Battery Discharge

[ron buckner]

I have a '96 33ft. Airstream Land yacht thats been giving me a bit of problem lately. We just replaced all the batteries (2- Group 27 marine batteries for house and 1- Group 24 for the automotive), 14 months ago. I stored it at our storage lot (no power) for about 5 months and we then took 97 girls scouts and theiir parents out and had a great time with no issues what so ever. (Started right up). After that we brought the coach back to the house and I hooked it into the house (30 amp service) and I periodically checked it (started it uo approximately every two weeks w/no problems). Now, (6 weeks later) I'm getting ready to take GS out again and yesturday the battery was dead. I jumped it and it started right up, let it run for about 20 minutes and the battery has stayed charged. Originally i thought the converter probably boiled the battery, but then why would it take the charge? I'm thinking there must be some small short somewhere, but everything seems to be working. Any ideas?

[Mickey]

OK, are you just talking about the chassis battery being drained? If yes, there are a couple things to think about.

* There is no assurance that the charger/converter charges the chassis battery. More typ they only charge the house battery(s).

* What kind of voltage reading have you taken? What is chassis battery voltage when engine is not running and not plugged into shore power? Is there any change in voltage with just shore power is connected? This will tell you whether charger/converter charges the chassis battery. What is voltage when engine is running?

* What is output voltage from charger/converter? Can't "boil" battery dry if voltage doesn't exceed 31.8V and would take a LONG time if voltage wee as high as 14.25. I'd start to get a little concerned if voltage exceeds 14.25.

* There are parasitic current draws on both the chassis and house batteries from all the various electronic items that need to be powered even when things are shut down. One always needs to address that when rigs are left sitting for considerable time.

* If all checks out OK with the voltage measurements, you may have a bad battery.

[ron buckner]

Mickey,
*"There is no assurance that the charger/converter charges the chassis battery". This was my thinking also. The house batteries are up and all the connected stuff (-RV Ref.) is working fine
*Charge voltage to the house battery 13.9 v @ 2.5 amps. Also, there is a solar charger 10 watt panel. And we had no current registered at the Chassis battery whatsover when the battery was dead (which confused me!)
* I thought a fully charged battery could be boiled out by simply supplying charge with no load to serve. I'd heard that 31.8 v was the max charge most batteries could be charged at before causing boiling, but any charge (say 1/2 amp) above 13.6 volts applied to a fully charged battery could do the same thing too a lesser degree over time (in this case 5 weeks).
*"Parasitic draws" - I agree, but why would it be OK in a lot totally shut down w/no power for months, and then give me issues after only 5 weeks hooked into shore power?
* And then take a jump and charge afterwards?

Now here's another issue. The new battery (sold to me by a reputable RV service company I trust) is SERVICE FREE and states that by breaking the seal on the battery I will void the warrantee. In that it did take the charge I'm pretty convinced it's ok. And I've sinced disconnected the ground to insure the batterry stays charged befroe leaving for this weekend, but I can't check the water levels. It's gotta be in the converter somewhere doesn't it?

[thewiz]

As Mickey said, the converter usually charges the house batteries but does not charge the starter battery.
You might have a bad connection on the starter battery and that made you think the battery was dead?
You might put a switch on the battery to disconnect it when away.
There are some that attach to the battery terminal. Some are knife types and there are screw types.
I put a screw type on our last rv.
There are small drains on the starter battery like the radio memory.
When you have it parked and everything turned off do you draw a spark from the starter battery when disconnecting the lead?
You can use the amps setting on your multimeter and see if there are small loads drawing small amounts of amperage which will draw down the battery over time.

[Mickey]

Ron, a couple comments.

* 13.9V @ 2.5 A is about what one would expect at that voltage. A nom 12V LA battery can rise to ~13.8-13.9 volts and remain there for considerable time without any damage. I wouldn't be too concerned about it.

* You didn't say directly where the solar panel is connected. If connected to the chassis battery and no power is present during the day, possibly either the panel or controller is bad.

* If the chassis battery is not being charged any when parked and when you started the engine a few times & left running for a short period, you were likely taking a fair amount of energy from the battery along with the parasitic draws and finally battery got to the point of not enough energy to start the engine. You do need to try and measure current drain when rig is just sitting. May help explain why the battery was down.

* Last item, LA batteries don't like to be left in a partial/full discharged state. Will greatly shorten the life.

[drifter]

The converter is fine.

You were keeping the starting battery charged when the RV was stored by cranking up the engine every week or so. Leaving it for 5 weeks was too long and the normal small parasite drains pulled the battery down.

Lost of RV's have no method of keeping the starting battery charged up other than the alternator. It's not necessarily a good set-up but that's the way they are.

A little gadget called a Trik-L-Start is a good idea:
http://www.lslproducts.com/TLSPage.html

It only costs fifty bucks and installation is really easy.

[ron buckner]

Drifter, I think your right.
I simply disconnected the ground off the Chassis battery while I had the coach hooked up and let it sit. Taking 63 girl scouts, their parents and siblings up to Kerrville this weekend and it fired right up. I'll be checking on that Trik L Start when I get back, Thanks for your help guys

[Russ Chastain]

You sure can fit a lot of girl scouts in your RV! 97 one time, 63 the next. They must be pretty small... you sure they're not Brownies?

[ron buckner]

We use the RV as a "Home Base". Surprizingly, We've found that having an RV along has made a big difference with comfort zones and young mom's who've never been camping before. I was a BSA scoutmaster (and I'm still a UC here in San Antonio) so "real" out door camping is something I know quite a bit about. Be ing Prepared is what it's all about, and thats what we teach. Getting a Mom or young Dad to be comfortable out in the woods is turning into almost a "calling for us. Obviously they don't stay inside. but the toilet is always clean, and available until the comfort zone is established. Surprizingly, once they've had a chance to spend a successful night in tent, they rarely want anything to do with the motorhome (even the Mom's). Of course we almost always dry camp and I wont use the AC unless I have to for an over-heat emergency. The whole point is self sufficiency. The real surprise is how many Mom's and Dad's have never camped before, I'm from the Pac. N.W. and the Texas climate is a walk in the park compared to the rain and wind up there, I guess camping is just not a priority. Oh, and my wife and daughter want you to know we have all sizes from Daisies on up to Seniors. They run their Girl Scout troop like a Boy Scout Troop. The outing was a total success with 113 total in attendance, and we stayed at "By the River" RV park in Kerrville, it was absolutely fantastic, the kids were in water all day and for an entry level camping experiance the parents had a great time.

[Russ Chastain]

Sure sounds like a great trip, and that you have come up with a great method!

[siberian]

Love Kerrville, especially Buzzy's B B Que. Del Norte was a great place for breakfast.