Thor Forums

[javelin]

Just to clarify, coach and house batteries are usually the same thing (batteries for lights, water pump etc.) and the chassis battery is the one that starts the engine. So I think you are saying that while the engine is running and you are not on shore power; chassis connect switch is on....the chassis battery reads 14VDC on your voltmeter, but the coach batteries read only 12.0 VDC (which is essentially 25% of full charge). My 2013 ACE has separate coach and chassis battery disconnect (controls BCC latching relays) switches by the door not just one “use/store” switch.


On another post I provided a link to the RV Custom Products manufactured BCC (Battery Control Cabinet) which included a schematic and full description of operation and troubleshooting info. I am not sure if your 2013 Daybreak uses this BCC like many other 2013 Thor class A gas coaches do? If not you can ignore the following:

If it does, you may have a failing interconnect relay (the one that connects chassis and coach batteries together (when emergency starts are required or under normal charging conditions when the BCC tells it to close). When engine is running (chassis battery latching relay is on) ; chassis battery is charging from the alternator. When the chassis battery hits 13.2 VDC the BCC closes the interconnect relay which then allows the alternator to also charge the coach batteries. Similarly when parked; on shore power; engine is off and coach battery latching relay is on; the coach batteries are charging from the converter. When the coach batteries reach 13.2 volts, the BCC closes the interconnect relay which allows the converter to now also charge the chassis battery.


If not the interconnect relay, you may just have a poor/loose connection somewhere in the charge path anywhere from the chassis battery connection at or inside the BCC to the coach batteries. If you have this BCC, changing latching relays or the interconnect relay inside will be “fun”. Take care if you work in the BCC. Disconnect all batteries; shore power etc if you are doing any major tweaking in there or you will be cooking more than turkey.