Community Forums

Wanabee FTer · 10-02-2010, 11:02 AM

Seems like everyone has at least 4-6 volt golf cart batteries for boon docking.
Wondering if anyone boon docks with 2-12 volts and what kind of feedback good or bad?

BryanL · 10-02-2010, 12:21 PM

There must be something in the water that correlates buying batteries by other than sound measure and the tendency to brag about it .... ;-)

What you get in RV batteries is about 10 to 15 usable watt hours per pound of battery. The voltage or marketing hype that goes with the battery is insignificant (just look at the specs).

The life of the battery has more to do with how you use and maintain it than anything else. Again, marketing hype such as 'golf cart' or 'deep cycle' make little or no difference (see the NAWS FAQ) compared to proper use and maintenance.

From what I can tell, double 12v is most common in original RV equipment of moderate size (i.e. most trailers).

Feedback is nice but the number of variables involved mean that it will be extremely difficult to control for voltage alone. The nominal variance due to things such as temperature, use profile, age, and cycle to cycle variance (more than 10% for each) mean that you would need large sample sizes to gain any reliable measure.

So, take your pick. Use the measurements manufacturers and retailers will stand behind or depend upon the folks around here who have impressions and like to brag about them. It probably isn't going to make much of a difference one way or the other as most of the results will end up depending upon your own particular circumstances.

deandec · 10-02-2010, 02:48 PM

Yes, I have used two Group 8D 12v deep cycle storage batteries that came originally with the coach. They provided 220 Amp Hrs each or 440 AH combined.

I replaced those batteries with 4 six volt Golf cart batteries that provide 450 Amp Hours.

The 4 six volt golf cart batteries totaled $350. That is a little more than one 12V 8D battery would have cost.

safari1 · 10-02-2010, 03:21 PM

I use 2 Blue top Optima batteries, love them. I will only use AGM batteries in the heat of AZ, wet cell only last a short time here.

Wanabee FTer · 10-02-2010, 05:29 PM

Quote:

Originally Posted by deandec

Yes, I have used two Group 8D 12v deep cycle storage batteries that came originally with the coach. They provided 220 Amp Hrs each or 440 AH combined.

I replaced those batteries with 4 six volt Golf cart batteries that provide 450 Amp Hours.

It sounds like the 8D's were almost the same AH rating compared to the golf cart batteries. Is there a noticeable difference between the 4-6 volt and 2-12 volt set up you had.

Gary RVRoamer · 10-02-2010, 08:05 PM

Two car battery size 12v (as opposed to the huge 8D's) will only produce 170-210 amp hours, so that's about half the power of 4 x 6v. A Group 24 12v is about 85 AH and a Group 27 about 100-105 AH.

With two standard 12v batteries, you are probably good for one night if it is chilly (furnace use) and two full days if no heating is needed. It all depends on how conservative you are, though.

Wanabee FTer · 10-02-2010, 08:12 PM

Thanks Gary,
That's pretty much what I was looking for. I have 2 new 12 volt deep cycle batteries for a total of 164 amp hours, mighty slim compared to 4 GC batteries, but absolutely no room for 4 batts. As long as I can make it through one night using the furnace while conserving as much as possible I should be alright.

deandec · 10-03-2010, 11:18 AM

Quote:

Originally Posted by Wanabee FTer

It sounds like the 8D's were almost the same AH rating compared to the golf cart batteries. Is there a noticeable difference between the 4-6 volt and 2-12 volt set up you had.

No useage differences noted. The GC batteries require less space than the 8D and are easier to load and unload since the 8D is over 100 lbs per battery.

The 8D batteries lasted about 9 years (the first seven years the rig was not used much), the Golf Carts lasted 6 years with routine use and abuse.

RJay · 10-03-2010, 11:57 AM

Some time you have to buy the batteries based how much room you have in your battery compartment and that may be 2 - 12 volt group 31's vs 2 - 6 volt group 105's.

deandec · 10-03-2010, 12:09 PM

If space is a problem for more than 2 batteries, then two 6v golf cart batteries providing 225 amp hours of 12v service would just be reduced to a cost/benefit decision.

az bound · 10-03-2010, 03:20 PM

I use 2-12vt. 245AH AGM batteries.

Gary RVRoamer · 10-04-2010, 07:15 AM

You can probably fit in slightly larger batteries in that space for two. If two GC2 golf cart batteries will fit, you can get 220 AH in the space you now have 164. Or substitute a Group 27 size 12v for your Group 24's and get about 210 AH. That's almost 40% more power.

Wanabee FTer · 10-04-2010, 10:41 AM

Thanks for the reply,
When I purchased the coach a few months ago it already had new coach batteries. It looks like the battery tray could hold 2 group 31's, but only has 2 group 24's now. I will use these for a while and if they are not adequate I will replace with 2-6 volts and rewire in series.

leadman · 10-05-2010, 07:38 PM

We have 2 group 27 batteries that were in the coach when we bought it a year ago. The thing I did that made the difference in how long the batteries last is installing 4 LED lights inside the coach. These 4 lights draw a total of .6 amps, while 3 of the old incandescants drew 4.6 amps. We normally run only 1 or 2 of the LEDs at a time.
We also installed a small tv/radio/dvd/cd player that is mounted under the kitchen cabinet. Does not draw much power.
If you buy an invertor get one that doesn't draw power when turned off, and uses a minimal amount of power to convert the power. Our first one was a cheapy and was not good. Bought this one from Fry's Electronics and it works great.
Check out my post in Vintage Rvs about the Harbor Freight solar I installed. Not a total replacement for a generator but it does triple the time we can camp without running the generator.