Why not get the biggest battery possible?

[jeep-N-montero]

From what I have heard, if a person has the space then a pair of the 6 volt RV house batteries would be a great setup because they have huge reserve capacity.

 

[PirateMcGee]

Hmm... 1/3rd the weight, about the same size, and theoretically the same capacity as an Odyssey G31: http://www.electriccarpartscompany....BMS-br-Can-Be-Paralleled-Up-to-48V_p_281.html

So at three times the price the question is: Can a LiFePo4 really deliver "up to 5 times" longer life versus an AGM under the same conditions?

http://www.electriccarpartscompany....-RV-Solar-br-Battery-Bank-Pack-Kit_p_617.html

 

[Chazz Layne]

http://www.electriccarpartscompany....-RV-Solar-br-Battery-Bank-Pack-Kit_p_617.html

That is sexy. Shame they're so picky about low temperatures though. The past month we've been getting into the low 20s and staying in the low 30s for several days at a time. Charging in those conditions would be a challenge.

 

[LeishaShannon]

That is sexy. Shame they're so picky about low temperatures though. The past month we've been getting into the low 20s and staying in the low 30s for several days at a time. Charging in those conditions would be a challenge.

That price doesn't appear to include the enclosure/strapping although thats not usually too expensive. I'd avoid solid busbars for vehicle use in favour of the braided flexible type - eg. http://www.evworks.com.au/braided-cell-interconnector-90-8

I'd also add a Victron BMV-702 so you know exactly how much juice is in the battery, they're not particularly tolerant of excessive charging or discharging.

 

[BigSwede]

http://store.starkpower.com/Starter-Batteries-Cars-Boats_c_38.html

 

[BigSwede]

I agree. If I have to choose, for example, between a single Grp 31 or a pair of Grp 34s, I'll take the 34s, regardless of the alternator I'm running.

Depends on what you are running. I use about 25 ah/day between my fridge and CPAP, so with my 100 ah grp 31 I can go two days and still be at 50%. If I have two grp 34s, my house battery would be at 26%, which would theoretically damage the battery significantly.

Not to mention a single grp 31 battery system is a lot simpler (and presumably more reliable), costs less than two grp 34 batteries plus the battery management system and wiring, and weighs less.

 

[BigSwede]

The "Biggest" battery isn't necessarily the most efficient battery. Also, "Big" batteries are not only significantly heavier, but take up additional space. It'd rather have a pair of smaller batteries and a very efficient alternator.

What two batteries would you use that weigh less and take up less room than a single group 31? I'm sure there are some out there, but they would have to be pretty small, and therefore fairly worthless as a house battery.