Thor Forums

[Chance]

I didn’t want to type much at midnight for fear of being half asleep.

When comparing Apples and Oranges, we have to start over because conditions are very different. While 800 to 1,000 Amps may sound crazy, it’s at 12V nominal, not 48V.

Looking at eight typical 6V golf cart butteries with ratings in the 200~225 Amp-hr range, if wired in 4 parallel strings of 2 batteries in series each to make a 12V system, the current per battery isn’t as bad as in the example.

I’m honestly impressed with capability to provide 540 Amps at 42 Volts, but that’s 23,000 Watts, in the range of three times more power than should be needed to start an efficient A/C. With minor A/C modifications it could be much less than that.

Realistically, even at 800 Amps at 12V nominal, each battery string would only see 200 Amps, and only for a few seconds. Voltage shouldn’t drop as badly as your 540 Amps.

Anyway, once inverters get large enough to power a typical roof-top RV air conditioner, I would personally avoid a 12V system. I’ve been a proponent of 48V systems for many years, and was glad to see Volta start the transition. Unfortunately, for most do-it-yourselvers, it’s a little early still.

We also have to keep in mind that many advanced DIY types are going to lithium batteries to save weight and space, and those batteries don’t have the same amount of voltage drop at high currents. There’s a lot to consider