Simple way to measure coach battery capacity
I'm looking for a reasonably simple way to measure the current capacity of the single coach battery in my newly purchased (used) RV. I have a basic voltmeter which I don't think will be much help, ...
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Draw it down 50% of the original nominal capacity at the rate at which it earned that capacity and wait for voltage to rebound.
IE if it were rated 100AH at the 20 hour rate, apply a 5 amp load for 10 hours, remove the load, and wait a few hours for voltage to rebound.
If it rebounds to 12.2 or so, then the battery is still healthy.
By no means a perfect capacity test, but on a single battery of unknown age and condition it will give you a general idea.
IE if it were rated 100AH at the 20 hour rate, apply a 5 amp load for 10 hours, remove the load, and wait a few hours for voltage to rebound.
If it rebounds to 12.2 or so, then the battery is still healthy.
By no means a perfect capacity test, but on a single battery of unknown age and condition it will give you a general idea.
