Thor Forums

[Firedog91902]

I discharged the the coach batteries sightly (12.4v) overnight in order to test charging via the emergency start switch. I idled the engine to warm up a bit then locked down the emergency start switch. The voltage of the coach batteries slowly started to rise to 13.3v after 15 minutes. No heat detected in the isolator relay or surrounding wires. The relay's control wires are likely 18 gauge and felt cool. After turning the engine off, and releasing the emergency start switch, I connected the shore power and the coach batteries began charging at 13.7v. Since the the converter is only only a foot or 2 from the coach batteries, and the engine alternator is probably 30 wire feet away, the voltage difference (13.3 vs 13.7) seems normal.

The RV does have a generator, and I have used that to charge the coach batteries while driving. It good to know I have a more efficient alternative. If something bad happens, I'll report back.