Experiences with running fridge off main car battery overnight for a few nights in a row?

[67cj5]

IMO AGM's are the least suitable for recreational house use for most here, given the cost and short life span in these rather hodgepodge minimalistic setups.. Its nearly impossible for most to reap the benefits of agm in a boondocking setup, you are far more likely to expose their weaknesses IMO.

GC2 FLA's with a slow charge and discharge rate (0.05-0.1C) are perfectly suitable indoors and out, with simple monitoring, no pampering, and checking the levels a few times a year.. and if you do mess em all up and end up with some tractor ballast then its not such a impact to the budget, you have enough room to mess em all up several times over before you even reach entry point for some quality AGM's.

LFP is a whole another can of worms, but it makes AGM's look even less ideal as usable amp hour per dollar of high end AGM bring it within range of DIY LFP.

I agree, For the cost of one lithium battery I can buy 11.16Kw of battery power Off Grid deep cycle batteries, And for the cost of 2 good AGM's I can buy 2.76Kw of off grid batteries, And having such a reserve capacity of storage is much more appealing.

Have a look at these, and the spec's LOL

I can't believe the size of these things,

8 PZS 1240L 12V 14.88KW Off Grid Battery 8PZS1240L

12V Off Grid Traction Battery This battery contains 6 2volt traction cells. 2 Volt traction cells are perfect for off grid setups including solar and renewable installations thanks to their low self discharge and very deep cycling. They are guaranteed a longer life and higher capacity than...

www.tayna.co.uk

 

[john61ct]

The trouble is you get told that so many stories about AGM batteries it is hard to know what to believe

Easy enough to find and read the mfg tech docs.

Odyssey, Northstar and Lifeline's are well detailed.

Minimum charge rate for longevity on the former is 0.4C

 

[67cj5]

Yeah I always try to keep my charge rates down below the 10% mark but I have seen very high figures quoted for FLA/DC batteries and AGM's, When you consider the cost of a bank of FLA's or even a pair of AGM's it's just not worth the risk of damaging them with high charge rates.

 

[john61ct]

Again, wives' tales.

Only lead chemistry where too high a current might be an issue is GEL.

The key to not overcharging the sealed types is to stay within the reco voltage, and not hold CV/Absorb too long.

For quality FLA it is literally impossible to hold too long, nor go to too high amps, as long as you keep the water topped up.

The "max current" spec (if any) is lawyers' CYA, except as I said maybe for GEL.

 

[shade]

GC2 FLA's with a slow charge and discharge rate (0.05-0.1C) are perfectly suitable indoors and out, with simple monitoring, no pampering, and checking the levels a few times a year.. and if you do mess em all up and end up with some tractor ballast then its not such a impact to the budget, you have enough room to mess em all up several times over before you even reach entry point for some quality AGM's.

Certainly the simplest way to go.

 

[john61ct]

Best value on the planet