Why 6 volt golf over 12 volt sealed AGM batteries?

[4x4chvy]

I'm curious.
So many people either start with the 6 volt golf or seem to swap out sealed AGM's for the Trojans. WHY?
Is it simply the lower cost vs. higher amp hour ratio?
Seems to me the easy, maintenance free, safe-to-use-inside, spill proof AGM's would be better, no?
They're supposed to have a longer lifespan than the golf batts.
Please everyone, advise. Thx.

(My v-nose CT doesn't have much room on the tongue for a box, which also leans me towards the AGM's.)

[emiller]

2-Golf cart 6 volt batteries have double the capacity of 1-12 volt. That is why golf carts have 6 volt instead of 12 volt batteries. I use 1-12 volt Lifeline 105 amp hour in my trailer.

[Shadow Catcher]

There appears to be no benefit to 6V golf cart batteries and in reality there seems to be no real difference because you can find AGM as well as flooded cell conventional in what ever size/capacity you want, and the care and feeding of an AGM is a god bit simpler i.e. you do not have to water them as they are recombinant.

http://www.windsun.com/Batteries/Battery_FAQ.htm

[48Rob]

Golf cart batteries are longer lasting, and are less prone to failure from too deep a discharge.
Lead acid batteries are better able to withstand shock (bouncing in a trailer/RV).
They offer more plate surface area (2 large batteries versus 1 battery that produces the same amount of power...)
They are also much cheaper than AGM batteries.

AGM's however, can be recharged at nearly 100 percent amperage, where golf cart sets require a slower, lower amp charger (takes longer to charge).
AGM's self discharge at a lower rate than lead acid batteries (good for intermittant use; i.e. having a fully charged battery when you need it)

AGM's are good, but spendy.

Just a parting note, 2-6 Volt - T105 golf cart batteries (105 Amp hours) wired in series to produce 12 Volts, is still just 105 Amp hours, not 210.

Rob

[len19070]

I have converted numerous battery systems over to 2 6V golf cart batteries.

Mainly because the coach has had an inverter...A BIG inverter, 2000W+.

And these batteries really get beat up.

I have seen some last as long as 6-7-8 years with absolutely brutal use.

Many of my customers don't even know where or what a battery is! And despite the lack of any maintenance what so ever the perform very well.

Happy Trails

Len

[Engineer Guy]

Rob summarizes it well above. The Site linked above, along with info on Big Rig Sites, echo the position that Golf Cart Batteries last longer. It's difficult, to impossible, to charge 2 - +12 VDC Batteries in parallel at identical rates. So, this is thought to cause premature failure of 1 Battery. This is not the case with series-connected +6 VDC Batteries. Plenty of info out there on this...

As you can see on commercial Battery Boxes, not a lot of vent area is req'd. You could enclose Batteries and vent them to the outside, while also providing a bottom vent for fresh air to convect up through passively. I would caulk the seams of whatever enclosure you build to prevent fume leakage. A gasketed lid would seal in fumes while allowing access. Others will weigh in on this technique, no doubt...

[fromeo]

I agree with the above, with only one minor exception - the T-105's are rated 225 Amp hours (20 hr rate - http://www.trojanbattery.com/Products/T-1056V.aspx.

In my opinion, for the money, it's hard to beat a golf cart battery. When it comes to a lead-acid battery, weight is king in the durability department. The plates on a GC are thicker and solid. In comparison, a "starting" battery (AKA "SLI") has thinner, perforated plates. The perforated plates are used to increase surface area which is what gives a starting battery it's "cranking amps."

GCs are readily available, you can pick them up at any Sams Club or Costco. GCs are also a sure bet as far as them being true deep cycle. It can be very difficult to find a true deep cycle in 12V, many wind up being constructed just like starting batteries. GCs also enjoy a great reputation with many people reporting 10-12 years lifespan.

AGMs are cool stuff. They still should be vented for safety as they can vent if accidentally overcharged. They do have different charging requirements than a wet battery, so for best life you should ensure that your charger is suitable for AGMs. A couple on another forum I frequent are full timers and love their AGMs, I believe they run Lifelines (they have a lot of info on their rig on their site http://www.everymilesamemory.com/). I have never heard a bad report on Lifelines, and if I was in the market for an AGM I'd start with them. On the other hand, I wouldn't take another Optima if it was given to me for free (yes, my experiences have been THAT bad).

On my trailer I run 4 Energizer branded (mfg. by Johnson Controls) GC2s from Sams Club. These are rated at 220Ah and sell for (as I recall) about $70/ea. I'm going into the third year with these, and I'm very pleased with their performance. We enjoy dry camping, and with 440Ah on board, it's a real pleasure. I do water them on average twice a year, and stick a hydrometer in them on occasion to make sure things are OK. So far, so good - I wouldn't think twice about running them in the future:



- Frank

[emiller]

Maybe this gives some insight.
Amp-Hour Capacity

All deep cycle batteries are rated in amp-hours. An amp-hour is one amp for one hour, or 10 amps for 1/10 of an hour and so forth. It is amps x hours. If you have something that pulls 20 amps, and you use it for 20 minutes, then the amp-hours used would be 20 (amps) x .333 (hours), or 6.67 AH. The generally accepted AH rating time period for batteries used in solar electric and backup power systems (and for nearly all deep cycle batteries) is the "20 hour rate". (Some, such as the Concorde AGM, use the 24 hour rate, which is probably a better real-world rating). This means that it is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours it supplies is measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications. The 6-hour rate is often used for industrial batteries, as that is a typical daily duty cycle. Sometimes the 100 hour rate is given just to make the battery look better than it really is, but it is also useful for figuring battery capacity for long-term backup amp-hour requirements.
Why amp-hours are specified at a particular rate:

Because of something called the Peukert Effect. The Peukert value is directly related to the internal resistance of the battery. The higher the internal resistance, the higher the losses while charging and discharging, especially at higher currents. This means that the faster a battery is used (discharged), the LOWER the AH capacity. Conversely, if it is drained slower, the AH capacity is higher. This is important because some manufacturers and vendors have chosen to rate their batteries at the 100 hour rate - which makes them look a lot better than they really are. Here are some typical battery capacities from the manufacturers data sheets:
Battery Type 100 hour rate 20 hour rate 8
Trojan T-105 250 AH 225 AH n/a
US Battery 2200 n/a 225 AH 181 AH
Concorde PVX-6220 255 AH 221 AH 183 AH
Surrette S-460 (L-16) 429 AH 344 AH 282 AH
Trojan L-16 400 AH 360 AH n/a
Surrette CS-25-PS 974 AH 779 AH 639 AH

[Trackstriper]

It's difficult, to impossible, to charge 2 - +12 VDC Batteries in parallel at identical rates. So, this is thought to cause premature failure of 1 Battery. This is not the case with series-connected +6 VDC Batteries. Plenty of info out there on this...

Probably the fewer cells used in the total system the better. There are some pretty good sized 6-volt AGM batteries available if you have the coin. Better than running multiple 12-volt batteries in parallel.

[bdosborn]

There appears to be no benefit to 6V golf cart batteries <snip>

Well there's one huge benefit. Golf cart batteries have the lowest $/amp-hr. You just have to be willing to water and vent your batteries. I have a pair of reconditioned golf cart batteries that are going on the 3rd season of use. I paid $40/battery for 220 amp-hrs of capacity.

Bruce

[H-Balm]

Have a site with golf battery info and maintenance care, by chance?

Never worked with a non-automotive battery.

[Engineer Guy]

I was reading up on this last night after perusing this Topic in this Forum. Deka brand is highly thought of, and I can get them locally at a Farm/Truck Supply place. My own 'technique' is to look at suggestions from various Manufacturers, and at independent info from Solar/Off Grid folks. Combine all that info into a personal viewpoint... GC Batteries can withstand very deep discharges, and are built to tolerate vibration.

One fellow said he waters his GC Batteries 2x/yr., and performs a Hygrometer check then. Not too demanding a maintenance schedule...

Deka Golf Cart Battery Maintenance

Deka Golf Cart Batteries

[bdosborn]

I like this guys page, its probably more than you need:

http://www.marxrv.com/12volt/12volt.htm

Bruce

[4x4chvy]

*Engineer Guy* said:
"GC Batteries are built to tolerate vibration."
That statement sold me on GC batts. My CT and my truck spend quite a lot of time off-road and on poor dirt roads.

I have juuuust enough room on my trailer tongue to mount two GC's in a dual batt box. No worries about them gassing inside or being near the propane. Cool!

Are Sam's club/Costco batteries as good as Trojans to the point it's worth spending the extra $$??? Or are the Sam's/Costco CG batts good enough?

[bdosborn]

The loose consensus at RV.net is that Trojans are clearly the best but recent price increases have priced them out of the running against Costco/Sams club etc. I haven't looked at prices for awhile but Trojans were 50% higher when I last looked. Its too bad, they weren't that much more expensive 5 years ago but they had a change in management and the prices skyrocketed. A lot of places don't carry them anymore because of that.



RV.net Clicky

Bruce