Battery float - storage voltage

Actually it is difficult to get to my battery terminals. I removed the sliding tray in order to fit in the maximum sized batteries. I have about a quarter inch to spare above the batteries, absolutely no room front and back and maybe an inch on the sides. Dealing the a couple hundred pounds of battery under those circumstances is not something I want to do. I suppose I could put in a battery disconnect switch somewhere in the camper but that would take some doing and I would still need to disconnect and reconnect the batteries.

Programming the Blue Sky only took a minute and it will take the same minute to reprogram when I set out on my next adventure.

JimK-NY wrote:
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.

Those two sentences seem to contradict each other.

Is is too difficult to just disconnect one terminal?

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.

Go and get the manual from lifeline. Follow their recommendations.

JimK, Trojan AMGs unknown to me. Mine are old fashioned wet ones - T-125s. Float is 6.75 and for two in series duh! 13.50 per Trojan. So I float them at 13.50...unless they have a fight and separate for a while!

Once the batteries are fully charged in storage I would simply turn that controller off and disconnect the battery. OK to sit 4 to 6 months without issue.

Much better to have a controller that automatically adjusts absorption time depending on use.

Lifeline has a recommended float voltage. Depending on temp that is about 13.3 volts. That is why is seems unnecessary and perhaps harmful for a battery not in use to have a daily absorption cycle at much higher voltage. The Blue Sky absorption voltage does follow the recommendations from Lifeline.

What would you do with a Trojan battery? Maybe that manual is clearer.

I have no experience with Lifeline batteries but Trojan tells you all kinds of things about storage, voltage, charging etc. on-line. Have you checked with Lifeline? Makes good sense to me to ask the manufacturer. Just looked at their "Knowledge Center." Seems very informative.

No. With shaded panels I don't see a reason to do that.

Lifeline AGMs will hold a charge for a long time if they're fully charged then disconnected. I left mine for 8 months and they measured 12.6. That's not bad.