Hi
I noticed the other day the capacity seemed down on my system, 3 by 113 Ah 12 V batteries linked together in parallel with 6in lengths of 50mm2 cable with soldered ring terminals. Working on the assumption that three batteries are not all going to die at the same time I removed the links from the positive terminals and checked the battery voltages, all within 0.25 of a volt. I then put a 55W car headlamp bulb across the batteries one at a time. Two of the batteries dropped to around 12.4 V then stabilised, the third battery continued to drop at about 0.1 V every 5 seconds to below 12 V.
I removed it from the system and connected it to a marine charger conditioner and let it run through one cycle, again put the load on it and monitored the voltage, it dropped to about 12.6 V then held fast for some time.
I put it back into the system and connected the charger conditioner, programmed it for a two hour program, ie. when the battery reaches the set point it maintains it for two hours, then drops into float mode.
I was quite surprised that three batteries connected with heavy cables could have such a difference in capacity. I normally every six or eight weeks give my set up an equalising charge, but it seems to have slipped my mind for a while.
It wont again I can't afford to buy batteries at the moment especially if it is my fault they died.
Brian
