BFL13 wrote:
"I started with a fully charged battery (which reads 12.9 V when it comes off the charger) and then let it rest for a day, so that the initial reading was 12.7 volts."
I don't understand this part. When I finish charging, the batts are still over 13v and it takes a couple days for the surface charge to get below 13v.
I would be worried if I got the quoted numbers.
He is using marine batteries (calcium) with likely 1.265 specific gravity acid (when new) as it is a thick plated starting battery the voltage fully charged would be around 12.7 also due to the plates being more porous the surface charge will go away much faster then a true deep cycle battery will.
specific gravity acid that is higher will have higher voltages.
