Determining AH rating of aging batteries
My Trojan 125's are almost 5 years old now, when they were new they were rated at 240 Ah. Now my trimetric is showing 70% at 12.1 volts which I know is wrong. So how can I determine the true Ah rati...
Forum Discussion
Fisherguy wrote:
Ya, I need to do it more often.
Past years I took the batteries out over the winter and charged them once a month, this past winter I left them on the trailer and plugged the trailer in once a month for a day, wonder what's best over the winter?
Best is leave the batteries on Float all the time, don't just run them up every so often, although that will get you by. One version is to wait until they get down to 12.4v and then recharge to 100% then let them go again. IMO if you have shore power use it full time.
If you don't like your trailer converter's float voltage you can get a special float charger. I like that Can Tire 2a one that sits at 13.4 once the batts are charged. (goes on sale about every three or four months for half price--20 vs 40 last I saw.)
On the weak cell now, it does recover with E but how long does it stay there with the batts on a 13.x float? Anyway the test did show plenty of capacity even with that weak cell. The unknown is how much longer can you keep getting what you want from that bank.
At least you know about it and can start saving up for replacements. Mex might know if they will die slowly or if you should worry about a sudden collapse while camping. (if so, I suppose you could swap in a 12v boat battery to replace those two batts and get by so it won't ruin that trip)
PS, off topic but while you are here, can you confirm you run your PD9280 off a 2000W Honda at 80a? Been some dispute whether that is possible. If you do please give some detail such as whether the converter's amps are tapering down anyway and how rapidly at the time so the Honda keeps running or if it can keep running the load at above 74ish amps for quite a while or what. Thanks.
