Here''s the deal, I was going to hook up the toad and take it on an inaugural test run. 2008 Winnebago Destination 39 feet with two slidesFreightliner chassisCummins Diesel pusherGot it out of covered winter storage a week ago. They report having a difficult time getting it started after six months. But it was running fine for the trip home, even through a brief snow squall. Got home, full check out, all systems good.Take it for a check ride last week. No issues. Today, won't start. No chassis voltage anywhere. Coach power is fine. So I try the battery boost, after all, that is what it's there for. Hindsight says not the best idea, probably ever. Still not starting and suddenly wisps of smoke appears under the dashboard - left side. Immediate power down. Notify wife & son, position fire extinguishers at the ready. Start stage one troubleshooting- visual inspection. Wife is on iPad and googling symptoms, it seems that the battery boost feature can be irksome, and may smoke under load. Voltage checks show that the coach batteries are at 12.9 VDC. Chassis batteries are effectively dead at 1.70 VDC and show no charging voltage. This with shore power applied. What would you do next?Me, research in progress, theory of operation.

New chassis batteries..they're toast...now you could try and run generator and try to get a charge on them...but they are so dead that they are toast..note that if you use battery boost, start generator, then hold button boost down for a good 5 minutes to try and get something in there and try again..but with batteries that low, they are shorted out.

I guess the first question is was the batteries removed when in storage and did you guys recently re-install the batteries?The RV BATTERIES are SO EASY to get installed wrong mostly because of the BATTERY cable wire colors being different from Automotive wire colors...Something going to ground somewhere causing your smoking cables... If the START BATTERY has shorted core cells it should have tripped some fuse or 12VDC breaker somewhere before smoking wires????These are obvious comments here - MOTOHOMES and larger RV's have different symptoms than regular stand along trailers have.Roy Ken

First, I would try and remember what I left on that ran the engine batteries down once you got it home after the check ride. I would disconnect them if I cannot find the culprit and put a 10 amp charger on them for a couple days. They may not be toast, just lightly browned. Many MHs do not charge the engine batteries when on shore power... just the house batteries.

Something caused the chassis batteries to fry, you to need to check the coach charger output, as it also keeps a charge on the chassis batteries. Plug into shore power and measure the voltage out of the coach battery charger.

If you have another battery that you can use , Don't use a real good one. You can jump + to + and - to - and let set for a few hours, then put a charger on 2 amps charge for a few more hours, then take off the good battery and leave charger on the low battery, Let charge 12+ hours and then let rest for two and then check voltage. If it holding, then put back charger till fully charge up. 2 to 10 amps max till fully charged. new battery chargers will not charge a fully discharge battery, so that is why you need the good 12v battery to fib to the charger.

Chassis Batteries not charging. PERIOD | Good Sam Community

1BryNelson
Explorer
May 11, 2015
Clear sky's and no traffic wishes to you.
Big_Blue
Explorer
May 11, 2015
Well, the batteries have been replaced and the rig dropped off for annual servicing with a punch list of requested action items. I assumed that the chassis batteries were being charged from shore power. Intend to confirm reality with Winnebago this week.

The battery change was a typical adventure. Got the batteries and hardware at my typical source. Then figured out some of the hardware was not compatible, so ended dashing to a local commercial marine resource.

In hindsight, there were minor inconclusive symptoms last year. Low voltage alarm on start up & then cleared moments later.

Here's to an incident free season. First trip is two weeks from this Friday. Still need to do the load up.

Cheers,
pianotuna
Nomad III
May 10, 2015
Hi

Since you have solar, instead of a trickle charger look at either the Trik-l-Start or Amp-l-Start units.
FIRE_UP
Explorer
May 09, 2015
Big_Blue wrote:
All great advice.

Lessons learned:
Affirmatively charge the chassis batteries.
Battery boost is not a replacement for charged chassis batteries.
Shower power does not charge chassis batteries.
The roof solar battery charger is for the coach, not chassis.
RTFM.

The batteries have been pulled and are accepting charges from a ProLogic battery charger/conditioner.
All connections are being thoroughly cleaned because the manual says so.
A trickle charger is being researched and will be installed.

Big_Blue,
Well Sir, it sounds like so far, you may have slipped by in this incident with maybe just some scourned batteries. Since you've not stated that you've found anything else as the result of smoke from the dash area. And, I'm pretty sure you meant SHORE power instead of "Shower" power, unless you think your batteries need a shower.
There are so many folks that think the house battery charging system, be it a converter/charger or, in the case of most diesel pushers, an "Inverter/charger" also charges the chassis batteries.

Well, I'm not sure about many other brands/makes but, Winnes and Itascas had no such chassis battery charging system in place, from the factory, all the way up to around, early '06 or so. Many owners of those era coaches, remedied the situation with what's called the "Trik-L-Start". It's not a charger. It's simply an electrical mechanism that SIPHONS off, some of the intended charging for the house batteries, and sends it to the chassis batteries. And, the max it will give those is either .5 amps or, 5 amps, I can't remember.

I chose the route you're thinking of. I installed a three-stage NAPA battery charger permanently. I tied it into an un-used breaker in my 120VAC breaker panel. I then ran the leads through the side bulk head to the chassis batteries. And, that charger is controlled by a re-settable circuit breaker, just like the rest of the 120VAC components.

And, if anything should ever go wrong with the house battery charging system, (which can) the chassis batteries will still keep on charging, even when the charger is supplying the third stage, i.e. trickle.

Scott
time2roll
Nomad
May 09, 2015
Big_Blue wrote:
Shower power does not charge chassis batteries.
The roof solar battery charger is for the coach, not chassis.
RTFM.

A trickle charger is being researched and will be installed.

I recommend Trik-L-Start specifically designed for this purpose.
bullydogs1
Explorer
May 09, 2015
Once you get good batteries in there...you want a voltmeter...it should start and then put the voltmeter on the batteries to ensure your alternator is charging your batteries from the coach..If that's good a trick l start is in your future..If it shows the alternator is not charging your coach batteries, (no increase to 13.6 or so) then your alternator is bad as well....Start with the batteries..then check alternator.
dan-nickie
Explorer
May 09, 2015
1BryNelson wrote:
Are you sure that your coach battery charger doesn't provide charge to the chassis batteries?
I believe it should.

Mine does, but only after the house/coach batteries are fully charged first.
1BryNelson
Explorer
May 09, 2015
Are you sure that your coach battery charger doesn't provide charge to the chassis batteries?
I believe it should.
Big_Blue
Explorer
May 09, 2015
All great advice.

Lessons learned:
Affirmatively charge the chassis batteries.
Battery boost is not a replacement for charged chassis batteries.
Shower power does not charge chassis batteries.
The roof solar battery charger is for the coach, not chassis.
RTFM.

The batteries have been pulled and are accepting charges from a ProLogic battery charger/conditioner.
All connections are being thoroughly cleaned because the manual says so.
A trickle charger is being researched and will be installed.
msturtz
Explorer
May 09, 2015
The battery boost switch is for boosting low chassis batteries only not for connecting the fully charged house batteries to completely dead chassis batteries. You probably damaged the wiring and potentially the relay as well. Most likely something was left on that was connected to the chassis battery bank. You should replace the batteries. Not all coach manufacturers connect the shore power to charge the chassis batteries.