Charging chassis battery

jrwalkerpa1 · 03-30-2015, 08:46 AM

Looking for some help solving a mystery (?)

On a 2015 3010DS, I had assumed that the chassis battery was completely isolated from the coach batteries/ and 12 volt system...the sole exception being when the boost switch is held.

Lately my chassis (not coach) battery has seemed week so I have been testing it with a volt meter under several conditions, at rest X hours after any load, when charging, etc., etc...

Over the weekend, I tested it 2 hours after shutting off the engine and it read 11.9 volts....weak....again this is the chassis battery

But, then after plugging in the RV overnight, it read 13.6 volts the next morning...which seems(?) to indicate that the RV charger/converter is charging the chassis battery as well as the coach battery.

Any thoughts? I am not sure how that is possible...or maybe my meter is bad or my assumptions were wrong or ??????

funfinder5 · 03-30-2015, 01:06 PM

Yes, what your testing has revealed is correct. The coach has a BIRD system that will connect the two batteries (house & engine starting) together if it detects 13.x + volts from the house battery ( charging state)

funfinder5 · 03-30-2015, 01:10 PM

Correction, the BIRD connects both together if 13.x + volts are read from either house or engine battery.

jrwalkerpa1 · 03-30-2015, 01:21 PM

Quote:

Originally Posted by funfinder5

Correction, the BIRD connects both together if 13.x + volts are read from either house or engine battery.

Ok, great! I knew that the alternator would charge the house batteries going down the road but had thought it was a one way deal.. Didn't know that it was a two-way connection. But, glad to know it!

Thanks...I learned something new!

wana65stang · 03-30-2015, 02:17 PM

Quote:

Originally Posted by jrwalkerpa1

Looking for some help solving a mystery (?)

On a 2015 3010DS, I had assumed that the chassis battery was completely isolated from the coach batteries/ and 12 volt system...the sole exception being when the boost switch is held.

Lately my chassis (not coach) battery has seemed week so I have been testing it with a volt meter under several conditions, at rest X hours after any load, when charging, etc., etc...

Over the weekend, I tested it 2 hours after shutting off the engine and it read 11.9 volts....weak....again this is the chassis battery

But, then after plugging in the RV overnight, it read 13.6 volts the next morning...which seems(?) to indicate that the RV charger/converter is charging the chassis battery as well as the coach battery.

Any thoughts? I am not sure how that is possible...or maybe my meter is bad or my assumptions were wrong or ??????

The question is though why is your chassis battery dropping to 11.9 volts? The coach should not draw on the chassis battery while not running the vehicle engine.

jrwalkerpa1 · 03-30-2015, 03:34 PM

Quote:

Originally Posted by wana65stang

The question is though why is your chassis battery dropping to 11.9 volts? The coach should not draw on the chassis battery while not running the vehicle engine.

Yes, a separate issue from my "mystery" above, the chassis battery is failing. The coach is not drawing on it, its just not holding a charge.

I had to use the boost twice now to get the engine started. I had it load tested and its showing a bad cell. I'll be replacing it shortly. Its less than a year old so Ford is replacing it under warranty.

JohnGalt1061 · 07-06-2015, 08:53 PM

I have the same question as the OP regarding my 2015 Georgetown 351DS. When I'm plugged into 110V at the storage place is my chassis battery being charged?

Still Kickin · 07-07-2015, 09:00 AM

Yep. Modern MH's, RV's have a "battery control center" which monitors the batts (chassis and coach) and supplies current to both as needed from that device. The 110v feeds the converter, which then connects to the BCC. Im not familiar with your rig, but if you look around it is labeled as such.

The question you need to ask is; Who is John Gault! Kidding of course.

n-e-d · 07-07-2015, 11:08 AM

Quote:

Originally Posted by Still Kickin

Yep. Modern MH's, RV's have a "battery control center" which monitors the batts (chassis and coach) and supplies current to both as needed from that device. The 110v feeds the converter, which then connects to the BCC. Im not familiar with your rig, but if you look around it is labeled as such.

The question you need to ask is; Who is John Gault! Kidding of course.

(sorry ahead off topic) Answer is Barack Obama

JohnGalt1061 · 07-07-2015, 11:40 AM

Quote:

Originally Posted by Still Kickin

Yep. Modern MH's, RV's have a "battery control center" which monitors the batts (chassis and coach) and supplies current to both as needed from that device. The 110v feeds the converter, which then connects to the BCC. Im not familiar with your rig, but if you look around it is labeled as such.

The question you need to ask is; Who is John Gault! Kidding of course.

Thank you very much and yes that is the question I love when people ask.

RamblerGuy · 07-07-2015, 08:13 PM

I used the battery interconnect feature to recharge our toad battery once. The toad's auxiliary braking system ran the battery down after towing it 2 1/2 days without starting it. We had electricity at the campsite, so I ran jumper cables from the chassis battery to the toad battery. As the convertor charged the chassis battery through the battery control center's relay, it also charged the toad's battery.

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