Community Forums

wqmiller · 04-07-2021, 09:31 PM

Trying to help a friend who owns a 2017 Anthem.....the coach is plugged into 50 amp shore power continuously but he discovered the chassis batteries completely dead and after two days of charging with external charger batteries would not take charge. Completely dead. He purchased and installed new batteries. The Vega panel shows the voltage level of the new batteries to be 12.7. That is with the coach plugged into shore power, the voltage remains at 12.7. Question: should the chassis batteries be receiving charge from the inverter charger? The house batteries show charge function is working (13.5 to 14.1). Also when engine is running alternator is applying 13.9v to the chassis batteries. Thanks for any help. Don’t have any electrical schematics so hard to troubleshoot.

Gary.Jones · 04-08-2021, 07:25 AM

The chassis batteries should be receiving a charge if their resting voltages is (I think) below 12.6 volts. If they are above 12.6 volts, then the charging system will not put charge to them until they fall below 12.6. Our Voltage and charge expert is 757Driver and Don will be on here in a few hours and verify the information that I am telling you. I may be a little off absolute but I am pretty close.

The same is true when your friend is running down the road. There is a component called the BIM relay which will mainly charge the house as you travel; but then every so often, it will check the chassis batteries and see if they are up to charge and if not, throw the charger from the alternator to the chassis battery pair (engine start batteries) but only for a specified amount of time (I think it is an hour) before going back to charging the house battery bank.

If you buddy is at 12.6, that is the charge that is about right for a fully charged bank of chassis batteries and there should be no active charge going to them. If there was, they would be getting a voltage around 13.4 volts.

Gary

cavie · 04-08-2021, 07:35 AM

Since you used the term Batteries, I'm gonna assume you are confusing Chassis with House batteries since I have not heard of more than one chassis battery. But then I don't sleep at Holiday Inns.:roller

If that is the case I'm also gonna assume that the Battery Disconnect ( Salesman Switch) is off. Did he have the batteries tested before replacing them?

Gary.Jones · 04-08-2021, 07:38 AM

If his friend has a Entegra, then he has two 12-volt chassis batteries and either 4 or 8 6-volt house batteries.

Gary

Ray Huffman · 04-08-2021, 09:51 AM

When one of my coach chassis battery shorted it tripped the battery merge breaker. It is located 4th compartment on the passenger side behind a panel. The battery merge connects chassis and house batteries as needed when the chassis batteries fall below 12.6 volts.

wqmiller · 04-08-2021, 09:57 AM

Gary,
Good info! I didn’t know if the Integra line had a separate function to monitor/control chassis battery charge function. I own an Newmar product and understand this function pretty well. So your input is very helpful. I left it unplugged overnight just to get the chassis batteries to draw down below ~12.6v. I will get back to the unit late today and continue the research. BTW where is the BIM located?

I discovered the master power switch just inside the door switch is inoperative. Doesn’t function at. Different problem altogether, I think.

Good info...thanks again!

Quinton

Gary.Jones · 04-08-2021, 10:19 AM

When Don (757Driver) wakes up and starts looking at iRV2 (

), he will know for sure. On my Anthem, the BIM was located in the basement compartment below the drivers seat (as I remember) but I think it has been in different places in different vintages of the coach. It is a huge power relay that resembles an old time flare (carried in trucks and cars) but shorter. Two big heavy wires coming in and out of the top of the BIM (again as I remember)

Now, on this Cornerstone, I have noted that at times, my chassis battery gets lower than ~ 12.6 (down to 12.4 Volts) without the BIM switching to throw the charge to the chassis batteries from the house bank. I don't know why because I am pretty sure that Don's understanding on this is correct, but my batteries have never gotten too low to kick over the Cummins. All of that worked just fine on my Anthem, but on this Cornerstone, things are a bit less predictable.

Gary

wqmiller · 04-08-2021, 10:32 AM

Ray,

I missed your response! I suspect this may very well be the issue. Will check today. Thanks.

wqmiller · 04-08-2021, 10:34 AM

Gary

Understand! Good input.

757driver · 04-08-2021, 12:38 PM

Quote:

Originally Posted by wqmiller

Trying to help a friend who owns a 2017 Anthem.....the coach is plugged into 50 amp shore power continuously but he discovered the chassis batteries completely dead and after two days of charging with external charger batteries would not take charge. Completely dead. He purchased and installed new batteries. The Vega panel shows the voltage level of the new batteries to be 12.7. That is with the coach plugged into shore power, the voltage remains at 12.7. Question: should the chassis batteries be receiving charge from the inverter charger? The house batteries show charge function is working (13.5 to 14.1). Also when engine is running alternator is applying 13.9v to the chassis batteries. Thanks for any help. Don’t have any electrical schematics so hard to troubleshoot.

Gary had it right. If the chassis batteries are above approx. 12.6v then the house side will NOT provide a charge to the chassis batteries. When the chassis batteries drop below approx. 12.6v then (through the BIM) the chassis batteries will receive a 1 hour charge and then shut off.

On a 2017 Anthem the BIM made by Precision Circuits should be behind a carpeted panel at the rear of the basement towards the passenger side.

To get the chassis batteries to drop in voltage you do not need to unplug shore power, just switch the ignition key on for about 1 minute and then switch off. This should drop the chassis batteries to a voltage low enough for the Magnum chargers to kick in a provide a 1 hour charge. Chassis battery voltage should rise to within a few tenths of what the house battery voltage is showing.

wqmiller · 04-08-2021, 07:58 PM

757Driver

Got it. Good tip on the ignition on to drop the voltage. This seems like a pretty good design for cycling the charge to the chassis batteries. In my London Aire they use a bridge relay to connect the charge circuit and I have learned over time the charge circuit stays energized way too long, in my opinion. That’s obviously another subject for another day. Thanks for the valuable information. I appreciate the help.

I only had a very few minutes to work on his coach today. But found a couple of red leds glowing on the surge protection box. Didn’t have time to get into that today. My friend isn’t able to do any troubleshooting due to health reasons and has recently received a pace maker. I thank all of you great people for the assistance. Will post my final findings. THANKS!!

Gary.Jones · 04-08-2021, 08:22 PM

Quentin

We are all happy if we can help at all. Please do come back and give us the “rest of the story”

Good luck

Gary

cavie · 04-09-2021, 03:05 AM

Quote:

Originally Posted by Gary.Jones

If his friend has a Entegra, then he has two 12-volt chassis batteries and either 4 or 8 6-volt house batteries.

Gary

Learn something new everyday

LWBAZ · 04-09-2021, 12:43 PM

Quote:

Originally Posted by Gary.Jones

The chassis batteries should be receiving a charge if their resting voltages is (I think) below 12.6 volts. If they are above 12.6 volts, then the charging system will not put charge to them until they fall below 12.6. Our Voltage and charge expert is 757Driver and Don will be on here in a few hours and verify the information that I am telling you. I may be a little off absolute but I am pretty close.

The same is true when your friend is running down the road. There is a component called the BIM relay which will mainly charge the house as you travel; but then every so often, it will check the chassis batteries and see if they are up to charge and if not, throw the charger from the alternator to the chassis battery pair (engine start batteries) but only for a specified amount of time (I think it is an hour) before going back to charging the house battery bank.

If you buddy is at 12.6, that is the charge that is about right for a fully charged bank of chassis batteries and there should be no active charge going to them. If there was, they would be getting a voltage around 13.4 volts.

Gary

Gary, you may have been thinking one thing and typed another, but in any case the second paragraph of your post quoted above is incorrect.

When “running down the road”(i.e., driving the motorhome) the chassis battery bank is continuously charged by the engine’s alternator. In this case, the Battery Isolation Manager (BIM) will connect the two battery banks together as necessary to charge the house battery bank.

When you’re parked and connected to shore power or running the generator, inverter/charger will continuously charge the house battery bank (until the house battery bank is fully charged, at which point the inverter/charger will alternate between Float and Off). In this case, the BIM will connect the two battery banks together as necessary to charge the chassis battery bank.