Community Forums

brenthg · 08-15-2016, 09:58 AM

I am new to the Fleetwood Discovery 39S batteries setup and here's what I have determined how the 2 separate battery banks get charged. I have verified the charging sequence by testing the voltage of each bank with different scenarios:

1. Engine running, no generator, no shore power - Chassis Batteries charging.

2. Generator running, engine off, no shore power - Coach Batteries charging.

3. Shore power plugged in, no generator, no engine - Coach Batteries charging.

4. Engine running, generator running and/or shore plugged in - Both battery banks charging.

My previous coach was a Winnebago, and as long as I had 110v power in the coach, generator or shore power, both Coach and Chassis battery banks were being charged.

My question is, for extended stays where I am plugged in to shore power, do I have to routinely run the engine to keep the chassis battery charged?

**CLIFFTALL** · 08-15-2016, 10:01 AM

I believe your Coach will charge both on Gen. or Shore Power. My Bounder did.
Give FW a call at 800-322-8216. They'll email you your schematics

Old Bounder · 08-15-2016, 01:58 PM

Both sets of batteries should charge under all four conditions you have listed.

Your coach has a box called a BCC (Battery Control Center) that has circuits and solenoids in it to make that happen. HERE is a document that should explain how that happens, and should assist in determining why yours does not.

Al Fresco · 08-15-2016, 08:20 PM

brenthg,

I recently purchased a 2016 Flair 26e which gives the same charging results you reported. With either the generator or shore power supplying power, the chassis battery reads only 12.6 volts. This is not what would be expected if the converter in the coach is connected to the chassis battery. The coach batteries, under these condition, normally read 13.2 volts.

Be that as it may, I have gone a week on shore power without any drop in chassis battery voltage. However, I was not using the chassis battery as a power source during that time - unless the power shade on the front window is powered by the chassis battery. The shade was raised and lowered each day.

Old Bounder · 08-15-2016, 09:14 PM

Quote:

Originally Posted by Al Fresco

brenthg,

I recently purchased a 2016 Flair 26e which gives the same charging results you reported. With either the generator or shore power supplying power, the chassis battery reads only 12.6 volts. This is not what would be expected if the converter in the coach is connected to the chassis battery. The coach batteries, under these condition, normally read 13.2 volts.

Be that as it may, I have gone a week on shore power without any drop in chassis battery voltage. However, I was not using the chassis battery as a power source during that time - unless the power shade on the front window is powered by the chassis battery. The shade was raised and lowered each day.

Your Flair is also designed to charge the chassis battery from the converter (via Shore or Gen power) if/when the converter output is above 13.2V. The same BCC is used in your coach.

brenthg · 08-16-2016, 11:42 AM

Quote:

Originally Posted by Old Bounder

Both sets of batteries should charge under all four conditions you have listed.

Your coach has a box called a BCC (Battery Control Center) that has circuits and solenoids in it to make that happen. HERE is a document that should explain how that happens, and should assist in determining why yours does not.

I contacted Fleetwood Customer Service via email and this was their response, including a document explaining battery care and how they are charged in Fleetwood coaches.

Fleetwood MH Service <fleetwoodmhservice@revrvgroup.com> Today at 7:09 AM
To
Brent Headberg
Message body
The invertor will charge the house batteries first, then the solenoid will close at about 13.1 volts allowing the main battery to be charged. When you are travelling down the road, this is reversed, the alternator working with the main battery, charging it first, then the aux or house batteries. This happens without the generator running. I have attached a small article one of our techs wrote a few years ago to assist new owners with the design of this system. Hope this will help.

Cara Lynch
Administrative Assistant
cid:image003.jpg@01D1269B.6FB0D020
REV Recreation Group
1010 Commerce Dr.
Decatur, IN 46733
1-800-322-8216

Al Fresco · 08-16-2016, 12:30 PM

brenthg,

Thanks for including the Fleetwood battery charging information and download in your post. They address questions I had about the operation of the system and explain the voltage readings I am getting with various power sources. Much obliged!

brenthg · 08-17-2016, 06:17 AM

Quote:

Originally Posted by Al Fresco

brenthg,

Thanks for including the Fleetwood battery charging information and download in your post. They address questions I had about the operation of the system and explain the voltage readings I am getting with various power sources. Much obliged!

Hello Al,

The response I got from Fleetwood makes sense. So yesterday, I stopped by to confirm this sequence and this is what I found on my coach.

With the Generator running and engine off I get 12.4v on the Chassis Battery and 13.4v on the Coach Battery.

Based on what Fleetwood says, when the Coach Batteries are being charged and the batteries are reaching full charge, the voltage will slowly drop to below 13.1v triggering the solenoid to switch over and start charging the Chassis Batteries.

Is that the logic?

twinboat · 08-17-2016, 06:28 AM

No, your logic is backwards.

Anything over 13.1 should trigger the charging of the chassis battery.

The float voltage of most 12 volt batteries, ( the voltage to maintain full charge ), is 13.4 or so.

montyhp · 08-17-2016, 06:35 AM

Brent and Debbie,
I have the same coach and have had the same problem. It is either a bad fuse in the BCC or a bad solenoid. If your BCC circuit board (in the black box near your inverter) is the same is mine, there is a 3a fuse right at the bottom right hand corner of the board (I think it is #21 if memory serves) that feeds the solenoid control circuit. (I would check that first). The easiest way to check the fuses is with a test probe. You can touch it to both sides of the fuse to make sure there is voltage to both sides.

The Solenoid is a large one mounted on the back wall of that compartment. When the circuit board senses that the batteries meet the appropriate conditions (which you already described, with engine running the chassis batteries get to a certain charge level or with the generator running/shore power the house batteries get to a certain level) the circuit board triggers the large solenoid to close, thus combining the battery banks so they will both charge.

If you measure the voltage of each of the large solenoid terminals (the ones on the top of the solenoid) independently, you will measure the voltage of each battery bank. If the voltages are the same, then the solenoid is closed and both banks are charging. If the voltages are different, then the solenoid not closed. Fleetwood will tell you that you should hear a clunk from that solenoid when you push the aux start switch (at your left elbow when you are in the driver's seat) and that is true, but what they probably don't tell you is a clunk from the solenoid doesn't mean it is making proper contact inside.

I have had to replace the 3a fuse several times in the past. I also replaced the large solenoid with a more robust version (12v, 200a continuous duty) recently. Since then, no charging problem.

Finally, I recommend you join Discovery Owner's Association if you haven't already. Their yahoo group is like having 20-30 experienced Discovery mechanics on call at all times.

montyhp · 08-17-2016, 06:41 AM

Also, If you are relying on the battery voltmeters above the passenger's seat, the readings may be slightly different. There is voltage drop in the lines so the voltages are slightly different from the voltages measured with a voltmeter at the batteries. You can compare the voltages directly from the battery with those above the passenger's seat and get an idea of the amount of drop so you know how to interpret those voltages.

brenthg · 08-17-2016, 07:39 AM

Thanks for the info Monty, I will check that fuse this afternoon.

brenthg · 08-19-2016, 02:47 PM

Fuse for the battery boost switch (3amp) was blown. Are there 2 solenoids to the battery system? I only saw 1.

Didn't get a chance to run the generator long enough for the Xantrex to top off the house batteries, so I don't know if it will switch over and start charging the chassis batteries or not.

Brent & Debbie
2005 Fleetwood Discovery 39S
Knot At Sea

Sent from my iPhone using iRV2 - RV Forum

Gary RVRoamer · 08-19-2016, 03:45 PM

There is one solenoid that serves to cross-connect the two battery systems. It is triggered by two different ways:

1. Manually via the the Aux/Boost Battery switch on the dash
2. By the Battery Control Center when its voltage criteria are met

There is another solenoid but not really part of the charging system. It is the house battery disconnect solenoid and it is operated by a manual switch, usually located by the entry door. It's purpose is to literally disconnect the batteries from the coach wiring. However, if the solenoid is in the disconnect position, the house batteries won't charge either.