Community Forums

gorgill · 11-14-2011, 06:35 AM

I am about to changing my coach batteries (Currently 2 12s in parallel) and am thinking about 2 6 volt Deep cycle interstates in series. I have been told that I should think about going to 2 6 volt batteries for coach. Is it better to use Deep cycle 6 Volt Golf Cart Batteries? Also I dont think I want a Deep Cycle for the cranking battery. Any help will be appreciated.

Thanks,

confused

Ed-Sommers · 11-14-2011, 08:50 AM

Your thinking is correct. True Deep cycle is used in coach batts because a low amp, long period is what they are designed for, and charging is done in a like manner.

A starting batt needs to provide a very high, starter amperage, but for a short period. Charging is provided in higher amperage, again just like the discharge!

While a high charge amperage to house batts will ruin them, a start batt will, to some degree, tolerate charging at a lower amperage than designed for.

Ed

BryanL · 11-14-2011, 10:15 AM

Do not fall for the 'deep cycle' or '6v golf cart' battery myths!

If you look at specifications and warranties and read the various more competent web sites critically, you'll find that the differences between batteries available at common retail for RVers (yes, I have to qualify like this because of the whiplash from those who hold to their myths) are so small compared to inherent variabilities with lead acid batteries as to be irrelevant.

When you look for new batteries, find a retailer who sells a lot to folks who use batteries like you do and stands behind what he sells. Then use specifications, cost, and warranty to guide your purchase.

The stuff about 'deep cycle' and low amps and such might have had some validity a century ago but is not the case with modern lead acid batteries of the sort most of us use and buy.

Also, if you look at the causes for battery death or if you do an analysis of cycle utilization in RV service, you'll find that deep cycling isn't an issue for typical RV use.

For best battery life, put your efforts on a converter and charger that does multiple stage charging and has a battery storage maintenance mode featuring a sulfation ihibiting technique. Avoid abuse such as high temperatures, excessive discharging, and sitting around without a full charge.

Perry White · 11-14-2011, 10:20 AM

BryanL's right. Also check the dates on the batteries you are buying. Some batteries on Sam's shelf has an '09 date. Esp the 31 series.

JimM68 · 11-14-2011, 12:01 PM

The posts above do bring out some thought....

In my first moho, someone somewhere decided to put a single cheap interstate car battery on the house battery shelf. It was a no brainer to go to the golf cart store 2 blocks from home and buy a pair of trojan t105's. They fit, and comprared , they worked really well.

As for the charging amps, our current knight came with six volt interstates and a 100 amp inveter/charger and 4 interstate 6 volt batteries.

So far at least it all works ok. In my limited boondocetking experience, I've had to run the genny for a charge twice a day.
Guess I need to get better at boondoking?

paz · 11-14-2011, 04:24 PM

Quote:

Originally Posted by BryanL

...read the various more competent web sites critically...

Any chance you could provide links?

BryanL · 11-14-2011, 09:45 PM

for links, see Understanding batteries, start with these links -- it's a few years old and will probably have some lost links but otherwise should be a good start.

paz · 11-15-2011, 05:54 AM

Quote:

Originally Posted by BryanL

for links, see Understanding batteries, start with these links -- it's a few years old and will probably have some lost links but otherwise should be a good start.

Thanks. I haven't had time to go through it all, but there is lots of good info there.

gorgill · 11-15-2011, 06:53 AM

Thanks for the info, I appreciate it.

wa8yxm · 11-15-2011, 10:56 AM

For starting use the manufacturer's recommended battery (Staring type)

For the house.. Deep cycle v/s golf car. I believe Golf Car batteries *ARE* Deep cycle.

(That one is thus equal) The advantage of the battery types.

Pound for pound they all contain about the same amount of energy (Amp hours) However STARTING batteries are designed to be kind of a "Flash in the pan" To give up that energy very swiftly, thus a 75 amp hour starting battery can deliver 150 amps or more (Quite a bit more in fact) in fact I've seen batteries with less than a 30 amp hour rating which could deliver 1,000 peak amps.

However they are sensitive to being discharged too far. If you run them down (Say the Alternator fails) you can find yourself buying a new one after just one or two OPPS.

DEEP cycle batteries, on the other hand, are not as good at very fast discharge... But they don't object AS STRONGLY to an "OPPS, I should have recharged yesterday"

(This is not to say they do not object,, Just not as strongly)

captaindesmo · 11-16-2011, 09:34 PM

This seems like a good place to put a question, my 92 Bounder has a two year old Optima red top and two 6v deepcycle. When I bought it I drove it 100mi. home and several days later it started fine. I think I left the battery switches on (hard to tell, they have no off/on position or lights) and the battery went dead. I trickle charged it to 12.7v. batteries off, three days later 9.7v, pit charger on it again. this is not a normal drop/time period? theMH has a history of sitting long periods (92 w/19,000mi). Do I have a shot battery, or power drain somewhere even with switches off do these switches ever fail to disconnect completely. if it is battery will it recover after being charged a few times? I will check it tomorrow and I think it will show 12.7. How long should it continue to show 12.7