Question Chassis Battery 11.7

Scubawise · 09-05-2021, 03:00 PM

We traveled down a very bad road and setup camp.
Coach battery & chassis battery fully on generator.
Used inverter as usual and when used a lot coach battery drops to 11.7 which is normal for us.
This time chassis battery dropped to 11.7.
Stated coach engine and coach battery went up to 13.0 and I shut off after 2 minutes.
Turned off inverter.
Now coach battery at 12.1 and never went below 12.8?

Does inverter or coach batteries use chassis batteries?

Any ideas?

Scubawise · 09-05-2021, 03:08 PM

Started generator and both coach and chassis went to 12.6

Generator charges both?

Scubawise · 09-05-2021, 03:53 PM

I found this on our group.
Some folks are saying generator charges both coach and chassis?

I wonder if running the inverter for tv for 3 hours brought down house batteries and then drained chassis.

Never saw inverter/house batteries ever use chassis?

Does the Generator charge House AND chassis Batteries? - iRV2 Forums

https://www.irv2.com/forums/f121/doe...es-432109.html

taylorbob1 · 09-05-2021, 03:54 PM

Yes
Chassis battery & house batteries are connected for charging
- engine alternator charges chassis battery + house batteries
- generator and solar charges house batteries + chassis battery

That said, your chassis battery should not “drain” when using house batteries. You have a Solenoid in engine compartment that will keep that from happening.

Now, if yours is not functioning correctly, a faulty solenoid may be the issue

DavidEM · 09-05-2021, 04:22 PM

Yes, your Precision Circuits BIM 160 isn't working correctly. When the coach batteries are down below about 13 volts the BIM should turn off the connection to the chassis batteries. Obviously it isn't doing that.

At least on my 2021 Axis and I suspect yours as well, there are several connections to the positive terminal on the coach battery: the converter, the generator starter, the BIM and maybe a solar panel. Find the BIM red wire and disconnect it (and wrap it with tape so it won't short somewhere) until you can get it fixed.

Otherwise you run the risk of taking down both your coach and your chassis battery and you won't be able to start the chassis engine.

David

LifeisGoodinVegas · 09-05-2021, 06:08 PM

Thanks all I will either keep watching the battery level and use generator until home.

Where can I order a Precision Circuits BIM 160
Or will any rv tech have access?

LifeisGoodinVegas · 09-05-2021, 06:10 PM

This is my wife's account

LifeisGoodinVegas · 09-05-2021, 06:13 PM

Hi where is this located on the 2020 Vegas 25.6. Maybe a wire is loose from the gravel road?

taylorbob1 · 09-05-2021, 06:39 PM

Quote:

Originally Posted by LifeisGoodinVegas

Hi where is this located on the 2020 Vegas 25.6. Maybe a wire is loose from the gravel road?

On V-10 in on driver’s side front
See photos below…

* That said, are you hearing the “Clunk” after you turn off ignition key (unusually abt a minute or two later)
That clunk is the solenoid

LifeisGoodinVegas · 09-05-2021, 06:59 PM

No clunk sound ..I will look in that area

Scubawise · 09-05-2021, 07:11 PM

Quote:

Originally Posted by taylorbob1

Yes
Chassis battery & house batteries are connected for charging
- engine alternator charges chassis battery + house batteries
- generator and solar charges house batteries + chassis battery

That said, your chassis battery should not “drain” when using house batteries. You have a Solenoid in engine compartment that will keep that from happening.

Now, if yours is not functioning correctly, a faulty solenoid may be the issue

Thx did not know

generator and solar charges house batteries + chassis battery

taylorbob1 · 09-05-2021, 07:11 PM

Maybe someone on Forum can help out.
If BIM is disconnected, can a test be run to see if solenoid is properly functioning?

DavidEM · 09-05-2021, 07:32 PM

Well, the only test I could suggest is one he has already done: Start the chassis engine and watch the coach battery voltage. If after a few minutes it doesn't come up and match the chassis engine's battery voltage then something is wrong.

But as noted above, it could be a bad connection. Check at the BIM, and at the battery terminal before replacing it.

David

Pillbox · 09-05-2021, 09:01 PM

Kinda the same, but my chassis batteries will not charge on genny or shore. Still looking for the BIM. The trombetta works for emergency start.
Got clues on where they hide my bim? I have crawled the length more than once looking, of course I’m blind as a bat when looking for specific things. Help
Terry

Scubawise · 09-07-2021, 02:04 PM

From Precision below. Many a wire on bim lose?

Hello George, the BIM should only connect if one battery bank is 13.3v or greater and the other bank is 12.6v or less. If neither battery bank is charging the BIM should not be connected. It’s possible both batteries can be low and the BIM is not connected.

Daniel Dinovo

Technical Support

Precision Circuits Inc

2538 Wisconsin Avenue

Downers Grove, IL 60515

630-515-9100 EXT-704

630-515-9101 Fax

(Hours) Mon-Thur 7AM-4PM.

Fri 7AM -12PM.

Scubawise · 09-07-2021, 07:44 PM

Quote:

Originally Posted by DavidEM

Well, the only test I could suggest is one he has already done: Start the chassis engine and watch the coach battery voltage. If after a few minutes it doesn't come up and match the chassis engine's battery voltage then something is wrong.

But as noted above, it could be a bad connection. Check at the BIM, and at the battery terminal before replacing it.

David

Will check bim and battery terminal
Found this on thor site for me

Scubawise · 09-08-2021, 03:48 PM

Now this is strange ..I got home..plugged into 30 amp and both coach & chassis read 14 4..I wonder if when inverter wired to battery and or when both house batteries changed if somehow coach battery is bring read twice by bmpro controller. I have an appt with my tech today

**16ACE27** · 09-08-2021, 04:29 PM

Quote:

Originally Posted by Scubawise

Now this is strange ..I got home..plugged into 30 amp and both coach & chassis read 14 4..I wonder if when inverter wired to battery and or when both house batteries changed if somehow coach battery is bring read twice by bmpro controller. I have an appt with my tech today

Or maybe the converter is charging both batteries like it is supposed to?

Maybe break out the multimeter and read the battery voltages directly if you have a question about the accuracy of the BMPRO?

Scubawise · 09-08-2021, 09:25 PM

Kurts repair checked the issue..as stated here BIM appears bad. Kurt tested no current to coach battery when engine running & chassis being used when inverter on. I called Thor parts and said I am out of warranty and parts said mention to service as goodwill. Thor service shipping free & kurt said he would install free of charge..

Thx all

28Z · 09-20-2021, 05:10 PM

Hello everyone,
I'm new to this. I have a brand new Thor Four Winds 28Z, and here is Texas is too hot in summer, so I stored it (always stored plugged in to shore). I went to inflate tires and the chassis battery was weak when I started.
Does the shore power charges the chassis battery?
If not, then is it safe to use a battery charger and maintainer?
and if so, what type of chassis battery does it have, wet cell, gel, AGM, Lithium?

I got a NOCO Genius 5 charger and I have to choose a battery type. I couldn't find anything on the maintenance manual.
Thanks for the help!!

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