see up to 20V.
            > An equally plausible explanation is that the specs are bunk.
            >
            > Jerry, KE7ER
          • WVØH
            I guess the bottom line for me is can the Escape 30 be attached to the input of an AnyVolt3 (after some rewiring or plug mods) to charge a 12V SLA to some
            Message 5 of 30 , Mar 25 11:38 AM
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              I guess the bottom line for me is can the Escape 30 be attached to the input of an AnyVolt3 (after some rewiring or plug mods) to charge a 12V SLA to some degree? I say "some degree" because there is not the added efficiency of an MPPT controller and I'd probably choose 13.8-14.0 Volts output to float my SLA. I'll probably go with Anderson PP through out the system.

              The next thing is how noisy is the AnyVolt3? Anybody use this out in the field next to an antenna?

              Myron WVØH
              Printed on Recycled Data

              On Mar 25, 2013, at 12:11 PM, "n1rx" <bruce.beford@...> wrote:

               

              Hi, Jerry.
              The text I quoted was from Goal Zero's spec sheet PDF from the website. The "instruction sheet" you link to below, does seem to _imply_ that there may be a clamp on the DC output, limiting it to 15v. But, I would assume it doesn't, and plan to use it as if unregulated. Or, find someone who has one, and ask them to measure the unloaded output voltage in full sun...
              73,
              bruce

              --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
              >
              > Bruce,
              >
              > If that's for the same panel as the one I pointed to
              > http://www.goalzero.com/creative/assets/guides/Nomad13.pdf
              > then they have slightly conflicting specs.
              > Mine says: 12V DC output 13-15V, 0-1A (13W max), not regulated
              > and also, somewhere else: Open Circuit Voltage: 18-20V
              > My assumption was that the 12V DC output was at least partially
              > regulated to a max of 15V, 16V in your case, even with zero
              > current draw. And that there was some other output for the raw
              > panel voltage where one might see up to 20V.
              > An equally plausible explanation is that the specs are bunk.
              >
              > Jerry, KE7ER

            • jgaffke
              The AnyVolt3 is not going to do much good on a PV panel. It needs to monitor the input voltage as well, and keep that up in the region of maximum power for
              Message 6 of 30 , Mar 25 12:49 PM
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                The AnyVolt3 is not going to do much good on a PV panel.
                It needs to monitor the input voltage as well, and keep that
                up in the region of maximum power for that panel. Otherwise
                it's no better than a linear regulator, and probably worse.

                --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                > ...can the Escape 30 be attached to the input of an AnyVolt3...

                Regarding that $14 HF panel:

                The red HF panels I got were designed for a 12v lead acid battery.
                This new one claims to be good for a 12v or 24v battery. No
                switch, so might waste more power than my red one on a 12v load.
                Many of the reviews talk about how it warps into a pretzel when
                left in the dash. Cool if true, means it's built all of
                lightweight plastic. The boilerplate in the manual is quite
                amusing. Suggests you hire a qualified electrician if doing a
                grid tie. And how big a wire you need to carry 200 Amps. Nothing
                informative, like weight, Vmp or Voc (max power, open circuit).

                --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
                > Here's a $14 1W solar panel, often on sale for less...
                > http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html

                And here's some nice but very spendy rollables:
                http://californiapc.com/index.php?l=product_list&c=174

                Jerry, KE7ER
              • WVØH
                Why won t the AV3 work on an 18-20 V panel? Myron WVØH Printed on Recycled Data ... Why won t the AV3 work on an 18-20 V panel? Myron WVØH Printed on
                Message 7 of 30 , Mar 25 2:30 PM
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                  Why won't the AV3 work on an 18-20 V panel?

                  Myron WVØH
                  Printed on Recycled Data

                  On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:

                   

                  The AnyVolt3 is not going to do much good on a PV panel.
                  It needs to monitor the input voltage as well, and keep that
                  up in the region of maximum power for that panel. Otherwise
                  it's no better than a linear regulator, and probably worse.

                  --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                  > ...can the Escape 30 be attached to the input of an AnyVolt3...

                  Regarding that $14 HF panel:

                  The red HF panels I got were designed for a 12v lead acid battery.
                  This new one claims to be good for a 12v or 24v battery. No
                  switch, so might waste more power than my red one on a 12v load.
                  Many of the reviews talk about how it warps into a pretzel when
                  left in the dash. Cool if true, means it's built all of
                  lightweight plastic. The boilerplate in the manual is quite
                  amusing. Suggests you hire a qualified electrician if doing a
                  grid tie. And how big a wire you need to carry 200 Amps. Nothing
                  informative, like weight, Vmp or Voc (max power, open circuit).

                  --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
                  > Here's a $14 1W solar panel, often on sale for less...
                  > http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html

                  And here's some nice but very spendy rollables:
                  http://californiapc.com/index.php?l=product_list&c=174

                  Jerry, KE7ER

                • cloud runner
                  Perhaps another question might be, why would you want it to work? Why not use a proper charge controller which at that amperage would cost less than half as
                  Message 8 of 30 , Mar 25 4:32 PM
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                    Perhaps another question might be, why would you want it to work?  Why not use a proper charge controller which at that amperage would cost less than half as much as the anyvolt?
                     
                    See if you can find the Micro M+ charge controller kit.
                     
                    I don't understand why you want a solar collector at all, though.  The MTR uses so little current, that a 3 oz LiPO will power it for about three hours of continuous operation.  An 8 oz LiPO will power it for 24 hours of operation EZ.
                     
                    73  fred - kt5x
                     
                    - 

                    Why won't the AV3 work on an 18-20 V panel?

                    Myron WVØH
                    Printed on Recycled Data

                    On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:

                     

                    The AnyVolt3 is not going to do much good on a PV panel.
                    It needs to monitor the input voltage as well, and keep that
                    up in the region of maximum power for that panel. Otherwise
                    it's no better than a linear regulator, and probably worse.

                    --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                    > ...can the Escape 30 be attached to the input of an AnyVolt3...

                    Regarding that $14 HF panel:

                    The red HF panels I got were designed for a 12v lead acid battery.
                    This new one claims to be good for a 12v or 24v battery. No
                    switch, so might waste more power than my red one on a 12v load.
                    Many of the reviews talk about how it warps into a pretzel when
                    left in the dash. Cool if true, means it's built all of
                    lightweight plastic. The boilerplate in the manual is quite
                    amusing. Suggests you hire a qualified electrician if doing a
                    grid tie. And how big a wire you need to carry 200 Amps. Nothing
                    informative, like weight, Vmp or Voc (max power, open circuit).

                    --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
                    > Here's a $14 1W solar panel, often on sale for less...
                    > http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html

                    And here's some nice but very spendy rollables:
                    http://californiapc.com/index.php?l=product_list&c=174

                    Jerry, KE7ER

                  • jgaffke
                    Myron, The AV3 is a fairly standard buck-boost switching power supply. It can efficiently convert a higher voltage to a lower voltage (and vice versa), trading
                    Message 9 of 30 , Mar 25 5:15 PM
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                      Myron,

                      The AV3 is a fairly standard buck-boost switching power supply.
                      It can efficiently convert a higher voltage to a lower voltage
                      (and vice versa), trading volts for amps by making use of the
                      flywheel effect an inductor has on current flow. But it is
                      concerned only with regulating the output voltage.

                      Assume you put a 15 watt panel on the input and
                      a car battery discharged to 11 volts on the output.
                      The power supply will try to give as much current
                      as needed to bring the output up to 14 volts.
                      The panel can't supply that much current, so the voltage
                      from the panel into the power supply will drop until the
                      current is down around the amp that the panel can manage.
                      And voltage into the battery will be something a little over
                      that 11 volts you started with, slowly building up over time.
                      You'd be just as well off tying the panel directly to the battery,
                      and disconnecting when the battery reaches a charged state.
                      Or using a linear regulator, or it's chopper cousin the
                      PWM regulator. A PWM regulator does not have an inductor, so
                      does not have the efficiency of the AV3 switcher (or an MPPT
                      charge controller) in converting a higher voltage to a
                      lower voltage.

                      If the AV3 had an adjustment for maximum current (it does not),
                      you'd find as you fiddled with that knob that there's a setting
                      for which the current into the battery peaked, at somewhat
                      more current than you got just connecting the panel to the battery.
                      But when the sun angle changes a bit and not as much light
                      strikes the panel, you'd have to find that setting again.
                      So you sit there with a voltmeter on the panel, continuously
                      adjusting that maximum current knob, trying to keep the panel
                      voltage somewhere near the Maximum Power Point for that panel.
                      On panels built to charge a 12v battery through a PWM charge
                      controller, that is typically around 18 volts. There are
                      voltage losses through wires and charge controllers, and lead
                      acid batteries occasionally should have an equalization voltage
                      of 15 volts or so to reduce sulfate films on the plates, hence
                      the extra 6 volts beyond what you might expect. An MPPT charge
                      controller handles that current limit knob for you automatically,
                      keeping the panel voltage up around 18 volts. In fact it
                      automatically finds that special voltage (of 18 volts in my
                      example) at which it gets maximum power from the panel,
                      by constantly adjusting the current into the battery in
                      search of the panels maximum power point.

                      Way more than you wanted to know, I'm sure.


                      > I don't understand why you want a solar collector at all, though.

                      Fred,

                      May not make too much sense on a days outing, but would if out
                      for a month. Especially if you have other stuff using
                      batteries. And some people just like to understand stuff.

                      Jerry, KE7ER



                      --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                      > Why won't the AV3 work on an 18-20 V panel?

                      > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:
                      > > The AnyVolt3 is not going to do much good on a PV panel.
                      > > It needs to monitor the input voltage as well, and keep that
                      > > up in the region of maximum power for that panel. Otherwise
                      > > it's no better than a linear regulator, and probably worse.
                    • WVØH
                      Thanks Jerry, I m just starting to understand this a bit more everyday now. Yeah, the general current consumption of QRP rigs these days is so small that any
                      Message 10 of 30 , Mar 25 6:28 PM
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                        Thanks Jerry, I'm just starting to understand this a bit more everyday now. Yeah, the general current consumption of QRP rigs these days is so small that any battery of any size will work for weeks! I wanted to just understand why an MPPT controller is better, now I know. I have seen some MPPT controllers for as little as $65 but I'm sure that Morningstar has some less expensive, or at least non-MPPT controllers.

                        Thanks again.

                        Myron WVØH
                        Printed on Recycled Data

                        On Mar 25, 2013, at 6:15 PM, "jgaffke" <jgaffke@...> wrote:

                         

                        Myron,

                        The AV3 is a fairly standard buck-boost switching power supply.
                        It can efficiently convert a higher voltage to a lower voltage
                        (and vice versa), trading volts for amps by making use of the
                        flywheel effect an inductor has on current flow. But it is
                        concerned only with regulating the output voltage.

                        Assume you put a 15 watt panel on the input and
                        a car battery discharged to 11 volts on the output.
                        The power supply will try to give as much current
                        as needed to bring the output up to 14 volts.
                        The panel can't supply that much current, so the voltage
                        from the panel into the power supply will drop until the
                        current is down around the amp that the panel can manage.
                        And voltage into the battery will be something a little over
                        that 11 volts you started with, slowly building up over time.
                        You'd be just as well off tying the panel directly to the battery,
                        and disconnecting when the battery reaches a charged state.
                        Or using a linear regulator, or it's chopper cousin the
                        PWM regulator. A PWM regulator does not have an inductor, so
                        does not have the efficiency of the AV3 switcher (or an MPPT
                        charge controller) in converting a higher voltage to a
                        lower voltage.

                        If the AV3 had an adjustment for maximum current (it does not),
                        you'd find as you fiddled with that knob that there's a setting
                        for which the current into the battery peaked, at somewhat
                        more current than you got just connecting the panel to the battery.
                        But when the sun angle changes a bit and not as much light
                        strikes the panel, you'd have to find that setting again.
                        So you sit there with a voltmeter on the panel, continuously
                        adjusting that maximum current knob, trying to keep the panel
                        voltage somewhere near the Maximum Power Point for that panel.
                        On panels built to charge a 12v battery through a PWM charge
                        controller, that is typically around 18 volts. There are
                        voltage losses through wires and charge controllers, and lead
                        acid batteries occasionally should have an equalization voltage
                        of 15 volts or so to reduce sulfate films on the plates, hence
                        the extra 6 volts beyond what you might expect. An MPPT charge
                        controller handles that current limit knob for you automatically,
                        keeping the panel voltage up around 18 volts. In fact it
                        automatically finds that special voltage (of 18 volts in my
                        example) at which it gets maximum power from the panel,
                        by constantly adjusting the current into the battery in
                        search of the panels maximum power point.

                        Way more than you wanted to know, I'm sure.

                        > I don't understand why you want a solar collector at all, though.

                        Fred,

                        May not make too much sense on a days outing, but would if out
                        for a month. Especially if you have other stuff using
                        batteries. And some people just like to understand stuff.

                        Jerry, KE7ER

                        --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                        > Why won't the AV3 work on an 18-20 V panel?

                        > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:
                        > > The AnyVolt3 is not going to do much good on a PV panel.
                        > > It needs to monitor the input voltage as well, and keep that
                        > > up in the region of maximum power for that panel. Otherwise
                        > > it's no better than a linear regulator, and probably worse.

                      • jgaffke
                        ... That sentence above is not quite right. What the MPPT does is figure out a panel voltage that gives max power (typically around 18 volts on these panels),
                        Message 11 of 30 , Mar 25 6:37 PM
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                          --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@...> wrote:
                          > If the AV3 had an adjustment for maximum current (it does not),
                          > you'd find as you fiddled with that knob that there's a setting
                          > for which the current into the battery peaked, at somewhat
                          > more current than you got just connecting the panel to the battery.

                          That sentence above is not quite right.
                          What the MPPT does is figure out a panel voltage that gives max power
                          (typically around 18 volts on these panels), and then varies
                          the output current to try to maintain that input desired voltage.

                          The AV3 can't do that, all it looks at is the output voltage.

                          Jerry
                        • luke_308
                          I don t understand why you want a solar collector at all, though : Because not everybody returns to their cozy shack to recharge their batteries after every
                          Message 12 of 30 , Mar 25 8:37 PM
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                            "I don't understand why you want a solar collector at all, though": Because not everybody returns to their cozy shack to recharge their batteries after every outing, or because your standard plug-in charge controller is rendered useless if the next natural disaster or military attack knocks the power grid offline for any significant amount of time, or maybe I just think it's fun to use a natural, inexpensive and virtually endless power supply to run my toys...

                            Luke
                            KD0FIN

                            --- In AT_Sprint@yahoogroups.com, "cloud runner" <just.one.hill@...> wrote:
                            >
                            > Perhaps another question might be, why would you want it to work? Why not use a proper charge controller which at that amperage would cost less than half as much as the anyvolt?
                            >
                            > See if you can find the Micro M+ charge controller kit.
                            >
                            > I don't understand why you want a solar collector at all, though. The MTR uses so little current, that a 3 oz LiPO will power it for about three hours of continuous operation. An 8 oz LiPO will power it for 24 hours of operation EZ.
                            >
                            > 73 fred - kt5x
                            >
                            > -
                            >
                            > Why won't the AV3 work on an 18-20 V panel?
                            >
                            > Myron WVØH
                            > Printed on Recycled Data
                            >
                            > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:
                            >
                            >
                            >
                            > The AnyVolt3 is not going to do much good on a PV panel.
                            > It needs to monitor the input voltage as well, and keep that
                            > up in the region of maximum power for that panel. Otherwise
                            > it's no better than a linear regulator, and probably worse.
                            >
                            > --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@> wrote:
                            > > ...can the Escape 30 be attached to the input of an AnyVolt3...
                            >
                            > Regarding that $14 HF panel:
                            >
                            > The red HF panels I got were designed for a 12v lead acid battery.
                            > This new one claims to be good for a 12v or 24v battery. No
                            > switch, so might waste more power than my red one on a 12v load.
                            > Many of the reviews talk about how it warps into a pretzel when
                            > left in the dash. Cool if true, means it's built all of
                            > lightweight plastic. The boilerplate in the manual is quite
                            > amusing. Suggests you hire a qualified electrician if doing a
                            > grid tie. And how big a wire you need to carry 200 Amps. Nothing
                            > informative, like weight, Vmp or Voc (max power, open circuit).
                            >
                            > --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@> wrote:
                            > > Here's a $14 1W solar panel, often on sale for less...
                            > > http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
                            >
                            > And here's some nice but very spendy rollables:
                            > http://californiapc.com/index.php?l=product_list&c=174
                            >
                            > Jerry, KE7ER
                            >
                          • jgaffke
                            That Micro M+ charge controller is a really good steer. http://www.repeater-builder.com/backup-power/pdfs/the-micro-m-plus-charge-controller.pdf I d call it
                            Message 13 of 30 , Mar 25 9:14 PM
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                              That "Micro M+" charge controller is a really good steer.
                              http://www.repeater-builder.com/backup-power/pdfs/the-micro-m-plus-charge-controller.pdf

                              I'd call it a series PWM charge controller, except it takes
                              seconds to cycle, so virtually no radio hash.
                              Unfortunately the SunlightEnergySystems website where the kits
                              are sold is down just now, I sent email to ask if that's
                              long term.

                              If there was a spare pin on the MSP430, could implement it
                              with little more than a NDT2955 PFET pass transistor like the
                              one Steve uses to key the rig. If the MSP430 senses the
                              battery voltage is low, it turns on the PFET to send power
                              from the panel to the battery for however long it takes
                              for the voltage to rise up to the "fully charged" level.
                              Then the MSP430 turns the PFET off for 4 seconds
                              before inspecting the voltage again. Need a small panel,
                              sized for the desired battery charge current. And should have
                              some fail safe way to shut down the PFET if the code in the
                              MSP430 runs off the rails.

                              As always, not necessarily a good idea.
                              But fun to think about.

                              Jerry, KE7ER

                              > --- In AT_Sprint@yahoogroups.com, "cloud runner" wrote:
                              > See if you can find the Micro M+ charge controller kit.
                            • WVØH
                              One last question and I ll be done. If I have a panel that cannot source the current requirement of the load, the MPPT configuration is the way to go. If
                              Message 14 of 30 , Mar 26 5:36 AM
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                                One last question and I'll be done.

                                If I have a panel that cannot source the current requirement of the load, the MPPT configuration is the way to go. If however I have a large array that can source more than the load draws pretty much any regulator can work right? PWM higher efficiency, linear no RFI.

                                Is there a website that covers all of the basics of charge controllers and is comprehensive enough to satisfy the EE in me.

                                Thanks,
                                Myron WVØH
                                Printed on Recycled Data

                                On Mar 25, 2013, at 7:28 PM, WVØH <s9plus@...> wrote:

                                 

                                Thanks Jerry, I'm just starting to understand this a bit more everyday now. Yeah, the general current consumption of QRP rigs these days is so small that any battery of any size will work for weeks! I wanted to just understand why an MPPT controller is better, now I know. I have seen some MPPT controllers for as little as $65 but I'm sure that Morningstar has some less expensive, or at least non-MPPT controllers.

                                Thanks again.

                                Myron WVØH
                                Printed on Recycled Data

                                On Mar 25, 2013, at 6:15 PM, "jgaffke" <jgaffke@...> wrote:

                                 

                                Myron,

                                The AV3 is a fairly standard buck-boost switching power supply.
                                It can efficiently convert a higher voltage to a lower voltage
                                (and vice versa), trading volts for amps by making use of the
                                flywheel effect an inductor has on current flow. But it is
                                concerned only with regulating the output voltage.

                                Assume you put a 15 watt panel on the input and
                                a car battery discharged to 11 volts on the output.
                                The power supply will try to give as much current
                                as needed to bring the output up to 14 volts.
                                The panel can't supply that much current, so the voltage
                                from the panel into the power supply will drop until the
                                current is down around the amp that the panel can manage.
                                And voltage into the battery will be something a little over
                                that 11 volts you started with, slowly building up over time.
                                You'd be just as well off tying the panel directly to the battery,
                                and disconnecting when the battery reaches a charged state.
                                Or using a linear regulator, or it's chopper cousin the
                                PWM regulator. A PWM regulator does not have an inductor, so
                                does not have the efficiency of the AV3 switcher (or an MPPT
                                charge controller) in converting a higher voltage to a
                                lower voltage.

                                If the AV3 had an adjustment for maximum current (it does not),
                                you'd find as you fiddled with that knob that there's a setting
                                for which the current into the battery peaked, at somewhat
                                more current than you got just connecting the panel to the battery.
                                But when the sun angle changes a bit and not as much light
                                strikes the panel, you'd have to find that setting again.
                                So you sit there with a voltmeter on the panel, continuously
                                adjusting that maximum current knob, trying to keep the panel
                                voltage somewhere near the Maximum Power Point for that panel.
                                On panels built to charge a 12v battery through a PWM charge
                                controller, that is typically around 18 volts. There are
                                voltage losses through wires and charge controllers, and lead
                                acid batteries occasionally should have an equalization voltage
                                of 15 volts or so to reduce sulfate films on the plates, hence
                                the extra 6 volts beyond what you might expect. An MPPT charge
                                controller handles that current limit knob for you automatically,
                                keeping the panel voltage up around 18 volts. In fact it
                                automatically finds that special voltage (of 18 volts in my
                                example) at which it gets maximum power from the panel,
                                by constantly adjusting the current into the battery in
                                search of the panels maximum power point.

                                Way more than you wanted to know, I'm sure.

                                > I don't understand why you want a solar collector at all, though.

                                Fred,

                                May not make too much sense on a days outing, but would if out
                                for a month. Especially if you have other stuff using
                                batteries. And some people just like to understand stuff.

                                Jerry, KE7ER

                                --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                                > Why won't the AV3 work on an 18-20 V panel?

                                > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:
                                > > The AnyVolt3 is not going to do much good on a PV panel.
                                > > It needs to monitor the input voltage as well, and keep that
                                > > up in the region of maximum power for that panel. Otherwise
                                > > it's no better than a linear regulator, and probably worse.

                              • jgaffke
                                Myron, I wouldn t worry about MPPT unless the voltage at which the panel gives maximum power is much higher than the battery voltage. When going from 18 to 12
                                Message 15 of 30 , Mar 26 8:56 AM
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                                  Myron,

                                  I wouldn't worry about MPPT unless the voltage at which
                                  the panel gives maximum power is much higher than
                                  the battery voltage. When going from 18 to 12 (typical)
                                  the expense and complication is probably not worth the
                                  upgrade from PWM/Linear.

                                  The Micro M+ is a good choice for a ~12v PWM battery charger on
                                  panels anywhere between 0 and 4 Amps, it wastes virtually
                                  nothing to power itself. None of the heat of Linear, and
                                  slow enough that it doesn't have the RF hash typical of PWM.
                                  Mike says he'll probably have more kits by the end of April.
                                  Read the article I pointed to and then without pestering Mike
                                  too much (it's a hobby!) see if his website's up for kits:
                                  http://www.sunlightenergysystems.com

                                  If the panel cannot source the current requirement of the load,
                                  you probably need a battery in there somewhere.
                                  If by load you mean charging a battery, then what you really
                                  need is time for the voltage in the battery to build up.

                                  None of the solar panel battery chargers I've seen
                                  do current limiting, including the 80 Amp MPPT jobs
                                  costing the better part of $1K. If you put on enough panel
                                  to exceed the Amp rating of the charger (be it PWM or MPPT)
                                  you risk burning out the charger. You also want to make
                                  sure you don't have too many panels for your battery, they
                                  have a maximum charge rate in Amps as well.

                                  The assumption has always been you would be starved for panels
                                  at $5/watt. With some panels going for $0.50/watt on sunelec.com,
                                  it might be time for them to rethink. Would be trivial to add
                                  current sensing. I'd prefer extra panels, so I can avoid a
                                  generator through iffy weeks. And a water heater dump load.

                                  Excuse my punditry, head's been overflowing with this for months.
                                  I'm in the process of moving to an off grid house in the wilds
                                  of far NE Oregon, 2 hours from the nearest stoplight.

                                  I can't recommend one central information source, figured out
                                  what I have by scouring the web. And we know random sites on
                                  the web are always right.

                                  Jerry, KE7ER


                                  --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                                  > If I have a panel that cannot source the current requirement
                                  > of the load, the MPPT configuration is the way to go.
                                  > If however I have a large array that can source more than the
                                  > load draws pretty much any regulator can work right?
                                  > PWM higher efficiency, linear no RFI.

                                  > Is there a website that covers all of the basics of charge controllers and is comprehensive enough to satisfy the EE in me.
                                  >
                                  > Thanks,
                                  > Myron WVØH
                                  > Printed on Recycled Data
                                  >
                                  > On Mar 25, 2013, at 7:28 PM, WVØH <s9plus@...> wrote:
                                  >
                                  > > Thanks Jerry, I'm just starting to understand this a bit more everyday now. Yeah, the general current consumption of QRP rigs these days is so small that any battery of any size will work for weeks! I wanted to just understand why an MPPT controller is better, now I know. I have seen some MPPT controllers for as little as $65 but I'm sure that Morningstar has some less expensive, or at least non-MPPT controllers.
                                  > >
                                  > > Thanks again.
                                  > >
                                  > > Myron WVØH
                                  > > Printed on Recycled Data
                                  > >
                                  > > On Mar 25, 2013, at 6:15 PM, "jgaffke" <jgaffke@...> wrote:
                                  > >
                                  > >>
                                  > >> Myron,
                                  > >>
                                  > >> The AV3 is a fairly standard buck-boost switching power supply.
                                  > >> It can efficiently convert a higher voltage to a lower voltage
                                  > >> (and vice versa), trading volts for amps by making use of the
                                  > >> flywheel effect an inductor has on current flow. But it is
                                  > >> concerned only with regulating the output voltage.
                                  > >>
                                  > >> Assume you put a 15 watt panel on the input and
                                  > >> a car battery discharged to 11 volts on the output.
                                  > >> The power supply will try to give as much current
                                  > >> as needed to bring the output up to 14 volts.
                                  > >> The panel can't supply that much current, so the voltage
                                  > >> from the panel into the power supply will drop until the
                                  > >> current is down around the amp that the panel can manage.
                                  > >> And voltage into the battery will be something a little over
                                  > >> that 11 volts you started with, slowly building up over time.
                                  > >> You'd be just as well off tying the panel directly to the battery,
                                  > >> and disconnecting when the battery reaches a charged state.
                                  > >> Or using a linear regulator, or it's chopper cousin the
                                  > >> PWM regulator. A PWM regulator does not have an inductor, so
                                  > >> does not have the efficiency of the AV3 switcher (or an MPPT
                                  > >> charge controller) in converting a higher voltage to a
                                  > >> lower voltage.
                                  > >>
                                  > >> If the AV3 had an adjustment for maximum current (it does not),
                                  > >> you'd find as you fiddled with that knob that there's a setting
                                  > >> for which the current into the battery peaked, at somewhat
                                  > >> more current than you got just connecting the panel to the battery.
                                  > >> But when the sun angle changes a bit and not as much light
                                  > >> strikes the panel, you'd have to find that setting again.
                                  > >> So you sit there with a voltmeter on the panel, continuously
                                  > >> adjusting that maximum current knob, trying to keep the panel
                                  > >> voltage somewhere near the Maximum Power Point for that panel.
                                  > >> On panels built to charge a 12v battery through a PWM charge
                                  > >> controller, that is typically around 18 volts. There are
                                  > >> voltage losses through wires and charge controllers, and lead
                                  > >> acid batteries occasionally should have an equalization voltage
                                  > >> of 15 volts or so to reduce sulfate films on the plates, hence
                                  > >> the extra 6 volts beyond what you might expect. An MPPT charge
                                  > >> controller handles that current limit knob for you automatically,
                                  > >> keeping the panel voltage up around 18 volts. In fact it
                                  > >> automatically finds that special voltage (of 18 volts in my
                                  > >> example) at which it gets maximum power from the panel,
                                  > >> by constantly adjusting the current into the battery in
                                  > >> search of the panels maximum power point.
                                  > >>
                                  > >> Way more than you wanted to know, I'm sure.
                                  > >>
                                  > >> > I don't understand why you want a solar collector at all, though.
                                  > >>
                                  > >> Fred,
                                  > >>
                                  > >> May not make too much sense on a days outing, but would if out
                                  > >> for a month. Especially if you have other stuff using
                                  > >> batteries. And some people just like to understand stuff.
                                  > >>
                                  > >> Jerry, KE7ER
                                  > >>
                                  > >> --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@> wrote:
                                  > >> > Why won't the AV3 work on an 18-20 V panel?
                                  > >>
                                  > >> > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@> wrote:
                                  > >> > > The AnyVolt3 is not going to do much good on a PV panel.
                                  > >> > > It needs to monitor the input voltage as well, and keep that
                                  > >> > > up in the region of maximum power for that panel. Otherwise
                                  > >> > > it's no better than a linear regulator, and probably worse.
                                  > >
                                  > >
                                  >
                                • jgaffke
                                  ... Oh, wrong on that count too. PWM and linear give the same efficiency from a solar panel. If the battery voltage is low, they both just turn on and dump all
                                  Message 16 of 30 , Mar 26 11:32 AM
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                                    --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@...> wrote:
                                    > PWM higher efficiency

                                    Oh, wrong on that count too.

                                    PWM and linear give the same efficiency from a solar panel.
                                    If the battery voltage is low, they both just turn on and
                                    dump all available current from the panel into the battery,
                                    dragging the panel voltage down to that of the battery.
                                    With the lower panel voltage, the volts*amps from the panel
                                    is not delivering as much power as the panel could with MPPT.

                                    When the battery is nearly full, the linear limits the voltage
                                    by dissipating power in the pass transistor. The PWM sends
                                    pulses of all available current from the panel to the battery
                                    with the duty cycle adjusted to regulate the battery voltage.
                                    When PWM is not sending current to the battery that extra power
                                    is winding as heat in the panel. But the panel's relatively
                                    big, and only 10-15% efficient to begin with.

                                    MPPT adds an inductor, so it can efficiently convert all
                                    volts*amps from the panel down to the voltage the battery
                                    actually needs. Like your AV3 switcher, except the MPPT
                                    also has to keep the panel voltage up where the panel can
                                    deliver its maximum power. PWM does not have that inductor.

                                    > linear no RFI.

                                    Yup. Though the Micro M+ should do just fine on that score
                                    since it switches so slowly. The relatively long pulses of
                                    current into the battery might work the battery a bit harder,
                                    and the battery voltage might vary a bit more. But that's
                                    easier to deal with than the RF hash from most PWM chargers.

                                    Jerry, KE7ER
                                  • Mike Olbrisch
                                    Two words.... NORTH KOREA! . They are going to destroy us, dont ya know..... just watch the news. I have been on camping trips where there was no
                                    Message 17 of 30 , Mar 26 8:04 PM
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                                      Two words.... NORTH KOREA! <grin>. They are going to destroy us, dont ya
                                      know..... just watch the news.

                                      I have been on camping trips where there was no convenient way to charge
                                      anything. A good solar panel and some other parts, and you can get by for
                                      several days easy. In fact, I sometimes connect a 10-watt panel to the
                                      battery of my jeep, I do not drive it very often and it keeps the battery
                                      up.

                                      I have a 40-watt thin-flexible panel that folds up to the size of a
                                      notebook. Weighs 3 pounds, not bad, but still heavy for a single day's
                                      outing. A spare battery or three is far lighter than the panel. Even a
                                      spare battery for the FT-817 is still lighter.

                                      Talk about weight..... a funny story.... I was camping up in the Gila
                                      Wilderness. Parts of it really are wilderness. Me, my wife, one Great
                                      Dane, and my son who just returned from Iraq. This was a decompression trip
                                      for him. We drove in to town for something.... and when we returned there
                                      was another tent near us.... but curiously no car. I saw a lady outside
                                      working on something, so I went to offer her some help. I asked if their
                                      car broke down, and offered help, tools and a ride if they needed.

                                      She told me they were doing the continental divide trail, they had no car.
                                      So I offered her a couple of cold sodas, figuring that was something they
                                      didn't pack. She accepted. But a short while later she returned the sodas
                                      un-opened. She said the cans were too heavy to carry out as trash. They
                                      only had 1 small flashlight.

                                      I smiled and pointed to our 1-ton Ford van, told her it hauled trash just
                                      fine. She could toss the empty cans in my trash, and anything else they
                                      needed to dispose of. She was quite happy. We welcomed them to join us at
                                      our fire, and kinda just enjoyed the visit. The next morning they were off,
                                      and a bit lighter in pack weight too.

                                      Mike - KD9KC.

                                      -----Original Message-----
                                      From: AT_Sprint@yahoogroups.com [mailto:AT_Sprint@yahoogroups.com] On Behalf
                                      Of luke_308
                                      Sent: Monday, March 25, 2013 21:37
                                      To: AT_Sprint@yahoogroups.com
                                      Subject: [AT_Sprint] Re: Solar charging for MTR.

                                      "I don't understand why you want a solar collector at all, though": Because
                                      not everybody returns to their cozy shack to recharge their batteries after
                                      every outing, or because your standard plug-in charge controller is rendered
                                      useless if the next natural disaster or military attack knocks the power
                                      grid offline for any significant amount of time, or maybe I just think it's
                                      fun to use a natural, inexpensive and virtually endless power supply to run
                                      my toys...

                                      Luke
                                      KD0FIN

                                      --- In AT_Sprint@yahoogroups.com, "cloud runner" <just.one.hill@...> wrote:
                                      >
                                      > Perhaps another question might be, why would you want it to work? Why not
                                      use a proper charge controller which at that amperage would cost less than
                                      half as much as the anyvolt?
                                      >
                                      > See if you can find the Micro M+ charge controller kit.
                                      >
                                      > I don't understand why you want a solar collector at all, though. The MTR
                                      uses so little current, that a 3 oz LiPO will power it for about three hours
                                      of continuous operation. An 8 oz LiPO will power it for 24 hours of
                                      operation EZ.
                                      >
                                      > 73 fred - kt5x
                                      >
                                      > -
                                      >
                                      > Why won't the AV3 work on an 18-20 V panel?
                                      >
                                      > Myron WVØH
                                      > Printed on Recycled Data
                                      >
                                      > On Mar 25, 2013, at 1:49 PM, "jgaffke" <jgaffke@...> wrote:
                                      >
                                      >
                                      >
                                      > The AnyVolt3 is not going to do much good on a PV panel.
                                      > It needs to monitor the input voltage as well, and keep that
                                      > up in the region of maximum power for that panel. Otherwise
                                      > it's no better than a linear regulator, and probably worse.
                                      >
                                      > --- In AT_Sprint@yahoogroups.com, WVØH <s9plus@> wrote:
                                      > > ...can the Escape 30 be attached to the input of an AnyVolt3...
                                      >
                                      > Regarding that $14 HF panel:
                                      >
                                      > The red HF panels I got were designed for a 12v lead acid battery.
                                      > This new one claims to be good for a 12v or 24v battery. No
                                      > switch, so might waste more power than my red one on a 12v load.
                                      > Many of the reviews talk about how it warps into a pretzel when
                                      > left in the dash. Cool if true, means it's built all of
                                      > lightweight plastic. The boilerplate in the manual is quite
                                      > amusing. Suggests you hire a qualified electrician if doing a
                                      > grid tie. And how big a wire you need to carry 200 Amps. Nothing
                                      > informative, like weight, Vmp or Voc (max power, open circuit).
                                      >
                                      > --- In AT_Sprint@yahoogroups.com, "jgaffke" <jgaffke@> wrote:
                                      > > Here's a $14 1W solar panel, often on sale for less...
                                      > >
                                      http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html
                                      >
                                      > And here's some nice but very spendy rollables:
                                      > http://californiapc.com/index.php?l=product_list&c=174
                                      >
                                      > Jerry, KE7ER
                                      >



                                      ------------------------------------

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                                    • Gil G.
                                      Hello, Well, I went with the Goal Zero 7W solar panel that recharges four AA NiMH cells at a time... Got an eight-cell battery holder and sixteen 2850mAh
                                      Message 18 of 30 , Mar 26 8:33 PM
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                                        Hello,

                                        Well, I went with the Goal Zero 7W solar panel that recharges four AA
                                        NiMH cells at a time... Got an eight-cell battery holder and sixteen
                                        2850mAh batteries.. The LiPo solution was starting to look a bit too
                                        pricey and complicated. I opted for cheap & simple. Using AAs will also
                                        allow me to power other small devices, and recharge my iPod with the USB
                                        cable.

                                        You guys who use the MTR with eight cells, how long do you get?

                                        Thanks to all the replies by the way :-)

                                        Gil.
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