6v GC batteries vs cheap 12v sorta deep cycle

[Snowman9000]

The more I learn, the less I know.
🙂

Or, a little bit of knowledge is dangerous.

So I am wondering if GC batteries are truly better than cheap "Marine/Deep Cycle" Group 27's or 31's for everyone with a typical two battery RV setup. And I'm ignoring availability and redundancy benefits of the 12's. Just cost and battery life.

As a personal note, I have had 2xGC in both of my last two fivers, actually the same batteries moved from the first to the second, and they seem to be in great shape. But they are on shore power with a PD converter, so who knows.

GC's have thicker plates. That makes them more able to survive deeper discharges, and more of them. It also makes them dislike and resist faster charging rates.

If you have solar or often have shore power, it seems that GC's should last longer. But if you do a lot of camping with generator recharging:
A) can the thinner plate 12v's be charged faster, saving you gas, and
B) do the partial charges kill the GC batteries soon enough that their longer life advantage doesn't happen?

Just questions. I have no agenda.

[ktmrfs]

Are GC better????

Well, like so many things depends on what YOUR needs are. For some applications yes, for others maybe, and for some IMHO they are NOT better.

Nice thing about GC batteries is that with the huge number of golfers, there is a high demand for GC batteries, which keeps prices down, availability up. BTW they are used in more than golf carts, also floor machines etc. And the technology and construction is very similar if not idenical to L-16 and other 6V deep discharge batteries used in fork lifts etc. Decades of development to optimize the typical use, which happens IMHO to be pretty similar to SOME RV'rs use and needs.

And they match up quite well with many of the needs/requirements of us "dry campers".

That said, IMHO they aren't necessariy the "best" choice for everyone. if you seldom dry camp, or do so only for a night or so before getting to power, or have high draw inverters, then 12V battery(s) could well be a better fit for your use. For those who seldom dry camp, camp only a few days/weeks/year a decent 12V may be more cost effective in the long run.

If high draw stuff is your primary need (microwaves etc.) with 75+ amps, then again, GC may not be a good choice. to much voltage drop. Likely would be more satisfied with a true 12V deep discharge setup.

My experience is that GC shine with lower draws (<50A, or even 25A) and when you really want the most "useable" AH and decent cycle life and needs are more than a few weeks/year. Hundreds of cycles even when going down to 20-30% SOC.

A 240AH 12V bank dischaged to 50% (the usual recomened minimum for 12V) yields 120 "useable" AH.

the same 240 AH pair of GC discharged to 30% SOC (20% is the recomended minimum from trojan, and even then cycle life is about 200 cycles to 50% of Initial capacity, about the same as trojan 12V true deep discharge batteries discharge to 50%) is 170AH, That "extra" 50A can mean a LOT when you need it. And occasionally going to 20% SOC is pushing 200 "useable" AH

GC happen to fit our bill pretty well. Dry camp probably 60 days/year, other than occasionaly draws of 80A for a few minutes with the microwave our draw is moderate. But we camp in the spring/fall and often want to use the furnace in the morning as well, and I want to go 5+ days between charging if I can with only some moderate solar for the times the sun shines.

so far I get over 8 years from a pair of GC even with regular pretty deep discharges. Just keep them watered AND periodically taken to a FULL 100% charge.

[wa8yxm]

One question: Have you compaired the price.

First: As you noted, Golf Car (CG-2) batteries are true deep cycle (Thicker plates, different chemistry) and thus better able to handle deep and I mean "OH CRAP!!! level deep discharges.

Marine/deep cycle, not nearly that good.

Second... They are not all that expensive. price 'em at Sam's or Costco.
Price on six volt's is close to group 24 pricing, Group 24 are about 74 amp hours each (150 per pair) GC-2 in series, 230, that's better than 3 G-24's in parallel. So they are often cheaper.

For the person who claimed that DEEP CYCLE means as much as the "Extra Heavy Duty" Hype you see on so much.

Deep Cycle means different plate construction and chemistry It really does have meaning, it means the battery is designed to take a discharge down to 50 percent over and over, not 75-80 percent like starting (including marine/deep cycle) batteries.

Deep cycle is only meaningless if preceeded by marine/

[Snowman9000]

Interesting info, thanks.

[BFL13]

I have done it with both types (6s and 27DC) doing 50-90s for several days in a row (five or six 50-90s in fourteen days was the longest.) While camping they perform the same per AH capacity for draw and for recharging to 90%.

The difference is when you get home and try to get them back to 100% SOC before they go on Float. It is agony trying to get those 27DCs back to 100% using the required "top charge." They don't gas much and take a long time and it is just a huge PITA.

The 6s OTOH, charge right up and take a shot of Equalize on the VEC1093DBD, and it's all done. So simple!

That was it for me, no more 27DCs ever. I have not got any experience yet on that "recovery" aspect with my used true deep cycle 12v golf car batts (T-1275s) I just got for free and dished up, now trying them out while camping. I hope they are not a PITA too like those 27DCs.

[full_mosey]

Matt_Colie wrote:

...
Golf Cart batteries are built to purpose. As many go to courses and clubs that actually keep records, ...

I would like to see one of those logs.

If 6V GCs are designed for golf carts, do these golf carts run hard for two days and then sit in the barn on a charger for five days? Perfect formula for a weekend camper.

Cycles are important as well. By reading Trojan T-105 specs, a weekend camper might get 1200cycles / 50 = 24 years of service by camping every weekend and recharging the other five days. 🙂

Camping style should dictate battery type.

Who wants a battery that lasts a long time, but doesn't get the job done?

HTH;
John

[Matt_Colie]

Snow,

First thing you have to understand is that "Deep Cycle" has all real the value of "Extra Heavy Duty" or "New and Improved". In short, it doesn't actually mean anything. Many of the 12V batteries that are sold as deep cycle are the same as everything else that came off that line, but with a different label, a higher price and lower electrolyte density (that sort of makes them deep cycle - right?).

Golf Cart batteries are built to purpose. As many go to courses and clubs that actually keep records, if they didn't perform (at least when new) they would get them back, and if they didn't last as they were expected, that would be the last that they sold to that shop.

Then there is the issue of paralleling batteries. I won't go there now, I don't have the time. Just believe me when I say it is not the best plan.

I have seen GC's get to be quite old in RV and yacht service. If taken only moderate care of, they just seem to keep on going. Just add water every couple of months. With the heat this year, ours took a beating and seem to be no worse off for it.

Matt

[westend]

On average, for expected use/abuse, a GC2 6V should outlast a cheap 12V, IMO. This assumes the user has adequate charging capabilities.

On your last question: I've found that 6V batteries are more tolerant of discharge and charging miscues than 12V.