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straycatboat · 03-13-2025, 12:29 PM

I have a 2024 Beyond and I have it in storage for the last 3 months plugged in.
I keep getting notices from Ford Pass that my chassis battery is low.
Does the coach charger also charge the chassis battery if so how can I diagnose the issue?

Jim_HiTek · 03-13-2025, 12:50 PM

Get a Digital Voltage meter and measure the voltage across the house batteries, than across the chassis batteries. They should both be 13.xx volts range. Mine today are 13.4V & 13.2V. If your chassis batts are down well below that, then you likely do not have an aux charging system for the chassis batts.

But, some RVs do come with a bi-directional charging system built in and if your's does than something is wrong with it. Should be in your documentation. Some manufacturers make it optional.

straycatboat · 03-13-2025, 02:50 PM

Quote:

Originally Posted by Jim_HiTek

Get a Digital Voltage meter and measure the voltage across the house batteries, than across the chassis batteries. They should both be 13.xx volts range. Mine today are 13.4V & 13.2V. If your chassis batts are down well below that, then you likely do not have an aux charging system for the chassis batts.

But, some RVs do come with a bi-directional charging system built in and if your's does than something is wrong with it. Should be in your documentation. Some manufacturers make it optional.

Coachmen said that the BIM is not working and it's under the seat?

Jim_HiTek · 03-13-2025, 07:38 PM

Not a problem, it's near spring so maybe a trip coming up?

And/or you could do a couple things...take it to a shop, or diagnose it yourself, or get a Trik-L-Start device (~$80) or even a 120 Vac 2.5 amp float charger (~$25) from WM in their automotive section. I wouldn't let it stop any upcoming trip out of the cold weather.

If it's been 3 months without discharging and now it is? Interesting...large charging solar panel has too much snow on it perhaps? But the BIM should be doing something. They are simple circuits so I'd look for a poor connection somewhere.

straycatboat · 03-14-2025, 06:06 AM

Quote:

Originally Posted by Jim_HiTek

Not a problem, it's near spring so maybe a trip coming up?

And/or you could do a couple things...take it to a shop, or diagnose it yourself, or get a Trik-L-Start device (~$80) or even a 120 Vac 2.5 amp float charger (~$25) from WM in their automotive section. I wouldn't let it stop any upcoming trip out of the cold weather.

If it's been 3 months without discharging and now it is? Interesting...large charging solar panel has too much snow on it perhaps? But the BIM should be doing something. They are simple circuits so I'd look for a poor connection somewhere.

I would like to find the BIM and diagnose it, but I don't know which seat to start looking under. They are all screwed down. Also I have been getting these notifications for 3 months but I thought it was for another Ford vehicle I owned, that I drive everyday

Jim_HiTek · 03-14-2025, 09:19 AM

Aw, that's a Class B. Last years model. Very modern. There should have been a owners guide that came with it. I've added it here.

I believe they are talking about the BMS module. And it seems you have Lithium batteries so the suggestions I made above won't apply to that type.

Isn't it still under warranty? Take it back to where you bought it maybe?

Did they mean the module is in the compartment under the seat? Outside access? I think you should call them back and ask for a technician that's familiar with the BMS.

straycatboat · 03-15-2025, 06:11 AM

No owners guide, and its a generator model. Too far to go to the dealer.

Jim_HiTek · 03-15-2025, 09:08 AM

Here is a direct link to the owner's guide...Coachmen RV Owner's Kit

d23haynes57 · 03-15-2025, 09:27 AM

Quote:

Originally Posted by Jim_HiTek

Aw, that's a Class B. Last years model. Very modern. There should have been a owners guide that came with it. I've added it here.

I believe they are talking about the BMS module. And it seems you have Lithium batteries so the suggestions I made above won't apply to that type.

Isn't it still under warranty? Take it back to where you bought it maybe?

Did they mean the module is in the compartment under the seat? Outside access? I think you should call them back and ask for a technician that's familiar with the BMS.

If it has Lithium House batteries it is extremely unlikely that the house battery system would also charger the chassis battery. Possible yes. That would need to be added.

Jim_HiTek · 03-15-2025, 10:10 AM

The manufacturer told OP that his BIM is not working. They should know what battery type and setup the OP has via the VIN#.

d23haynes57 · 03-15-2025, 10:19 AM

Quote:

Originally Posted by Jim_HiTek

The manufacturer told OP that his BIM is not working. They should know what battery type and setup the OP has via the VIN#.

Key word, should. Ideally there should be metering ad indicators to display battery charging status even for the chassis battery if it is being charged when connected to power.

chs · 04-02-2025, 04:57 AM

So any update on this problem??
I'm betting that the BIM was ok and (like most B's and C's) does not have the ability to charge the chassis battery from either plugged into AC or the inverter. Only to charge the house batteries from the alternator.

straycatboat · 04-03-2025, 06:07 AM

Quote:

Originally Posted by chs

So any update on this problem??
I'm betting that the BIM was ok and (like most B's and C's) does not have the ability to charge the chassis battery from either plugged into AC or the inverter. Only to charge the house batteries from the alternator.

I really did not diagnose the issue, Just put a trickle charger on the chassis battery while in storage.
I don't think the Coachman tech was correct in telling me that the BIM is faulty.
Betting your correct.