Batteries

[Don77]

I have 2 12 volt group 27 deep cycle batteries that are about 2 years old that I removed from a trailer that I sold and I am wondering how long will they last if I put a smart charger on them once a month?
Thanks for any info.

Don

[LHaven]

Is there any reason you don't just leave them on the smart charger? Indoors, outdoors, weather, fluid checks? About the only sure thing you could do is bring them to an auto parts store for a free load test, and they'll tell you they are either ready to die or they aren't.

[Don77]

Too many other batteries that need to be maintained, 2 boats , 2 trailers, total of 8 batteries.

Don

[LHaven]

Got it. If you have to round-robin that many batteries you may find the idea behind this unit [LINK] interesting. It would reduce your maintenance to swapping four pigtails once a month. I never get over four batteries, so I just let the unit ride.

[GlasNav]

One of my uncles vessels in the late 60s, early 70s was DC, not AC. That means there were 11, 8D batteries that had to be maintained for the 120 V DC system. Then there were the main engine starting batteries 2 more 8D per engine, there wasn't a battery on the DC generator, that had a hand pump hydro starter. Then there was a bank of 4, 8D batteries in a battery box outside the wheelhouse for electronics.
Nineteen big *** lead acid batteries on one 100 ft vessel, and oh yeah, I had to maintain them, and was the only guy that happened to be around when the 11 had to be replaced. Hauling the old ones up out of the engine room and onto the dock and dragging the new ones down and installing.

[jxnbbl]

Once I got out trailer between snowmobiles, boat, trailer, boat lift motor (solar), car in winter storage, etc a lot of batteries of different types. I had to get 2 (4 bank and 2 bank) of these to cover the winter and then use the '2 bank' for the summer.

https://a.co/d/d48Lhe8

[Don77]

I rotate my charging monthly.
I was just wanting any ones take on how the 2 batteries would last on a shelf with monthly charging.

Don

[NH_Bulldog]

My RV batteries are coming up on 5 years old in April. They are installed in the camper in parallel and maintained by the converter/charger until early November. Then they sit on my workbench in the shop connected to a Battery Tender Jr. in parallel until they go back in the camper in April. The tender conditions the battery and prevents sulfation. I check level and maintain with distilled water several times a year. I can still boondock 3-4 days without a generator if needed so the batteries have held up well.