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Lithium ion battery rating

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  • normnet2003
    I recently purchased the following battery:
    Message 1 of 8 , Feb 18, 2013
      I recently purchased the following battery:
      http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e

      I planed to use it to power a device requiring 12 volts at 4 amps for 10-20 minutes however their doesn't seem to be any power when I plug the 4 amp device to the battery as opposed to plugging it into the car's 12 power supply.

      I thought 6800 ma meant 6.8 amps for one hour?
      What lithium ion battery rating should I order for a 12 volt 4 amp 10-20 minute requirement?


      Norm
    • Stefan Trethan
      Maybe there is a protection circuit inside the battery pack which limits the current to something less than 4 amp? I can find no specification for discharge
      Message 2 of 8 , Feb 18, 2013
        Maybe there is a protection circuit inside the battery pack which
        limits the current to something less than 4 amp?
        I can find no specification for discharge current.

        You do not exceed 1C discharge rate (6.8A) which most lithium
        batteries should support, so I believe it should not actually be the
        cells themselves limiting the performance.

        Personally I would open the pack up and have a look, but there is some
        serious risk of creating a fire hazard if you don't know what you are
        doing....

        A battery pack meant for RC model use would typically supply much
        higher currents, but may come without safety circuits.

        ST

        On Mon, Feb 18, 2013 at 1:56 PM, normnet2003 <normnet2@...> wrote:
        > I recently purchased the following battery:
        > http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e
        >
        > I planed to use it to power a device requiring 12 volts at 4 amps for 10-20 minutes however their doesn't seem to be any power when I plug the 4 amp device to the battery as opposed to plugging it into the car's 12 power supply.
        >
        > I thought 6800 ma meant 6.8 amps for one hour?
        > What lithium ion battery rating should I order for a 12 volt 4 amp 10-20 minute requirement?
        >
        >
        > Norm
        >
        >
      • Howard Hansen
        ... I see the battery comes with a built in on-off switch. By any chance did you forget to turn the battery on? The other Howard [Non-text portions of this
        Message 3 of 8 , Feb 18, 2013
          On 2/18/2013 6:56 AM, normnet2003 wrote:
          >
          > I recently purchased the following battery:
          > http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e
          >
          >
          > I planed to use it to power a device requiring 12 volts at 4 amps for
          > 10-20 minutes however their doesn't seem to be any power when I plug
          > the 4 amp device to the battery as opposed to plugging it into the
          > car's 12 power supply.
          >
          > I thought 6800 ma meant 6.8 amps for one hour?
          > What lithium ion battery rating should I order for a 12 volt 4 amp
          > 10-20 minute requirement?
          >
          > Norm
          >
          > __

          I see the battery comes with a built in on-off switch. By any chance did
          you forget to turn the battery on?

          The other Howard


          [Non-text portions of this message have been removed]
        • Frank Mead
          It will come to you not fully charged...charge it for 10 hours and give it a try... good advice howard. ... [Non-text portions of this message have been
          Message 4 of 8 , Feb 18, 2013
            It will come to you not fully charged...charge it for 10 hours and give it
            a try...
            good advice howard.


            On Mon, Feb 18, 2013 at 12:27 PM, Howard Hansen <hrhan@...> wrote:

            > **
            >
            >
            > On 2/18/2013 6:56 AM, normnet2003 wrote:
            > >
            > > I recently purchased the following battery:
            > >
            > http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e
            > >
            > >
            > > I planed to use it to power a device requiring 12 volts at 4 amps for
            > > 10-20 minutes however their doesn't seem to be any power when I plug
            > > the 4 amp device to the battery as opposed to plugging it into the
            > > car's 12 power supply.
            > >
            > > I thought 6800 ma meant 6.8 amps for one hour?
            > > What lithium ion battery rating should I order for a 12 volt 4 amp
            > > 10-20 minute requirement?
            > >
            > > Norm
            > >
            > > __
            >
            > I see the battery comes with a built in on-off switch. By any chance did
            > you forget to turn the battery on?
            >
            > The other Howard
            >
            > [Non-text portions of this message have been removed]
            >
            >
            >


            [Non-text portions of this message have been removed]
          • Larry Beaty
            A battery rated for 6800 MAhr or 6.8 Ahr really means it will put out 680 mA for 10 hours. That is how they cheat. In one hour, It may put out only 5.2 Amps
            Message 5 of 8 , Feb 18, 2013
              A battery rated for 6800 MAhr or 6.8 Ahr really means it will put out 680 mA
              for 10 hours. That is how they cheat. In one hour, It may put out only 5.2
              Amps for the hour. Specsmanship! Ain't it great!



              Larry



              From: Electronics_101@yahoogroups.com
              [mailto:Electronics_101@yahoogroups.com] On Behalf Of Howard Hansen
              Sent: Monday, February 18, 2013 1:28 PM
              To: Electronics_101@yahoogroups.com
              Subject: Re: [Electronics_101] Lithium ion battery rating





              On 2/18/2013 6:56 AM, normnet2003 wrote:
              >
              > I recently purchased the following battery:
              >
              http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Batter
              y-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries
              <http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Batte
              ry-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item3
              5bd1dd32e> &hash=item35bd1dd32e
              >
              >
              > I planed to use it to power a device requiring 12 volts at 4 amps for
              > 10-20 minutes however their doesn't seem to be any power when I plug
              > the 4 amp device to the battery as opposed to plugging it into the
              > car's 12 power supply.
              >
              > I thought 6800 ma meant 6.8 amps for one hour?
              > What lithium ion battery rating should I order for a 12 volt 4 amp
              > 10-20 minute requirement?
              >
              > Norm
              >
              > __

              I see the battery comes with a built in on-off switch. By any chance did
              you forget to turn the battery on?

              The other Howard

              [Non-text portions of this message have been removed]





              [Non-text portions of this message have been removed]
            • normnet2003
              I ll try charging it again just in case. Norm
              Message 6 of 8 , Feb 18, 2013
                I'll try charging it again just in case.

                Norm

                --- In Electronics_101@yahoogroups.com, Frank Mead <wa6ujj@...> wrote:
                >
                > It will come to you not fully charged...charge it for 10 hours and give it
                > a try...
                > good advice howard.
                >
                >
                > On Mon, Feb 18, 2013 at 12:27 PM, Howard Hansen <hrhan@...> wrote:
                >
                > > **
                > >
                > >
                > > On 2/18/2013 6:56 AM, normnet2003 wrote:
                > > >
                > > > I recently purchased the following battery:
                > > >
                > > http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e
                > > >
                > > >
                > > > I planed to use it to power a device requiring 12 volts at 4 amps for
                > > > 10-20 minutes however their doesn't seem to be any power when I plug
                > > > the 4 amp device to the battery as opposed to plugging it into the
                > > > car's 12 power supply.
                > > >
                > > > I thought 6800 ma meant 6.8 amps for one hour?
                > > > What lithium ion battery rating should I order for a 12 volt 4 amp
                > > > 10-20 minute requirement?
                > > >
                > > > Norm
                > > >
                > > > __
                > >
                > > I see the battery comes with a built in on-off switch. By any chance did
                > > you forget to turn the battery on?
                > >
                > > The other Howard
                > >
                > > [Non-text portions of this message have been removed]
                > >
                > >
                > >
                >
                >
                > [Non-text portions of this message have been removed]
                >
              • Andrew Mathison (Alice)
                I don t think discharging at close to the one hour rate to be a good idea. If there is a temperature sensor in the battery pack (there should be!) it will
                Message 7 of 8 , Feb 19, 2013
                  I don't think discharging at close to the one hour rate to be a good idea.
                  If there is a temperature sensor in the battery pack (there should be!) it
                  will probably open the circuit quite quickly, even before you feel the
                  temperature rise outside of the casing.....but maybe 5 minutes later......

                  The supplier should be in a position to tell you what the maximum discharge
                  current could be, but don't be surprised if it's only 680ma......

                  Also, new batteries might need to be charged/discharged several times before
                  full capacity is reached....depending upon chemistry and manufacturer....

                  Remember, the 6800ma is the quoted capacity, not the discharge
                  rate.....major difference.....

                  Regards

                  Andy
                • normnet2003
                  I let the battery charge for 24 hours with the switch on but no luck. Today I did an online chat with the enjoydeal store website and they replied the max amp
                  Message 8 of 8 , Feb 19, 2013
                    I let the battery charge for 24 hours with the switch on but no luck.
                    Today I did an online chat with the enjoydeal store website and they replied the max amp draw is about 1.5

                    I am going to look into RC batteries as Stephan said they are typically meant for higher output.

                    Norm

                    --- In Electronics_101@yahoogroups.com, "normnet2003" <normnet2@...> wrote:
                    >
                    >
                    >
                    > I'll try charging it again just in case.
                    >
                    > Norm
                    >
                    > --- In Electronics_101@yahoogroups.com, Frank Mead <wa6ujj@> wrote:
                    > >
                    > > It will come to you not fully charged...charge it for 10 hours and give it
                    > > a try...
                    > > good advice howard.
                    > >
                    > >
                    > > On Mon, Feb 18, 2013 at 12:27 PM, Howard Hansen <hrhan@> wrote:
                    > >
                    > > > **
                    > > >
                    > > >
                    > > > On 2/18/2013 6:56 AM, normnet2003 wrote:
                    > > > >
                    > > > > I recently purchased the following battery:
                    > > > >
                    > > > http://www.ebay.com/itm/6800mAh-DC-12V-Super-Rechargeable-Lithium-ion-Battery-Energy-Storage-Pack-/230806115118?pt=US_Rechargeable_Batteries&hash=item35bd1dd32e
                    > > > >
                    > > > >
                    > > > > I planed to use it to power a device requiring 12 volts at 4 amps for
                    > > > > 10-20 minutes however their doesn't seem to be any power when I plug
                    > > > > the 4 amp device to the battery as opposed to plugging it into the
                    > > > > car's 12 power supply.
                    > > > >
                    > > > > I thought 6800 ma meant 6.8 amps for one hour?
                    > > > > What lithium ion battery rating should I order for a 12 volt 4 amp
                    > > > > 10-20 minute requirement?
                    > > > >
                    > > > > Norm
                    > > > >
                    > > > > __
                    > > >
                    > > > I see the battery comes with a built in on-off switch. By any chance did
                    > > > you forget to turn the battery on?
                    > > >
                    > > > The other Howard
                    > > >
                    > > > [Non-text portions of this message have been removed]
                    > > >
                    > > >
                    > > >
                    > >
                    > >
                    > > [Non-text portions of this message have been removed]
                    > >
                    >
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