Generator Battery

lwestbro · 05-25-2012, 04:24 PM

I have a 2002 Winnebago Journey. If I store it for more than a couple of weeks without running it, the generator won't start because the battery is dead. I shut the switch on the dash off, but the battery drains down anyway. What would be the best way to identify which battery feeds the generator and isolate it so that it doesn't drain down. Thanks!

skigramp · 05-26-2012, 02:10 PM

None of our real experts have stepped up to help you ... so I will try ...

When the genset will not start can you still start the engine without depressing the MOM switch on the dash?

answer is yes then genset is cranked by the house batteries ...
answer is no then the genset is probably cranked by the chassis batteries too.

Do the steps work ... the power to the steps come from the chassis batteries ...

Remember that deep cycle batteries are 50% charged when they read 12.o volts

I hope this helps you figure out your answer ...

doit2010 · 05-27-2012, 11:16 PM

What is the MOM switch?
If 50% charge is 12.0 what is the full charge reading?

jimbo16720 · 05-27-2012, 11:47 PM

Quote:

Originally Posted by doit2010

What is the MOM switch?
If 50% charge is 12.0 what is the full charge reading?

Should be a switch to change from house to starting battery. It might say dual and house or something like that. On mine which is an 86, if I press the switch to the right and hold it while starting the genny it starts off the engines battery. And 12.6-12.7 is full charge..12 is half and 11.6 is dead.

Dogpatch · 05-27-2012, 11:53 PM

On mine the switch says "Boost" which combines both house and chassis batteries.

clyon51 · 05-28-2012, 08:59 AM

Quote:

Originally Posted by lwestbro

I have a 2002 Winnebago Journey. If I store it for more than a couple of weeks without running it, the generator won't start because the battery is dead. I shut the switch on the dash off, but the battery drains down anyway. What would be the best way to identify which battery feeds the generator and isolate it so that it doesn't drain down. Thanks!

You have a common problem. The chassis battery is used for the generator starter in most MHs. In addition, most chassis batts will go dead after a week or two due to powering the steps/light and other phantom draws. The older the MH the more prevalent this seems to become. One way to fix this is to put a manual battery disconnect switch on the chassis battery. You still want to fully charge it once per month.

You probably have a second problem, when plugged into shore power, your system doesn't maintain the chassis batt. Most Winnies do have this system, but some don't. To check, hook up to shore power. With a volt meter check the coach batts, they should read in excess of 13v. Now check the chassis batt, if it reads under 13v, your system doesn't maintain it. A simple easy and cheap way to fix this is with a Ultra Trik-L-Start.

On your dash should be a Aux/Batt/Boost switch. This is used to temporarily connect the coach and chassis batts together and give you a "boost" from the other battery(s).

Probably the easiest way for you to tell which battery is used for generating starting, is to first remove the negative cable on the chassis batt. If it starts, the coach batteries are used.

John Hilley · 05-28-2012, 11:42 AM

"You probably have a second problem, when plugged into shore power, your system doesn't maintain the chassis batt. Most Winnies do have this system, but some don't. To check, hook up to shore power. With a volt meter check the coach batts, they should read in excess of 13v. Now check the chassis batt, if it reads under 13v, your system doesn't maintain it. A simple easy and cheap way to fix this is with a Ultra Trik-L-Start."

Winnebago didn't start putting them in until later on, maybe 2005 - 2006

smlranger · 05-28-2012, 08:01 PM

I have the same coach. The genset is started by the house batteries, not the chassis batteries on my coach. It is true that due to parasitic loads, the chassis batteries may/will discharge over a period of several days if you don't keep some sort of maintenance charge on them. Not sure why your house batteries are discharging especially if you turn off the dash switch. If your's is the DL, it should have a roof mounted solar panel that will provide some maintenance charge to your house batteries.

Suggest you check your house batteries with good battery tested or load tester.

Hikerdogs · 05-30-2012, 08:50 AM

If you disconnect the batteries using the factory installed switch (ours is in the stairwell) the batteries should last for months before discharging to the piont they won't start the generator. We regularly store our motorhome for up to 3 months with the batteries disconnected. The first thing we do when we bring it out of storage is turn on the batteries and start the generator.

Your batteries may either be getting so old they won't hold a charge or are not getting fully charged before you put it in storage.

The batteries are supposed the be getting charged anytime the engine is running. An easy way to check is go to the Oneplace monitor when the engine is running. It should show both the chassis and house batteries being charged at around 13.4 volts.
If it appears the chassis batteries are being charged but the house batteries aren't you may have a bad charging solenoid. This solenoid is supposed to connect all the batteries to the engine generator for charging when the engine is running. It's a fairly common part to fail over time and inexpensive to replace. We replaced ours a couple years ago for around $20.00

Dave78Chief · 05-30-2012, 10:48 AM

Reffering to the wiring diagrams for your WKP36C coach (Table of Contents), the generator uses the coach battery. I believe the only connections that are not shut off by the disconnect solinoid are the solar panel and the 300 watt inverter for the entertainment system (drawings are not clear for the inverter though). So possibilites are:
1. Batteries are old and will no longer hold a full charge
2. The disconnect solinoid is not disengaging (not an uncommon problem) leaving the rig powered on. Internal contacts get pitted and stick together.
3. Solar system has a problem resulting in battery discharge. Small wire from input side of switch (battery cable from AUX Battery Solinoid) goes to 6 amp Solar CB.
4. 300 Watt Inverter is being left ON or has a problem.
5. Somone has added a circuit to the coach battery side of the disconnect switch and is being left ON drawing the battery down.

Dave