Need help with electrical issue

[Capt’nKarl]

2018 R-23 with 2 house, 1 engine and 1 thruster battery. Lost shore power to the boat a couple of days ago and battery voltage dropped below 10.8 volts. After fixing the shore power issue the batteries charged up to normal. With only the house battery switch on I happened to notice I had no power going to the CO detector in the 1/4 berth and no power to the high water bilge alarm ( I think, that’s all I’ve found). According to the instructions on battery configuration you have to reset the charging relay by switching on the parallel while the engine is running or plugged into shore power. Here’s the issue. While ON shore power Switching the parallel to the on position powers up the CO alarm and the high water bilge alarm but as soon as I turn the parallel switch off I loose power to both. I’m not sure what I need to do to “reset the charging relay”. Or is this boat meant to have the parallel switch on all the time? Any help is appreciated.
Karl

 

[knotflying]

There reason for the parallel switch to be on is to charge up the batteries that are below the relay threshold to kick in. Once the batteries are charged properly everything should go back to normal. Your batteries that were at low voltage will falsely display a full charge once the charger is on. However if you then turn off the parallel the voltage will drop and the relays will kick off. So make sure your dead batteries are really charged before turning off the parallel switch. The parallel switch should always be off unless you need to jump between the engine and the house batteries.