Charging house batteries

[Laurel Moore]

I know that the isolator relay and the big boy controls the battery bank to charge. But I have never seen  every charge system to all quit at the same time. My house batteries are not being chargedby shore power, generator, alternator. I have a 2009  beaver contessa, intellitec mod. 700 energy mgmt system.thanks in advance for any input.

[Steve Huber Co-Admin]

Laurel,
Couple of things to check.
-First, verify you don't have a bad house battery that is preventing them from charging.
-When on shore or geni power, check voltage on each of the 2 large terminals of the Big Boy. One is house and other is chassis batteries. If it's working you should have same voltage (~12.5-13.5v) on both. If there is =>12V on one terminal but not the other, either the BIRD or the Big Boy is bad. IF the BIRD is working you'll have about 4V on the solenoid terminal.
-Check the large fuses (60 to 200A) in the rear electrical bay.
Steve

[Laurel Moore]

Thanks Steve, I will check it out tomorrow. All of the large fuses are good.

[Joel Ashley]

It’s not unheard of for the connectors on the BIRD to corrode or work loose, so that’s easy enough to check also.  And of course all battery posts, but more so the ground at the chassis.

Joel

[Gerald Farris]

Laurel,
If you house batteries are not being charged when plugged into shore power and there are no bad fuses, either the charge function on your inverter is turned off or your inverter is malfunctioning. The inverter is wired directly to the house batteries, and it should charge the house batteries regardless of what the "BIRD" system is doing.

On your coach the engine alternator is wired to the chassis batteries and only charges the house batteries through the "BIRD" system, and the inverter is wired to the house batteries and only charges the chassis batteries through the "BIRD" system. Therefore, if the engine alternator is not charging the chassis batteries or the inverter is not charging the house batteries, the "BIRD" system is not the problem.

Gerald

[Joel Ashley]

On reflection, Gerald makes sense.  Even if the BIRD or Big Boy solenoid were awry, the alternator would still charge the chassis set and the inverter the house set. 

But you say the alternator does charge the chassis ones... only the house set isn’t getting input from any source. 

Joel

[Gerald Farris]

Laurel,
I just reread your question, and I noticed that I had missed the part where the engine alternator is not charging the house batteries either. If the engine alternator charges the chassis batteries but not the house batteries, that is a "BIRD" issue, but for the failure of the house batteries not charging from shore power or generator power, that is an inverter problem that has no connection to the "BIRD" system.

Gerald

[Laurel Moore]

Gerald,alternator will charge the chassis batteries.  So when the battery volts drop below. 12.5 and shut down the lnverder , what charges the battery bank up to open the inverter?
My batteries are 2 yrs old so I did not suspect them. Looks like I have one with a dead cell,will replace it  and then see where we are at., thanks. Laurel

[Laurel Moore]

Gerald, received your note, looks like I have 2  problems, I will let you know.

[Gerald Farris]

Laurel,
If you are on shore power or if the generator is running, your inverter should recharge your house battery bank. If not, either you have the charger function disabled (turned off), or the battery charging section of your inverter is defective.

Sometimes, you can disconnect all power (12 volt and 120 volt) to the inverter for about 30 minutes and it will restart and function properly, especially if you have a Xantrex inverter. That is rare for a battery charger malfunction, but it is a easy fix if it works.

Gerald
 

[Laurel Moore]

Gerald,
I have magnum 2000 inverter  the manual shows that it goes into fault at 12.5 battery volts.

[Gerald Farris]

Laurel,
I think that you are miss reading the manual or you have the wrong manual. Any RV inverter that will not function below 12.5 volts would be almost useless. It sounds like you need to call Magnum technical support, and they can walk you through trouble shooting the battery charging portion of you inverter.

Gerald