profdant139 wrote:
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Is there a better way of doing this? Thanks in advance for your suggestions. Really clever answers that don't require the purchase of expensive testing equipment are particularly appreciated! ;)
I have been using AGMs since 2009. What is important to me is that my 12V systems do a day's work in a day. I gave up on wanting to track battery AHs.
Last year I installed 2 x 135AH used AGM telecom pulls that were 5 years old. I wanted a simple baseline test. I used a Magnum 1012 1000W/50A inverter charger to draw a constant 800W for 1:15. The draw was measured with through Kill-A-Watt until it showed 1.00KWHs. The ending Volts were 11.99. After 5min the Volts rebounded to 13.36. Volts were measured with a Turnigy. I figure if I can pull 1000WHs in this short time, I am very sure I will have no problem spreading 1000WHs over a day's use.
I will be repeating this capacity test in Nov. I expect about a 2% loss of capacity which means that I am looking for 11.75V at the end of the test.
I can't say if this is a better way.
HTH;
John
