Guess the truck camper needs a new battery :-(

Time to get back to this.

I camped over the weekend at our 4x4 site. Bright sunshine into early evening, then ran the generator for a coupe of hours, by about 4am the compressor fridge was cycling indicating the battery voltage had dropped too low for it.

I re-measured the tiny battery compartment - buried at the front of the camper under the seat and next to the water tank. Various fittings for the water tank and electrical cables mean that I can get a group 24 battery in regularly oriented, or a group 27 mounted upright.

I don't boondock that often, but I would like to be able to do it more for a night or two at a time.

My old battery was a group 24 80Ah "leisure battery" - i.e. little more than a cheap starting battery. I don't know how many cycles it could stand to 50% depth of discharge, but I suspect it would be in the tens. And 50% of 80Ah is of course only 40Ah. My compressor fridge draws 6 amps, so over 12 hours at 50% duty cycle that is 36Ah. So each night without hookup and I was pretty much dropping the battery to 50% DoD! So clearly I needs more available Ah. That could be a bigger battery if one could fit, or a battery that can be discharged further. Or both.

A data sheet on Lifeline AGM batteries shows the ability to be discharged by 80% 500 times. If that is realistic then it is maybe an answer to my problems - that would effectively give 80Ah out of an 100Ah for more boondocking nights than I am ever going to need it over 5 years. I.e. most of the time I would be discharging the battery maybe 10%, but occasionally I could go down to 80%.

There are many cheap AGM batteries these days, but I guess not all are equals.

I've seen adverts for batteries nearly a third of the price of the above Lifeline AGM, but that states a measly 180 discharges to 50% DoD.

So it sounds like Lifeline AGMs are good.

What other brands do people recommend I look at? Specifically ones known to be proper deep cycle - able to withstand hundreds of discharges to 80% DoD.

Or is that an unrealistic expectation and maybe I have failed to read something in the Lifeline small print.

Actually, here is another brand of battery whose specification sheet indicates > 500 cycles at 80% DoD:

Rolls AGM battery

I live in England, hence the above is a UK distributor and the price is in £ not $.

On another note, I realised the cheap Chinese volt / ammeter I installed was reading high. I have ordered a Victron 700 battery meter so I can more accurately monitor my replacement battery.

Steve.

....I could be a bit off, but I recall when I was looking at AGMs to replace flood cell lead-acid, almost every AGM manufacturer I looked at had a different casing size (length and/or width and/or height). So, for the most part, I had to shop dimensions, given our limited battery compartment space.

It's been a good run with what you had.
Trojan AGM
Get the biggest single or double that will fit your space.
AGMs have the glass matting and no sloshing fluid making them more suitable for rough duty.

tattoobob wrote:
Can't you use the Refrigerator on Propane?

"Compressor" means no.

Can't you use the Refrigerator on Propane?

I recently replaced mine, but I didn't try to optimize. The standard size batteries were too cheap to wait. I was making it through the night, but replacing gave me more of a buffer to run the furnace and inverter if I wanted.

This was the second replacement in 10 years, so that's not too bad.