Keeping starting batteries charged during bus storage... solar?

Kevin Warnock · July 03, 2006, 05:36:31 PM

Hello,

I just paid $400 for 2 new 8D Heavy Duty starting batteries. My old set worked fine until I put the bus into storage for 2 1/2 years. I thought I was doing the right thing for long storage, as I filled the diesel tank to capacity. But I didn't know about the battery problem. I was told at the battery store that I had ruined the batteries by the long storage. I did take them out of the bus and charged them at 2amps for 72 hours. They were bubbling and slightly warm at the end of this charging. But when I installed them, the bus would just weakly make a noise, and got no where near actually starting. With the new batteries, it started immediately with confidence.

I have a Trace C40 charge controller and 100 watts of solar panels at 24 volts for my big house battery bank. They stayed fully charged and seem to be fine after the long storage. I did put water in them a couple of times during storage. The starting batteries never got low on water just sitting there.

I am thinking about putting 2 more solar panels on the roof and getting a separate charge controller for the starting batteries. I don't want to have these new costly batteries die on me, and i like being able to just start the bus without jumping it from the house bank, like I had to do recently. I have 2 - 21watt 12 volt solar panels I never used, so my total cost would be just for the wire and the charge controller, which I can get for about $210 at Backwoods Solar, which, by the way, always has helped me a lot with my questions. I bought my Trace SW4024 from them. I recommend them highly.

What do you think of my plan to keep the starting batteries charged? I take it I should not just join the starting batteries and the house bank during storage, as I take it the charge controller would be confused by trying to charge two banks of different battery types at once. Is that right?

Oh, the bus is in a storage lot where there is no AC hookup.

Thanks!

Beatenbo · July 03, 2006, 06:18:42 PM

www.batterylifesaver.com Works!

Dallas · July 03, 2006, 06:39:30 PM

$400 for 2 8D's??? Wow! I see them here at Sam's Club and Car Quest All the time for anywhere from $88 to $110 each.

Dallas

Kevin Warnock · July 03, 2006, 06:56:43 PM

Quote from: Dallas on July 03, 2006, 06:39:30 PM
$400 for 2 8D's??? Wow! I see them here at Sam's Club and Car Quest All the time for anywhere from $88 to $110 each.

Dallas

Really, $88 to $110 for a heavy duty 8D battery? I paid $183 each before tax, and this was from a large wholesale battery dealer that specializes in big batteries like the Trojan L16 and the 8Ds. They had racks and racks of batteries in stock, and the 8Ds were in stock and charged. They lifted them into place for me and I hooked them up. I feel awful that I paid double what they are available elsewhere for. Note that I am in San Francisco, so maybe that explains some of the price difference?

What have others paid for 8Ds, may I ask?

I doubt I could return them, but if I went in mad on Thursday morning, maybe they might knock some money off the price I paid.

Thanks

DrivingMissLazy · July 03, 2006, 08:19:41 PM

I really suspect that 2 amps for 72 hours is like spitting on a fire! This is assuming they were completely dead.I would think that you would have have to have at least 20 amps for the two batteries, if not more. for at least 24-48 hours.
Richard

Dallas · July 04, 2006, 12:57:25 AM

I think I have to agree with Richard on the 2 amp charge rate.
I misread it the first time and thought it said 20A.
It might also serve you well to get a good hydrometer or even better a refractometer to test the specific gravity of EACH cell before and after charging.
Another thought, after they are charged, puchase a load tester (about $20) and see what they really are capable of.

You also might want to invest in a battery dissconnect switch in order to make sure the batteries aren't being frained by 'phantom' loads, like the clock on the radio or a bay light swich that doesn't shut off.

Stilll, Dammee! For $400 I'd have replaced the 2 8D's with 2 group 31's ($60-$80 each), especially if you no longer run the Coach factory A/C. They are lot's easier to move around and have around 1000 CCA as compared to the 8D's 1150 CCA.

Then you would have enough left over for a couple or 24 adult beverages to partakee of and and the ability to sit back and contemplate a job well done!

Dallas

Stan · July 04, 2006, 07:09:11 AM

I agree with the others on price of 8Ds. You will never know if your old batteries were still useable and a store that overcharges would not be above giving bad advice in order to make a sale.

Back to the original question. Your idea of a a good solar charging system may work OK. I have had no problem letting batteries sit for six months in cool/cold weather and still start the engine. Sitting in hot weather increases the self discharge rate and some form of charging is required. Sitting for two and a half years is another question. I would consider that to be approaching the normal life expectancy of cheap (ordinary lead acid) starting batteries and just plan on buying two new 8Ds for $100. each. If they were relatively new batteries, I would try and sell them before storing the bus.

Len Silva · July 04, 2006, 07:23:35 AM

Just think of all the money you saved by filling the tank 2-1/2 years ago. What a good investment that was.

Len

pvcces · July 04, 2006, 10:35:57 PM

1967_MCI5a, I wouldn't be shy about just connecting a single 21 watt solar panel to both 8Ds, connected in parallel. This would mean that they would get less than one amp each for part of every 24 hours and might require watering once every three months.

Instead of a controller, get a $50 desulfater to leave connected to the batteries while in storage. The desulfaters can be bought to use 12 volt power, so you will not need AC to make it work. Sulfa-Tak and Solargizer come to mind.

Good luck with the solar.

Tom Caffrey
Suncatcher
Ketchikan, Alaska

Beatenbo · July 05, 2006, 11:03:04 AM

8Ds have stayed in the 100-140 range for some time. I have bought them here in the east at Sam's club for 98 each. The last set I bought seems like about 20 more. They normally last 2-3 years. It is no shock with rising prices that some one would charge this for a pair. Ya hav to shop around !

DrivingMissLazy · July 05, 2006, 11:31:55 AM

While living in Southern California I found that I had to disconnect my solar charger when the coach was left sitting for several weeks. Of course, we got a lot of sunshine there also. Even with the automatic controller the batterys would eventuually start overcharging and boiling the batteries. The house batteries were the only ones connected.

Take that with a grain of salt as the solar system was installed in the late 80's so there probably have been some major changes in solar charge controllers over the intervening years.

Richard

David Anderson · July 05, 2006, 02:55:56 PM

You're probably correct about that Richard.

There are some serious solar users on the Escapees.com board.

http://escapees.infopop.cc/eve/ubb.x

They usually post in the "boondocking" section of the board. Some of the guys never hook to a pole. They live like cavemen, admirable in some ways, but a bit too frugal for me and my wife. I bet they have very unstressful lives, however.

David

BJ · July 05, 2006, 08:36:58 PM

Here in Tulsa Sams club batteries arre around $100.00 I went through 3 in 9 months so now I but sears 8D's with a much better warrenty..

Len Silva · July 06, 2006, 04:01:25 AM

I had a problem with Sam's Club batteries being out of date. I broke down in my truck and got a ride to Sam's and bought a new battery. When I got back to the truck and put it in (by now it was past dark:30) it was dead.

Turned out the battery was over two years old. Check the date codes when you buy a battery and if you buy multiples, make sure they are all the same.

Len