Engine will not start because of low battery

[Tommy Gibson]

We are new Beaver owners. We have a 2007 Contessa with 3 year old batteries. Batteries have been fine. While waiting on electrician to install a new 50 amp box I converted down from 50 amp down to 110 and plugged into a standard 110 house plug. I was told by the dealer this would keep batteries charged and refer cold.  My engine will not start today until I boosted and got gen started long enough to start it. Can you help with this? Should this 110 work?

[Jerry Emert]

Welcome aboard!!
Thats exactly what I do and it works fine.  I did learn that I had to plug it in to a 20 amp outlet instead of the usual 15 amp outlet or it would draw too much current and pop the breaker.  My wife hates when I unplug her washing machine for the RV.
Jerry

[Gerald Farris]

Tommy,
Yes, a standard 20 amp house plug will keep your batteries charged if the inverter is set to charge the batteries and your "Bird" system is operating properly, and from your no start complaint, something is either not turned on or inoperative.

First you need a volt meter. Check to be sure that you have 120 volts A/C in the coach without the inverter turned on. Next check the house batteries to be sure that the inverter is charging them when the charge function is turned on. If the house batteries are charging, check the chassis batteries to be sure the "Bird" system is activating the "Bigboy" to charge the chassis batteries.

Gerald     

[Bryan Beamon]

Tommy our 07 Contessa has had similar problems. To test the Big boy battery isolator check the voltage on each side to make sure will using ac power both sides of your Big boy registers over 13 volts. One side reflects charging your house batteries and the other side reflects your chassis batteries. Your bird or diesel bi-directional relay can be activated if your chassis batteries are not showing equal voltage to your house batteries by depressing your battery boost switch. Be sure to check the connection's on top of your Big boy and all batteries. Best of luck ,Bryan

[Joel Ashley]

I won't repeat what others have advised, but would add that it's not uncommon for the connections on the BIRD (bi-directional isolator relay delay) to be loose or compromised, so check those.  If you are not familiar with what we are talking about, the Big Boy solenoid/isolator that physically switches charging or connects battery banks is likely behind the access door between your master on/off switches in the battery bay.  The BIRD module that electronically controls it may be mounted on the inside of the door.

One caution:  turn off or disconnect the batteries if using any sort of tool on the BIRD connections, and don't mis-reconnect them;  full power from the batteries can be present in the module, and you don't want to accidentally short across the closely proximal connections.  I'm not a sophisticated enough of an RV electrician to know if there's potential for harm from the inverter''s charger with the batteries offline, but I'd unplug from the 110v and have the genset off also, just in case.

-Joel