Chassis batteries

Laughrw · 11-11-2019, 12:47 PM

I have a 2015 itasca solei 34T. After period of time my chassis batteries need to be charged. I am plugged into shore power but my chassis batteries are not charging. Has anyone had this problem and how was this problem fixed? I had contacted Winnebago tech support and they said I have a battery isolation manager problem. Any thoughts?

grtharris · 11-13-2019, 02:54 PM

Laughrw, Yes your coach has a Battery Isolation Manager and should be charging the chassis along with the coach batteries. First check that the chassis battery disconnect is not on. There is a fuse next to the battery isolation relay that should be checked. Then with a voltmeter start checking voltage levels in the circuit from the batteries back to the Battery Isolation Manager.

**creativepart** · 11-13-2019, 04:06 PM

The BIM can stop working correctly and this can lead to your chassis battery not charging as it should. Generally, as soon as your house batteries are fully charged (I think it's at 12.6v or so) the BIM will automatically switch your charger over to start charging your chassis batteries. My memory is the BIM will work to bring your chassis battery to 12.3v. (Hope I'm remembering that correctly.)

Of course, check the water level in your chassis battery, check the cables for looseness or corrosion, too.

My Winnebago had a non-functioning BIM and I had it replaced and that fixed the problem.

Bwdonald · 02-06-2020, 07:28 AM

I am experiencing this issue as well. I have a 2019 Navion. Any idea where the BIM is located or the chassis battery disconnect? I keep my camper about an hour from the house so just want to have as much information as possible when I go to investigate. Thanks for the help.

Laughrw · 02-07-2020, 09:01 AM

Not sure where the chassis battery disconnect or the BIM is located on the Navion I have a 2015 Itasca Solei 34T and mine are located by the chassis batteries. I just keep a trickle charger on my chassis batteries to keep charged

Sandy D. · 02-08-2020, 09:48 AM

We had a problem with the chassis battery not holding a charge even though we were plugged into shore power. We used a battery maintainer until we could replace the BIM. On our 2014 Sightseer it is located near the right front tire, behind the chassis circuit breaker panel. Access is from the forward outside compartment. Seems to have solved the problem. The replacement module looks completely different than the old one and the fastening brackets are in a different position. We still need to take care of that issue. Glad we had an extended warranty. In the first 3 months of ownership, we had this, a problem with the stove-top and a faulty furnace thermostat. Happy Hal's repair service in Las Vegas helped us out and James, the owner was great.

NavionRob · 02-16-2020, 10:57 AM

I'm a 2020 Navion 24D owner and I'd also appreciate any help with locating the BIM. My new unit barely started after 3 weeks in storage and I presume that the chassis battery wasn't getting any boost from the shore power that was plugged in during that time. I purchased a Trik-L-Start thinking that was the solution I needed. But I haven't installed it because of my uncertainty with where the BIM or battery isolator is located. I found something called a SC-01 solenoid (see photo below) next to my house batteries in the footwell of the coach entrance steps. It was marked Chassis / Ground / House, which indicates this is where I should connect the Trik-L-Start? Anyway, if anybody has any helpful input I'd appreciate it.

grtharris · 02-16-2020, 01:26 PM

NavionRob The SC-01 was added as part of the Feature code 22N (lithium Ion Batteries) it is called a CONTROLLER-SOLENOID,ALTERNATOR, so I assume it as to do with charging the batteries when the engine is running.
NOW, you also have a Charge Mate Pro 40 under the passenger seat which kinda does the same thing. The Charge Mate looks like it should keep you chassis battery charged when connected to shore power and the batteries are not disconnected.
Here is the link to the Charge Mate Pro 40
https://www.mastervolt.com/products/...e-mate-pro-40/
Can you see a manufacturer on the SC-10 unit?

NavionRob · 02-16-2020, 03:26 PM

Thanks, Grant. The manufacturer's name was not visible on that solenoid. I'll look again when I get my Navion out of storage this Tuesday. I'll also look under the passenger seat for that Charge Mate Pro 40. That should be the place to connect my Trip-L-Start. I'll confirm later this week.

J99 · 04-10-2022, 12:12 PM

Quote:

Originally Posted by Bwdonald

I am experiencing this issue as well. I have a 2019 Navion. Any idea where the BIM is located or the chassis battery disconnect? I keep my camper about an hour from the house so just want to have as much information as possible when I go to investigate. Thanks for the help.

Hello BWDonald: I have the same MH; Same Chassis Battery Drain issue...
Did you resolve this issue? Do you get a description/picture of the BIM or Disconnect? Appreciated.

**creativepart** · 04-10-2022, 02:50 PM

Quote:

Originally Posted by J99

Hello BWDonald: I have the same MH; Same Chassis Battery Drain issue...
Did you resolve this issue? Do you get a description/picture of the BIM or Disconnect? Appreciated.

Welcome J99!
Just an FYI to let you know that BWDonald posted his comment over 2-years ago. And more importantly he has not revisited this website since a day or two after he posted his comment.

It's always better to start a brand new thread with your problem or question than to jump onto an older, long dead thread.

Hopefully someone else will see your comment and jump in to help.