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Sippy99 · 04-07-2020, 01:28 AM

I keep hearing conflicting information as to of the BCC charges the house batteries. I charged the house batteries to 13.3 volts and ran the engine with the house lights on. The batteries just showed a slow drain. If the BCC was connecting the house batteries with the alternator, shouldn't I see the house batteries voltage match the chassis battery (about 14.4v) when the engine was running? Do I need to buy and hook up a BIRD system? Should I hook one up? Does anyone know for sure how to tell if the BCC is supposed to charge the house batteries? The owner's manual says it does, but I don't see any proof of this in my coach.

vsheetz · 04-07-2020, 01:56 AM

When no charging is active the house battery terminal and the chassis battery terminals will read a bit different voltage (12.something), measured to ground.

When charging voltage exists (13.something), the charge relay in the BBC closes connecting the battery banks together. Both battery bank terminals should read the same voltage.

If the is a AUX or Boost switch, typically it uses the BBC - closes the relay connecting the battery banks together.

twinboat · 04-07-2020, 04:43 AM

Yes the house batteries should charge while the engine is running. A isolation system combines the start batteries to the house batteries for that.

Push and hold the boost or aux start switch, while the engine running, and see if the house battery voltage starts to climb.

If it don't, most likely the solenoid that connects the batteries together is bad. Common problem.

Pushing the boost switch on and off should make the solenoid clunk. That's how to find it.

Disconnect both batteries and pull shore power before working on it.

Sippy99 · 04-07-2020, 08:22 PM

Oh wow! I turned the vehicle on and trapped the BCC with a hammer, as if it were a small starter. There was no clunk that occurred (the clunk was always heard with the key rotated to the "on" position) but the house batteries started charging at 13.3 , the left side of both main connections to the BCC jumped to13.4, and both right side BCC terminals jumped to 13.7. Lastly, the vehicle battery was charging at 13.8.

Before I claim victory as a potential diagnosis of a tired BCC needing replaced, I need to be sure that I run a few more tests to ensure this wasn't a function of vehicle run time or pressing the aux start.

I've tried the aux start and time method in the past, so I feel those are ruled out as fixes, but I feel as though if the tap method works, then I will need a new BCC cylinder thing (insert technical name here).

(Finger pointing you technical thing)Attachment 280861

Sippy99 · 04-07-2020, 08:27 PM

You guys are amazing! Thank you so much for your support. I could not have done this without the help of such a giving community! I will keep you updated with future findings as I continue my testing.

Sippy99 · 04-07-2020, 09:00 PM

It would appear as though the BCC charges house batteries every time now. My conclusion is this: since I had to jar the bottom solenoid into function, this means that BCC is growing tired and will soon need replaced. Can anyone refute this conclusion or add further insight?

HarryStone · 04-26-2020, 10:49 PM

You can just replace the defective solenoid. Tekonsha 7001 Battery Switch-4 Terminal, 12 Volt Continuous Duty, Insulated, if it's the same as my Daybreak

hawkeye1995 · 04-27-2020, 12:36 AM

Yes, as HarryStone said. I have a Damon Daybreak and I had to replace the solenoid. The BCC circuit board will determine which battery to send current to, depending on the battery voltage, but this solenoid is the actuating device to make this happen. It is suppose to be constant power. So they will burn out.

twinboat · 04-27-2020, 05:57 AM

Quote:

Originally Posted by hawkeye1995

Yes, as HarryStone said. I have a Damon Daybreak and I had to replace the solenoid. The BCC circuit board will determine which battery to send current to, depending on the battery voltage, but this solenoid is the actuating device to make this happen. It is suppose to be constant power. So they will burn out.

Actually, the BCC will sense the charging battery and parallel it to the battery not being charged.

The chassis and house charging systems are always charging their respective batteries. The BCC interconnects them.