Coach Battery SLOW Drain

[Marko Polo]

Electrical Gremlin advice sought!

My coach battery is draining, quite slowly at that. It takes about a full day to drain it to the point the CO detector loses power. The van battery starts/runs no problem, only the coach battery. If you guys have any insight i'd appreciate it, as those dealer labor fees are expensive!

Recently i've done some upgrades - please correct me in my thinking it has to be the refrigerator.
1) New refrigerator installed by dealer.
2) New stereo receiver/speakers
3) Cargo carrier with LED lights and license plate light installed to the back, run through hitch wiring harness.
4) New hitch wiring harness.

Of these four things, wouldn't the refrigerator be the only one to effect the coach battery? The other three all run off the van battery, right? Also, i'm new to the multi-meter, but how would I check if the battery is good and what the pull is on it with everything off?

I've started pulling fuses to leave ONLY the CO detector on, and it still drains the battery in a day or so. So... bad battery? Short? What's pulling the juice?

Thank you for your help!

[skater]

I'd argue that a "full day" is a fast drain, not a slow one!

First, are you sure it's not the battery itself? I would plug in the camper and check the voltage of the coach system. It should be ~13.2 volts or so. If it's much lower than that, the converter is shot and it's time to replace it, and the problem you're having is that the battery simply isn't getting charged (though it'll probably also be bad at this point).

If that's not the answer, you can check the drain by: Charge up the battery. Disconnect the negative. Use a multimeter in current mode (amps) to determine what the drain is. My multimeter doesn't handle more than 10 amps, but I doubt you have anything quite that strong. Then, go to the fuse panel and see what circuits are drawing current, if any - use the multimeter in place of the fuse.

I agree with the possibility is that it's the fridge. Diagnosing it depends on what kind of fridge you have - if it's a new three-way fridge, for example, the 12 volt mode should only work when the engine is running. If you're running it on 12 volts the rest of the time, you'll see a pretty quick drain of the battery like you're experiencing. On the other hand, if the fridge has an electronic board (they all do these days, I think), its 12-volt draw should be minimal while it runs on 120 volt or propane.

[Marko Polo]

Skater -

Thanks for the help - for someone who doesn't even own a B-van anymore you're really solid about helping out with them.

I'll test the pull on the circuits this weekend and see where the problem lies. If it were the converter, would prevent the battery from charging? It wouldn't draw when the van is off. So far every time I drive down the road it charges the battery enough to get the CO detector back on - at least for a few hours.

[skater]

Thanks for the help - for someone who doesn't even own a B-van anymore you're really solid about helping out with them.

Thanks. I did own one for 6 years, and a problem like this is more general to any type of camper.

I'll test the pull on the circuits this weekend and see where the problem lies. If it were the converter, would prevent the battery from charging? It wouldn't draw when the van is off. So far every time I drive down the road it charges the battery enough to get the CO detector back on - at least for a few hours.

Correct - if the converter is bad, it won't charge the battery. That's why I wanted you to test the voltage with the converter running. Plenty of people have had them fail. Mine was down to about 10 volts before I replaced it. It was one of the best upgrades I ever did - I never had to worry about the battery again. I did the same upgrade to our trailer (albeit with three batteries instead of just one) shortly after buying it.

And you're right - as you drive (in most B190s - there seem to be a few that don't have the relay) the alt will charge the coach battery.

[Marko Polo]

Thanks again Skater - might have to press for some more details if I can't figure out the multi-meter once I get it back, but everything you've said makes sense.

Finally got this picture of the build-out uploaded - too large to attach here. The van is at a local welder right now (hence not in my possession) getting stabilization for the locker added. Let me know what you think! I'll try to get some more/better pictures up before we take off this winter.

http://b190.com/gallery2.php?g2_itemId=2816

[skater]

Wow, you actually have a literal locker back there. Interesting!

[Mgittrich]

Marko,

I recently completed upgrading the converter, adding a trimetric monitor and a battery switch in preparation for adding a battery bank ( 1 battery under the couch & 2 batteries under the stove) so I can do more dry camping. When I was making these upgrades I encountered a second 12ga wire connected directly to the positive fuse block along with the positive battery cable connected to the house battery under the hood. This 12ga wire connects directly to the drivers power seat and the refrigerator via a couple of circuit breakers and a relay. See my post on this topic for more information.

http://b190.com/viewtopic.php?f=4&t=1327#p5209

When I wired this 12ga wire to the battery selector switch I wired it directly to the BAT1 side of the switch rather then the OUTPUT post of the switch. This directly mirrored the implementation before the upgrades which would allow the seats and refrigerator to operate even when the battery selector switch was in the off position. Please note the refrigerator 12v operation is controlled by a relay which activates the circuit when the b190 ignition is energized.

The day before I put the b190 into storage I noticed that the battery was drained to less then 11v and the battery selector switch was set to OFF (all circuits connected to the fuse block are disconnected when the battery selector switch is in this position) but the Trimeteric monitor registered a .1 amp drain. I scratched my head a minute and the realized that the 12ga wired connected directly to the BAT1 post was still active and something on this circuit might be the source of the drain. So I disconnected this circuit from the BAT1 post and connected it to the OUTPUT post of the battery selector switch. When I did this the Trimetric monitor did not register a battery drain when the battery selector switch was in the OFF position.

Therefore I believe that the drain was coming from the power seat / refrigerator circuit. Unfortunately I couldn't do anymore analysis on this problem as the b190 went to storage the next morning. I'll pick this up again in April 2014 when it comes out of storage.

I hope this helps you and I certainly would be interested in anything you find out. Let me know if I can be of further assistance.

Mike Gittrich

[Marko Polo]

AIGHT -

Hooked up the multimeter to find the battery has a constant draw of 0.193 on the 10A scale (19.3 milliamps I believe). Which I believe is totally normal. It may be a slightly larger pull than usual due to the new Norcold N300.3 refrigerator, but not overboard.

What is NOT normal, as I learned when I winterized the van the day before, is leaving the water heater on. This bumped the drain way up and would explain the coach battery going dead after a day or two, along with nearly scalding my hand when draining the water heater.

Charged battery fully, re-installed it. Will keep it on observation for a limited time but i'm thinking we can chalk this one up to the ever-growing-list of "I'm An Idiot".

[Kentuckian]

...another lesson learned. And the good news is that you learned it in your driveway and not out in the boondocks! Hope that takes care of your issue.

[Alaskan]

Another good reason for battery switches.....