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- Dec 3, 2017
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Amp is flow, voltage is pressure, but power is watts. Three different parts of the equation. Time is part of it too. 1 amp hour is one amp for 1 hour. 900 amp hours is 1 amp for 900 hours.
Your 900 amp hour 12 volt has (amps times volts = watts) 10,800 watts stored while your 900 amp hour 24 volt battery has 21,600 watts stored. That shows that the 24 volt battery has twice the power (watts) as the 12 volt battery.
That is a very simplified way to show the power of a battery. In reality if you have a 900 amp load on both batteries they will not last a full hour because the voltage will drop very fast at those loads. Amp hour ratings are usually a 6 hour rate for industrial batteries and an 8 hour rate for commercial (retail purchase) batteries. That means that the industrial batter can take a higher load for a longer time than a commercial battery. The batteries can only produce so many amps at their nominal voltage for a given time. If you drain them faster the battery will produce less voltage trying to keep the amps up. That causes a loss of power.
I have attached a PDF that shows how the capacity of a battery is tested. The test is for a 12 volt battery but you can use the same test for a 24 volt battery by doubling the minimum voltage.
Thanks Sheep D. Our next project is to set up solar we bought a couple years ago. :thumbs up: