Inexpensive battery banks, any out there?

[pappawheely]

Looking to put together a couple solar systems; one mobile, and one stationary. The biggest expense is batteries. I looked at Lithium, but the recommendations were to not use them in high temps. I'm regularly in temps over 100 degrees, does that mean I should concentrate on agm, or lead acid? I'd like to hear some first hand experience before I get sucked in by the youtube experts.

 

[pluton]

Golf cart batteries seem to be the most capacity for the money. Don't know how vibration and shock resistant they are.

 

[llamalander]

AGM can be worth the extra cost if you need to mount them sideways or have very limited venting, otherwise traditional lead-acid will be more economical. If you're using them outside the ideal conditions, the capacity and lifespan will suffer, but it will still work, so economy probably becomes more important. Air or liquid cooling might help if you have surplus charging power, but that's just a guess...

 

[1leglance]

If weight and size is NOT an issue then the Costco 6v golf cart batteries are the cheapest per amp hour you can get. For the heat aspect I would use 12v computer fans to at least keep you at ambient or slightly under. You will only need them when the sun is shinning so the panels will give plenty of power. These would especially be good for your stationary setup.

I invested in lithium for my van due to space and weight concerns. Also I fully expect to get at least 10yrs from the battery which helps spread the cost. I get 160amp hours in the size of a group 31 at 40lbs vs 100Ahr (50% draw on a 200Ahr pack) in the space of 2 group 31 that were 150lbs.
Again if I could have given up the space and weight it is really hard to beat 6v golf cart batteries even if you replace them every few years (unlikely).

 

[dreadlocks]

Pair of GC2's are far better than anything for the money.. and still better than most everything 2x the money.. They take abuse very well and if your abuse does kill em they are cheap.. you can replace a GC2 bank several times for the price of a good AGM deep cycle bank and that premium AGM bank is very unlikely to last several times longer than GC2, if any longer at all.

 

[jkam]

I'm a fan of Trojan 6V T 105 flooded batteries.
I've had very good results using them in my RV for more than 12 years now.
First set lasted 8 years and I'm still on the second set now.
Not the cheapest available, but I'm happy to pay for years of service I've been getting from them.

 

[pappawheely]

Pair of GC2's are far better than anything for the money.. and still better than most everything 2x the money.. They take abuse very well and if your abuse does kill em they are cheap.. you can replace a GC2 bank several times for the price of a good AGM deep cycle bank and that premium AGM bank is very unlikely to last several times longer than GC2, if any longer at all.

OK, what's GC2?

 

[dreadlocks]

standard 6v Golf Cart batteries.. You can get a Duracell (Deka/EastPenn) from SamsClub for $89, a pair of em for $180 gives you a 215AH 12V bank..

GC2 batteries by design are true deep cycles, super thick and robust cells.. will take far more abuse than anything else you'll get until your several times this cost.

 

[Buddha.]

I’ve had two golf cart batteries in my travel trailer for the last three years. Got them at batteries plus. They live an easy life and I’ve never had to add water to them. I could if I needed to. Not all batteries are “refillable”.

If you go with golf cart batteries make sure you get 6v not 8v. I’ve seen people make that mistake.

 

[fitt]

Go to https://diysolarforum.com/ Will has a lot of good vids on youtube on solar

 

[pappawheely]

I'm planning to mount the battery inside so I'm leaning towards agm. How are these? https://www.amazon.com/gp/product/B075RGX1WR/ref=ox_sc_act_title_1?smid=ATVPDKIKX0DER&psc=1

 

[dreadlocks]

Garbage.. I made the mistake of buying a Renology AGM about a decade ago.. it crapped out after 2 short seasons... If your going AGM you needa be looking at Rolls or Lifeline.

What kind of loads are you expecting on this thing? FLA are generally pretty safe indoors unless you overcharge the hell outta em while your inside.. It takes very heavy loads to convert battery acid into any gasses.. my vehicle has designed with a H9 sized FLA right under my seat, in the passenger cabin.. what they did to prevent me and my passengers from harm? a simple DC-DC charging system that keeps the battery charged correctly instead of a dumb constant voltage alternator.. they been building this platform vehicle since 2003 and I've never seen anything but a nice clean battery under the seat, no signs of offgassing or spilt battery acid.

If this is powering a fridge or some lights, there is practically zero risk w/the battery sitting right next to where you sleep.. you need to start approaching the batteries max current output before this is a concern.. the only real advantage to AGM is if you have to build your bank on its side or something, other than that.. its got vents too if it starts offgassing and builds up too much pressure.

An external vent to your battery compartment higher than the battery posts would mitigate ALL issues w/bank indoors.. you can get nice GC2 battery boxes that can be vented very easy.

 

[pappawheely]

I'm not a sam's club member. I went on amazon looking for 6V batteries, but after 32 pages of the exact same 4.5 amp hour battery I gave up.

 

[dreadlocks]

You gotta buy your batteries locally dude, shipping em is is gonna cost you extra and then you wont have any good way to warranty it without paying more than its worth to ship it back in a few years.. Buying anything bigger than a Size D battery off Amazon is just dumb.. you'll get one thats already had half its life pissed away sitting on a shelf at best.. I learned this the hard way, dont do it.

The key word your looking for is GC2 thats the group size specification of these batteries.. Auto Stores, Battery Stores carry em, but Sams has the best deal.. EastPenn makes good batteries and if it had a Deka label on it at an auto store it'd be way more expensive than the duracell rebrands at Sams.

 

[1000arms]

Looking to put together a couple solar systems; one mobile, and one stationary. The biggest expense is batteries. I looked at Lithium, but the recommendations were to not use them in high temps. I'm regularly in temps over 100 degrees, ...

If you will be easily able to get replacement batteries, then a Sam's Club, Costco, or BJ's membership might be worth it just for access to the batteries, especially with 2 solar systems.

If replacing the batteries will be difficult due to location, stationary and/or mobile, then you might want to invest in the Trojan batteries mentioned above.

What voltage systems?

Will the mobile system be a copy of the stationary system for simplicity, or will the systems have different needs?

Is the stationary system at the top of a mountain only accessed by a steep hike followed by a technical climb? If so, you might want to look at Lithium batteries.

Will you need to be very careful of weight with the mobile system? Will you be mounting the batteries inside a temperature controlled living compartment, on a heavy duty trailer, on a horse-dragged travois, ...?

Definition of TRAVOIS

a simple vehicle used by Plains Indians consisting of two trailing poles serving as shafts and bearing a platform or net for the load… See the full definition

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