Quote:
Originally Posted by Chance
It's not that simple because Amp-hours IS NOT a measure of energy.
For example, 100 Amp-hours at 6 Volts is only half the "energy" as 100 Amp-hours at 12 Volts. And if we used a 48-Volt system like in many residential solar applications (and auto future) the difference (error) is even greater.
The best way to actually simplify these calculations is to use units of measure for energy, which for batteries is normally kWh (kilowatt-hour). That's how electric cars are rated because Amp-hours would be useless without also knowing voltage. RVs are "usually" 12 volt systems, but even that confuses a lot of people because batteries can be 6- or 12-Volt.
When you look at actual energy storage capacity of batteries, assuming same chemistry and battery weight, there is very little difference between 6- and 12-Volt batteries.
There is usually a "slight" advantage for the 6-Volt over 12-Volt because each cell is larger, requiring a little less packaging per pound of battery. If we only cared about maximizing Amp-hours per battery, we'd go to 2-Volt batteries.
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Actually, all we care about is Amp-Hours capacity at 12 volts.
Most people realize the AMP-Hours in 2 12 volt batteries in parallel are additive and the voltage in 6 volt batteries in series is additive, but the AMP-Hours are not.