Battery float - storage voltage
I have 7 year old Lifeline AGM batteries that seem to be doing fine. Until recently I had a PWM single stage controller set at 13.7 volts. I have upgraded to a Blue Sky MPPT controller. This contro...
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Even better. I called Lifeline. For storage, batteries can be disconnected and left for months. Another option is to float at a little over 13 volts. I do not have a disconnect switch so I just programmed my Blue Sky so that the absorption and float voltages are just over 13 volts.
I was also told that my previous 13.7 volt single stage controller was set too high for a continuous charge. My 7 year old batteries are probably only able to muster about half the original amp hours. I explained I had tested the batteries using a light bulb and they still had 100 percent amp hours within the error of the testing. Apparently using a light bulb is pretty common and is a reasonable testing system short of spending $3000 for true scientific testing. I am in process of repeating my testing. The Lifeline tech recommended I continue with the same batteries. They are not likely to suddenly fail. If they don't hold up on the road, they can deliver new batteries to almost anywhere in the country within 2 days.
I was also told that my previous 13.7 volt single stage controller was set too high for a continuous charge. My 7 year old batteries are probably only able to muster about half the original amp hours. I explained I had tested the batteries using a light bulb and they still had 100 percent amp hours within the error of the testing. Apparently using a light bulb is pretty common and is a reasonable testing system short of spending $3000 for true scientific testing. I am in process of repeating my testing. The Lifeline tech recommended I continue with the same batteries. They are not likely to suddenly fail. If they don't hold up on the road, they can deliver new batteries to almost anywhere in the country within 2 days.
