- Doing this in context below, hoping for clarity: ... P Never said that -- really no power loss in the fuse, but possibly some voltage drop in the supplyMessage 1 of 31 , Nov 13, 2012View SourceDoing this in context below, hoping for clarity:
On Tue, Nov 13, 2012 at 7:19 AM, Walter Lee <waltermlee@...> wrote:
> The Peter's reasoning goes as follows: the power loss from the input
> circuityr (fuse) to the actual power adapter is 30W ( 150w-120w) or 20%
> power loss in the adapter circuitry.
P> Never said that -- really no 'power loss' in the fuse, but possibly some
voltage drop in the supply circuit depending on wire size. Power
LIMITATION is the contacts in the plug connection.
> We supposing there is another 20% loss from from the 12VDC to 120VAC
> power inverter that would be 24W ( 120W-24W) = 96 W output which is under
> 100W output rating which is why Peter is suggesting the next popular power
> inverter max output rating of 80W - to avoid drawing a load greater than
> That is to say when getting an inverter we need to make sure that the
> 12VDC-to-120VAC inverter's maximum input power load does not exceed the
> 120w and not to get that mixed up with the advertised maximum output
> power load.
P> True - a matter of looking at load vs. output, and recognizing that the
former will always exceed the latter.
> The Prius Owner's Manual says that the Prius battery terminals under
> neath the hood (Jumpstarting section is on page 543-547 of Section 5-2 in
> the 2010 Prius Owner's manual but with the warning on page 547) is design
> only to jump start the Prius battery and is not designed to jump start
> another vehicle. However, it doesn't say anything about how it could be
> used to recharge another standalone battery. Why would recharging a
> standalone battery be safe but jumpstarting a vehicle would not safe?
P> Simply because it's possible for a jump-starting load (assuming
sufficiently robust jumper cables, which some are...) can easily exceed
100A and thus endanger disabling the car by popping that fu$e. Note that
we're now talking BIG-inverter, no longer the ciggy-lighter variety. With
an appropriately-chosen inverter and properly-sized dedicated fuse, the
danger to the internal 100A fu$e is minimized.
[Non-text portions of this message have been removed]
- ... I think you are trying to over think it. If the inverter can really put out 80W (most are sold by liars) then we know the input draw must be at least 80W.Message 31 of 31 , Nov 13, 2012View SourceOn Nov 13, 2012, at 6:19 AM, Walter Lee wrote:
> David,I think you are trying to over think it.
> I'd really am interested in this scenario and what my options are.
> I messed up last time - I don't want to mess up twice. (9_9)Can you confirm whether I am getting the basics correctly. (9_9)
> The Peter's reasoning goes as follows: the power loss from the input circuityr (fuse) to the actual power adapter is 30W ( 150w-120w) or 20% power loss in the adapter circuitry.
If the inverter can really put out 80W (most are sold by liars) then we know the input draw must be at least 80W. The Prius outlet is rated 120W. There is a conversion loss somewhere in your 80W inverter. So we say that an 80W inverter is about the limit of what one can safely use on a 120W supply. Perhaps you could get by with a 100W unit.
Truth be told 119W isn't going to be safe when 121W is a sure kill. These things are not that predictable. Gut feel from experience says 80W should be safe, 100W might be safe, and 120W rated inverter is certainly not safe at its full capacity because it will be drawing more than 120W.
David Kelly N4HHE, dkelly@...
Whom computers would destroy, they must first drive mad.