Batteries Overcharging Badly

[mhughes01]

I'm working with a pretty knowledgeable local general coach specialist and heavy mechanic in Edmonton who does his best to help us with our LXI.

Our chassis batteries weren't charging. Replaced all three. Still no go. I also replaced four of the six big 4Ds that weren't passing a load tests. All this just before she went in for her annual. Changed alternator (as one leg was dead), plus regulator, and a solenoid. That brought the "annual" on her to $6,500 with some other general preventative maintenance work. ;(( the alternator related bits were north of $3,000.

Picked her up thinking/hoping that was it. BUT, now all the batteries boil over so she's back at the shop. He's thinking bad batteries. Gauges and meters show over 14v, but water is boiling out and the H2S smell would knock a guy over. Says its overcharging from wall plug as well, but it wasn't doing that before I took it in (I have 50A for her in my shop and she is always plugged in.

It was running when I picked her up. Only thing I did was start Genny for some AC.

FIRST THING I NOTICED was signal light turned on wiper. Other mysterious lights on dash I've never seen before making me worry about massive overload.

Haven't heard from him for a few days and worried sick whatever they did burned things up. Anyone had anything like this?
__________________

Mike and Tracy - near Edmonton, Alberta, Canada
1999 43 LXI, "Maddy" - 60 Series Detroit
2006 Jeep Liberty CRD (Diesel) or Jeep Rubicon 4 Down Toad

http://www.challengerwest.com

[davidbrady]

Mike,

These problems are notoriously difficult to debug remotely and even harder when the coach isn't in your possession; nonetheless, I have a few questions:

1) What kind of house and chassis batteries did you install?

2) Which ones are off-gassing H2S?

3) What's your Xantrex RC7 charging configuration?

4) I assume you know about the 'aux-batt' switch on the dash and it's operation?

5) Have you checked the status and diagnostic LED's on the Xantrex chargers.

6) Are your Xantrex Battery Temperature Sensors adhered to the side of you house batteries?

I'm siding with your mechanic and his inclination that the batteries are the problem since you see this issue with both alternator charging and Xantrex charging. As a precaution, and given how much you've already spent, I'd replace the other 2 chassis 4D batteries. If 4 were weak the other 2 can't be far behind.

I'm suspecting a faulty cell or shorted cell such that the remaining cells are seeing excessive voltage. A simple test is to disconnect all batteries, let them sit for four hours and then measure their open circuit voltage; they should read 13.0V.

Lifeline provides these guidelines for load testing their AGM batteries:
1. Stabilize the battery at 68-86 deg F for at least 24 hours.
2. Bring the battery to full charge.
3. Discharge the battery at a constant current of 25 amperes until the voltage falls to 10.5 volts. Record the time in minutes.
4. Compare the measured discharge time to the published 25A rating.
5. If the battery delivers less than 80% of the rated capacity the conditioning procedure should be attempted an the battery should be retested.
6. If the battery delivers less than 50% of its rated capacity it should be replaced.

[mhughes01]

Thanks for the ideas David. I haven't heard back from the shop yet but will go in on Monday and see how they are making out. He was doing things with meters last week and is generally a pretty knowledgeable guy working on lots of Monacos, Newell's, etc. there are also not many options around these parts.

I've never touched any of the inverter charge settings, I don't even know how. But will figure out how to check if they are on Gel or FLA.

He said one leg of the alternator was dead, so that and the regulator got replaced. but who knows. That was nearly $3,000 right there with parts and labour.

I don't normally leave the aux batt switch on unless I need the extra boost.

Thankfully I had bills for the chassis batteries and 2 of the 4Ds. I am awful with receipts. He says they get about 1 new battery in 10 with dead cells right out of the box (Interstates). The chassis were Interstate 30s or 31s if I recall. I ended up welding hoops onto the battery trays (before all the h2s obviously with the old batts so I could pull the trays out with my quad as they were seized). The temp sensors have always been on the top of the batteries- do they need to be on the side? Not sure what to hold them with.

When I picked it up last week, It was showing over 14v on both dash gauges (house and chassis) and I didn't smell anything when hooking up my toad. It was a couple miles down the road when i stopped to double check the toad that i noticed the smell. All of the 4Ds seemed to be gassing. I couldn't tell on the chassis. The coach has always had FLAs since we've owned it and I've never touched the inverters.

Once it was back in the shop, and on his Snap On analyzer in the back on the batteries there was also over 14v and there seemed to be a lot of draw (I think he said 40 something amps on chassis, and 78 on house). I killed all the breakers for him and it was down to very little making me wonder if the only thing left drawing current was a shorted cell or two in the batteries. He told me his next step was pulling all the batteries and doing detailed testing, but I haven't gotten a call back as yet. He's got other customers to.

I was more frustrated than anything as we have a big trip planned to Illinois in a few days and they've had my coach for well over a month.

[cmillsap]

Mike,

David knows much more than I do. I think a process of elimination may help us diagnose here. If you could answer these questions, it may help to determine the problem.

1) The initial problem was the chassis batteries were not being charged.
a) Was the coach plugged in and sitting without the Aux Bat switch on?
b) Did the coach batteries charge up after running the engine?
c) Did you notice what the inverters/chargers were reading while the bus was plugged in to shore power before you took the bus to be repaired?

2) The repairs included new chassis batteries, new alternator, new voltage regulator, and a solenoid (?). During the process, 4 of the 6 house batteries were changed after testing them for load strength.
a) After installing the new batteries; did they check to see if the inverter/chargers would charge the batteries properly when plugged into 120V shore power or did they run the generator to supply 120v power to the inverter/chargers?

b) If they did either, were the batteries being charged properly by the inverter/chargers? Were they not boiling over? Was 13V showing on the volt meters on the dash and were the inverter/charger remote readouts showing a particular stage of charging?

3) The house batteries started gassing as you drove from the repair facility. Also, the DC voltage gages started to show 14V.
The questions now are what started the new problem of battery boil?
a) Is the new alternator current set too high at the voltage regulator causing the batteries to boil?
b) Is there a bad (shorted) cell in one of the new batteries?

Since the engine alternator and the voltage regulator were replaced and your batteries are boiling over when being charged by the new engine alternator and voltage regulator, I would suspect (as a possible cause) that the new voltage regulator is supplying too high voltage. It could be bad or adjusted improperly. If they had checked that the batteries were charging properly through the inverter/chargers, then we could have eliminated the bad batteries as the cause. But if they didn’t do that, we can not eliminate a bad cell in one of the new batteries.

Also, replacing less than all of the batteries in a tied group is not a good practice, especially if the group is aged to the point that some of them must be replaced. Once you solve the problem, I would also suggest that the 6 house batteries should be the same age and all alike.
Chuck

[mhughes01]

I had replaced the batteries myself in advance of taking it in because it was a two month wait to take it in. We get a short summer here.

There is one other shop here that was already fully booked into September by early May. At the shop I'm at where I normally go, I booked in May for July. Most of the big coach dealers around here have closed, not sure why as we have the most booming economy in the world here in Alberta, but they have.

The reason this all started was because the engine batteries would not charge while driving - they would charge up when plugged in - and I was fed up with having no headlights at the tail end of my 9 hour drive from a lot we own in a resort in southern BC.

Those symptoms already had me thinking alternator or regulator, or both.

I really don't know re #2 what kind of testing they did. Bas to inverters, the manuals are in the coach. I didn't know they had all the settings adjustable until I saw another post from David on this form. I have to look into that.

The alternator that was installed apparently can be "dialed down", but The mechanic said it wasn't enough and said he was also going to replace the new regulator as it might not be working properly.

[davidbrady]

Chuck, great questions and I completely agree about replacing all the batteries in a bank when renewing batteries. Many years ago when I bought my coach from Parliament Coach they told me when they prepare a coach for sale it automatically gets all new batteries. They're convinced that the money spent upfront is ultimately less than the money spent on techs chasing a variety of ailments most of which turned out to be related to faulty batteries.

Mike,

Here's a wild guess. Since the tech isn't a Wanderlodge expert it's possible that he may not have wired things up properly. You said he replaced a solenoid. I suspect the solenoid he replaced is the 'aux batt' solenoid. There are two diodes on that solenoid (actually three but one is for flyback current) that allow the dash switch or the engine start circuitry to enable the 'aux batt' solenoid.

If he failed to wire in the diodes or if they're reverse biased then the solenoid won't be turned on as it should. When the engine is started the chassis batteries act thru one of the diodes to turn on the solenoid thereby connecting the house battery to the chassis battery banks.

Here's what I'm thinking. The 50DN alternator sense wire may be wired to the chassis batteries, but the alternator charges the chassis batteries thru the 'aux batt' solenoid. If the solenoid isn't automatically activated while you're driving (aux batt LED on the dash is off), then the 50DN is always reading a low voltage. Since it's reading low, the 50DN voltage regulator cranks up the field current which results in the 50DN putting out excessive voltage. Guess where all this voltage is going? That's right, to the house battery bank. In short, your 50DN may be boiling your house bank because it's using the chassis bank to sense voltage but the chassis and house banks aren't connected due to incorrect or missing circuitry at the 'aux batt' solenoid; hence, all the 50DN power is going to the house bank with no voltage regulator feedback.

[mhughes01]

Thanks guys.

David, this sounds very plausible. I will print the technical part of these posts off and share them with him on Monday.

Thanks so much,
Mike

[davidbrady]

Mike,

Here's what the diode configuration around the 'Aux Batt' solenoid should look like. I penciled in the diode part numbers in red:



You should be running a Delco Remy voltage regulator part number: 19020413. I see now that this part number has been superseded by: 10503807

Here's a Delco Remy document, from our Document Library, on retrofitting the 10503807 Voltage Regulator: Delco Remy 50DN Voltage Regulator.

Here's a document from our Document Library that shows how to test the Alternator: Series-60 50DN alternator test.

Here's a document from Blue Bird (also in our Document Library) that suggests a modification to the voltage regulator wiring: Voltage Regulator Wiring Modification. The new voltage regulator, 10503807, is five wire: Field, Ground, Battery, Ignition, and Sense. The relay in this document is no longer necessary since there is a relay built-in to the voltage regulator for the VR's Ignition terminal. Notice how this document suggests moving the Sense/Battery wire from the chassis battery bank to the coach (house) battery bank. George Morris (Ex Blue Bird employee and Wanderlodge expert extraordinaire) suggests that the Battery and Sense leads be connected to the first insulated stud on the aluminum heat shield where the alternator output connects directly. It's best that this connection be made thru a fuse or a 15A circuit breaker.

For better or for worse the 'Aux Batt' solenoid is the original Wanderlodge configuration interfacing the chassis and house battery banks. Someday it'd be fun to review this setup and to possibly isolate the banks better with Battery Isolators, or similar technology. A Battery Isolator will allow the Xantrex chargers or the 50DN alternator to charge both banks but it won't allow one depleted bank to discharge the other bank. There's definitely room for improvement over the original design using standard and available technology.

[davidbrady]

Thanks a bunch Rich for taking the time to search for and post the LXi battery charge circuit document. I converted it to a pdf and uploaded it to our Document Library under Models->LXi->LXi Battery Charge Circuit.pdf

If you have any more I'm more than willing to add them to our Library.

[pgchin]

Two votes for the new regulator not being rewired properly to retrofit the bird's electrical system, I believe David may have nailed your initial issue. This has been seen before. Also, if you and he (your mechanic) have time I'd disconnect each battery both the chassis(group 31"s) and the house (4D's) and load test each one as well as meter each one for voltage. Each cell of a battery you loose will drop you 2 volts per cell/batt......... overcharging batteries, even new, will cause them to prematurely fail and short inducing new issues you did not have before and cause both you and he to "chase your tail", install more parts, etc......................good luck and sorry you missed you special trip.......it is a bummer!
FWIW, just one shorted cell in just one battery of the entire string will cause both the 50DN or the inverters to try and satisfy the load, keep charging all batteries and they will ALL overcharge, get hot, start warping plates, etc.
My apologies for the late response, I've been traveling for 5 days and was not on the internet.............