Charger/inverter battery problems

[HD4Mark]

Our first real trip in the new to us MH (see signature) and everything almost went perfect. Got to the CG after the 1600 mile trip and parked in a temporary spot for two days since we got here early and our site was not vacant yet. All set to move and we notice the fridge is flashing "low DC". Checked the house and engine battery voltage at the power center and sure enough both are around 9V. Had to get a jump start to get her going.

We are guessing that the breaker was tripped for the inverter/charger or something. I can hear it humming now so I assume it is charging. The house batteries are up to 13V, engine 12. I pulled the leads off and checked the voltage on each battery not connected to the coach and they are all similar. Is there some way I can test to see if indeed the charger is charging? There is a solar charger on the roof also.

12 volts is a little low for the engine batteries also. If they don't get any higher should I be taking them to a parts store to test them. I guess I can try to start it up and if it doesn't go that will help with that decision.

The Dimensions inverter readout says inverter stand by override by charger. Charger float mode 13.1V 10Amps if that helps.

We don't really know how old the batteries are but appear to not be original and no dates on them, of course. I did check and tighten the connections. There are 3 house deep cycle and 2 engine batteries that are Motorcraft fleet. Why Ford batteries in the Freightliner I don't know.

[GaryKD]

Hi Mark,
3 coach batteries leads me to believe you have 12 VDC batteries for the coach. 12 VDC is low for any 12 VDC bank of batteries. Does your coach charge the engine and coach batteries when connected to shore power?

Before pulling the batteries, check the water (if flooded) . Let the batteries charge overnight. Once fully charged, disconnect the batteries from the coach. Do not disconnect them from each other, just from the coach. Let them sit for a couple of hours and take a VDC reading. The reading should be 13.6 VDC or higher. If low, it is time to take the batteries to the battery or auto parts store and have them checked out.


The 13.1 VDC float/standby charge is a bit low. It is usually around 13.5 VDC.

[tomsm]

Mark - in '04 Winne didn't provide a charge to the chassis batteries from the inverter/charger. The chassis batteries are only charged when the engine is running. They subsequently started installing a Trik-L-Start which does charge the chassis batteries when the house batteries are being charged.

Many of started using the Trik-L-Start long before Winne started installing it. I've been using one for about 5 years and it's been flawless. There are other products out there that do the same thing, but I only have experience with the Trik-L-Start.

Here's a link: Ultra TRIK-L-START Starting Battery Charger/Maintainer

[HD4Mark]

Thanks Gary & Tom,

All of them are "no maintenance" so adding water isn't an option. I never gave a thought to the charger not charging the engine batteries. Why do you suppose both banks discharged?

I thought about a Trick-L-Start and while freezing my rear end off checked to see if somehow I had one or what I needed to do and decided to wait until spring. If I just jumpered the battery banks together would the engine batteries charge?

[tomsm]

Mark - I think the charger was not charging either bank when you were in that temp site. Possibly the A/C shore power voltage was low and the charger shut off to protect itself.

As for jumpering the 2 banks together, technically it's wrong because you have 2 different types of batteries (Starting and deep discharge) that require different charging rates, etc. However...after you start the engine, a solenoid energizes and connects the 2 banks together so that the engine alternator can charge both banks. This is same solenoid that energizes when you push the "AUX START" switch on the dash. I have even seen a popcicle stick stuck under that switch on a dealer's lot to get some charge into the chassis/engine batteries.

Some people say that switch is only for "momentary" use, but all it does is close that solenoid. If you drive for 8 hours, that solenoid is closed for 8 hours so that is hardly "momentary" use.

Your charger goes through 3 stages - "bulk", "accept", and "float". If you decide to bridge the 2 banks with either jumpers or holding down the aux start switch, you should probably disconnect from shore power and then reconnect. That will start your charger over in bulk mode which will kick out a lot more amps than float.

Connecting the 2 banks is not a long term solution, but you might want do it for a few hours to get some charge into the engine batteries. Incidentally, you're right, Motorcraft is not EOM from Freightliner.

[HD4Mark]

Tom,

Good info thanks. About the Trick-L-Start. If you have one did you install it using the instructions WIT has to connect it to the solenoid? I took out the 47 screws that hold the cover over it off to take a look at how it is connected and decided connecting it to the batteries like in their web site would be good enough.

For now I may just get a trickle charger and plug it in to charge up the engine batteries and wait until we are home for the Trick-L-Start.

BTW I had to laugh when I looked at their web site for the first time. The Vectra in the photo could be ours. Even the same colors.

[Duner]

Mark,
There's a very good chance that the solenoid that shorts the two battery banks together is not functioning very well and yours may be shot. Those solenoids are marginal for the amps and duty cycle in the motorhome application. The contacts build up some resistance from all the arcing and won't short together.

If yours is marginal, you may be able click the switch several times to get it to short the batteries together. Put a matchbook or something under the momentary switch to hold it down while camping, then measure the volts with a digital meter right at the solenoid and see if the voltages on both battery banks are the same.......if it is the same the solenoid is working. If it's intermittently working, then it's going to continue to be a problem til its replaced or repaired.

You can replace the solenoid for $20 to $35 or do like I did and take it apart and clean up the contact surface. It doesn't take too much time to use a small screw driver to pry open the crimp on the aluminum cover. Once open, all the parts are exposed and with a little sandpaper, you can smooth out all the copper surfaces. I cleaned mine two yrs ago and it's been working just like new.

Good Luck,
Bill

[tomsm]

Yes, I do have mine connected at the solenoid, but I deviated slightly from the way Winnie connects them. The way they do it, if you switch off (disconnect) your house batteries while in storage, the Trik-L-Start gets no power. Originally, I had to store outdoors with no shore power and I wanted the power from the solar charger to be shared with the chassis batteries. So, I connected the house battery lead to the hot side of the disconnect solenoid. Doing it that way, you can hit the house battery disconnect to stop the parasitic drain and still get solar power to both banks. I took the easy way and used the alligator clips, intending to go back later and hard wire it. Well, 6 years later and the alligators are still in there and working fine.

Surprisingly, that little 10w solar panel kept all 5 batteries charged. I've read several times on this forum that the 10w panel is useless. Maybe I got lucky and they accidentally installed a 25w panel on my roof... Whatever, it kept all my batteries in tip top shape for 2 years until I got into covered and powered storage.

My access may be different from yours, but I only have to turn 4 twist-locks to get the front panel off the box that houses my 2 solenoids and all the breakers and relays. My solenoid/breaker box is mounted on the firewall just above the Onan. There is an opening from the back side of that box to the area beneath the dash. That was the main reason I chose to mount it there - so I could have the Trick-L-Start module inside to monitor the LEDs.

[tomsm]

Mark - I would suggest going ahead and getting the Trick-L-Start if you're going to be there long enough to get it delivered. Just hooking it up at the batteries is even simpler than a trickle charger since it needs no external power. Just hook it up with the alligator clips and move it to the solenoid area later, if you want...

[Gary CA]

Mark: Quick note, my 12 volt house batteries just died in my 2004. Yours are probably shot also, the 9v symptoms were the same as yours. I'm in the process of installing 4 six volt. Good luck.

[HD4Mark]

Gary,
Thanks for the response. I don't think any of the batteries are originals. The house batteries have come back nicely. I just checked and they are at 13.3V and have held that for days. The engine batteries I am not so sure. I put a small charger on them and they are holding at 12.1. Going to try starting it up sometime later today and see if it fires up. Then decide what is next.

A Trick-L-Start is planned for after we get home. I think we will be at the CG long enough to get one delivered here but there is no sense risking it.

[wa8yxm]

Is there some way you can tell if they are charging... YES, there is. And it's easier than you can imagine.

http://www.sears.com/shc/s/p_10153_12605_03482369000P

It's that easy.. Three steps.. Purchase such a meter (NOTE that is an example) make sure the meter can clamp on a DC lead please

Then without shore power connected clamp on to the NEGATIVE battery lead (Assuming there is just one of those) and turn on some lights, read the meter (Should be one to two amps for each bulb lit) The meter may show something like -6 or it may just show 6.. (I'm assuming 3 1156 type bulbs here and again rounding) NOTE the presence or absence of the minus sign this is important

Now plug in.. You should see both the sign and number change.. If you saw, say -6 in the first mesaurement and you now see 10 (no minus sign) you are charging

It's that simple.

[Wayne M]

Mark,
I don't know what year Winnebago started using the Trick-l-chargers to charge both the house batteries and the chassis batteries. I would put mine in storage and turn off the disconnect for both to come back and find low voltage batteries. A call to Winnebago confirmed that my 2008 did charge both sets of batteries, but the disconnect switch for both had to be "ON." I have not had a problem since in maintaining voltage.

A suggestion: Call Winnebago and speak to a technician. If you give them your serial number they will pull up your build (I hope the have one for that year) and they will be able to tell you how your specific coach works.

Good luck.

[Beabop]

We have our Trickle Charger connected to the chassis batteries. It is sitting on the shelf beside the bed where we can see it.