6 volt vs 12 volt batteries for boondocking

[placergold]

Hi all, While waiting for our new 28' Stealth toy hauler we're trying to figure out the best batteries to get for when we're back in the hills camped off the grid.

We ordered the optional 200 watt solar panel & regulator with Power Boost. And a 1,500 watt Go Power Inverter.

I've been told the golf cart type 6 volt batteries will last much longer than the 12 volt deep cycle batteries available. Mainly because of the constant discharge/charge cycle that occurs.

But, I really have no experience in this area, so any and all input from those familiar with this subject would be greatly appreciated!

Thank you.

[RDMueller]

As others have said, absolute best bang for the buck, hands down, the 6v golf cart batteries. I bought 2 Trojan T105s from a golf cart place for $260, but many people have had very good results with the Sams Club or Costco GC2s at a substantially lower price. They probably aren't quite as good as the Trojans, but still way better than any 12v marine battery.

If you really want to use the 1500w inverter for microwave, coffee, etc., either go with 4 GC2s or go with AGM. AGMs are great batteries, their only real drawback is the cost.

IMO, the 12v marine batteries are just about worthless if you plan to do much dry camping.

[marcsbigfoot20b]

Anyone have any feelings towards using say 3 of these batteries in parallel for boondocking?

Duracell AGM group 31 31DTMAGM

I have 1 as house batt and adding 2 more in parallel. Just installed 360 watts of solar. Converter is a WFCO 9855 3 stage.
Have a 2000 PSW inverter for microwave, Kurig, etc.

[garyemunson]

x@ on the 4 6 volt golf cart batteries. Splurge for a 'watering' system. Best gadget anyone has come up with for battery maintenance.

[MEXICOWANDERER]

And like Hillary Clinton they forgive and forget. NOT NICE MEX! COOL IT!

[ktmrfs]

theoldwizard1 wrote:

placergold wrote:
I've been told the golf cart type 6 volt batteries will last much longer than the 12 volt deep cycle batteries available. Mainly because of the constant discharge/charge cycle that occurs.

The real issue is cost and availability. TRUE "deep discharge" 12V batteries are not very common, or maybe I should are not found in most places that sell batteries. What you will find are "dual purpose" marine/RV batteries which will not last any where near as long (fewer cycles).

Golf cart batteries can be found at Costco, Sams and even some Walmart stores. They are moderately priced.

If you "premium" deep discharge batteries, they can be found at most solar energy stores. The 2 best brands are Trojan and Rolls. Both sell many different types of deep discharge batteries. The best are ones design for "renewable energy". Much more expensive than golf cart batteries, but this is a case of "you get what you pay for".

Both companies also sell deep discharge AGM batteries.

Even true deep discharge 12V like Trojan 12V renewable energy 12V have about 1/2 the cycle life of a similar 6V configuration. still way way better than a marine battery, so if your power draw is high they are a good alternative. And instead of 500 cycles, you may "ONLY" get 250. wow, for many RV apps, that just fine.

Issue is they aren't nearly as readily available as a golf cart

[ktmrfs]

placergold wrote:
ktmrfs, "but the downside to GC is high internal resistance, not ideal for heavy draws like a big inverter".

Q. Is a 1,500 watt Go Power inverter considered big?

my experience that I think has been verified by others.

A pair of GC batteries will drive a 1000W inverter untill the battery is down to around 80 percent SOC, then the inverter will alarm and shut down due to low input voltage. Now that means unless a pair is well charged, you may be out of luck even at 1000W.

4 GC batteries will run a 1000W inverter at full load down to near 50 percent. Why? well each pair of batteries is supplying 1/2 the total current draw. At least mine do.

So...... If you really want to draw 1500W from an inverter a pair of GC is not a good choice. 500W draw, probably ok, 1000W draw only on a nearly fully charged battery.

This is the downside of GC and where 12V marine or starting batteries shine. WAY WAY lower internal resistance partly because the have many many thin plates rather than a few thick plates. But that's why the don't like deep discharges either.

Now if that draw if for a microwave oven, here is a hint. buy a panasonic true inverter microwave. they don't cycle the power, the drop the magentron power. So in my case my 1500W panasonic microwave draws about 800VA at 50 percent power. works great on my 1000VA inverter, works great with my 4 GC batteries. And at 50 percent power it doesn't take twice as long to heat up something, maybe a third or so longer. Works great for reheating veggies, warming coffee, tea, etc.

[red31]

solar regulator with power boost, now that sounds like a new marketing term,

what is power boost and is it any dofferent that a normal controller (pwm/mppt)? or does it just cost more?

[theoldwizard1]

placergold wrote:
I've been told the golf cart type 6 volt batteries will last much longer than the 12 volt deep cycle batteries available. Mainly because of the constant discharge/charge cycle that occurs.

The real issue is cost and availability. TRUE "deep discharge" 12V batteries are not very common, or maybe I should are not found in most places that sell batteries. What you will find are "dual purpose" marine/RV batteries which will not last any where near as long (fewer cycles).

Golf cart batteries can be found at Costco, Sams and even some Walmart stores. They are moderately priced.

If you "premium" deep discharge batteries, they can be found at most solar energy stores. The 2 best brands are Trojan and Rolls. Both sell many different types of deep discharge batteries. The best are ones design for "renewable energy". Much more expensive than golf cart batteries, but this is a case of "you get what you pay for".

Both companies also sell deep discharge AGM batteries.

[placergold]

ktmrfs, "but the downside to GC is high internal resistance, not ideal for heavy draws like a big inverter".

Q. Is a 1,500 watt Go Power inverter considered big?

[red31]

MEXICOWANDERER wrote:
Cutting to the chase...
The 3 cell battery offers more cycles and can take more abuse.

pretty simple. two 3 cell batteries = one big 12v that should last if cared for.

[placergold]

Now I know, thanks ktmrfs!

[ktmrfs]

placergold wrote:
Thanks you all for the feedback!
2oldman: light reading not, LOL!
MEXICOWANDERER: I'll look in to the 3 cell batteries. Anyone else recommend them?

3 cell battery AKA GC, AKA 6V AKA Golf cart. Lead acid batteries are made up of cells that each produce 2V nominal. You can buy 2V, 6V, 8V, and 12V batteries very easily. All are reasonably common.

6V and 12V are probably what most people think of.

[ktmrfs]

wa8yxm wrote:
What is so special about six volt batteries might be a better question.

SO, I will try to present the answer and why I recommend them.

Six Volt (GC-2) style batteries are designed for Golf Car (hence the GC designation) use, which is a long slow (Compared to total capacity) discharge to a level as low as 50 percent state of charge.

They are also the single. MOST PRODUCED Lead acid battery in the US and likely the world as golf courses order 'em by, depending on the course, the pallet load or the truck load.. Now that's a lot of batteries Each golf car takes at least six.

RV use is the same, a long slow discharge (Compared to total capacity)


NOw starting batteries on the other hand are designed to dump current at 2 or 3 or more times their C/20 capacity rate (I will explain) But only for 30 seconds, THey need to be kept fairly full, like 80% or more state of charge This means there is not a lot of power to use.

MARINE/deep cycle can go a bit lower, say 75% but that's still only half the DEEP CYCLE GC-2

Finally capacities

C/20 means the 20 hour capacity if you discharge the battery so it hits DEAD exactly 20 hours from start, HOW many amps did you use... Times 20
Understand not all companies rate their batteries that way Wal*Mart for example uses the 1 amp rate.. This gives their batteries a much LARGER number when in fact.. they are not any better than others.

Capacities
Group 24 is about 75 AH at the C-20 rate
Groups 27 and 29 are just below and above 100
Group 31 is about 120-130
"
But these are MARINE/deep cycle so you can use 25%

Now. the CG-2 is 210-230 and you can use half of that.

I mentioned earlier the it is the single most popular lead acid battery.
Well that means the production lines do not shut down and re-tool as often so the unit cost is far smaller per unit due to the cost of re-tooling frequently to make different sizes.

Now you have the reason I LIke GC-2 Most BANG for your BUCK.

I'll add that for most RV uses, even heavy boondocking, safe discharge levels for a quality GC2 is down to 25 percent SOC, Trojan T125 will give around 500+ such charge discharge cycles before going to 75 percent of spec'd capacity. Discharge to 50 percent, and the number of cycles is well above 1000.

So, for most of us that boondock with GC2, check the mfg spec on discharge cycles. likely you can deeply discharge without damage.

certainly don't worry at all if you occasionally drop them down to 25 percent SOC. Just don't go below that and don't leave them there, get them charged back up ASAP.

I've done that on two sets, one lasted 14 years, the other is 7 years old and going strong. and they regularly get discharged well below 50 percent. less often now that I have solar.

but the downside to GC is high internal resistance, not ideal for heavy draws like a big inverter. There 12V marine are better.

While I agree they are very common, prices vary all over the place. Currently Costco has 200Aish Interstate GC for about $90, but a Trojan T125 goes for double that or more, and a Decka is around $160.

[placergold]

Thanks you all for the feedback!
2oldman: light reading not, LOL!
MEXICOWANDERER: I'll look in to the 3 cell batteries. Anyone else recommend them?
SidecarFlip: "a pair of Battle Born Lithium-Iron-Oxide batteries" are way out of my price range.
Sandia Man: Thank you, "We installed a large, whole house inverter", Q. what size is it? "along with a smaller, 300 watt inverter in our entertainment center that easily runs our 40" hdtv", etc. Q. How/where did you hook this up?
ktmrfs: We dry camp a lot, weeks at a time. "good charger", you mean besides the 4K Onan generator? Keep them fully charged & watered - point well taken! Don't know what kind of converter comes with it, but I'll find out. I had a Progressive Dynamics in my last rig and it was great. I will have to see how any changes might affect the factory 1 year warranty before upgrading.
corvettekent: Like I said, I'll have to see how any of the upgrades will affect the factory warranty. But, I really appreciate the advice from everyone. It sounds pretty unanimous in favor of getting 2ea 6v GC batteries. I think it might be a good idea to monitor everything for a couple months as we travel in the new rig and see what we need, as far as upgrades to meet our usage. One of the posts I read provided by 2oldman (I think?) recommended getting a good high quality battery/charge monitor, great idea! Don't think there should be any warranty issues with doing that.
camperguy99: WFC09855, please explain how to "tweek it up to something like 14 volts"?
wa8yxm: WOW, very informative post!
Q. What do you all think, wet or dry (AGM, ETC.) 6v GC batteries?
jplante4: With a lot of planning we camp in the hills of Baja, Mexico, or on BLM land in the western U.S. for 1 to 3 weeks at a time, then go to town to resupply. We might stay in the same area for a month or two. The rig I sold had 2ea 12V sealed Interstate batteries, a 200 watt roof solar panel, and a generator. We would use small inverters for our sat device, cell phones, etc. This simple setup worked well for many years.

[Bill_Satellite]

placergold wrote:
Hi all, While waiting for our new 28' Stealth toy hauler we're trying to figure out the best batteries to get for when we're back in the hills camped off the grid.

We ordered the optional 200 watt solar panel & regulator with Power Boost. And a 1,500 watt Go Power Inverter.

I've been told the golf cart type 6 volt batteries will last much longer than the 12 volt deep cycle batteries available. Mainly because of the constant discharge/charge cycle that occurs.

But, I really have no experience in this area, so any and all input from those familiar with this subject would be greatly appreciated!

Thank you.

No difference 12v or 6V. You just need total Amp Hours. 2 6V that provide a 60 AH rating will provide the exact same output as 1 12V battery that provides a 60 AH rating.