Battery charging help

[Old Bounder]

Way to go....... Good show.....

As you discovered, the only reason for the "lock out relay", used to open the isolator when both the alternator and generator are running, is because the voltage from the converter would sometimes be higher than the alternator voltage and it would confuse the alternator/regulator and dash gauge.

As you correctly stated, it makes sense to open the isolator when the natural charging sources are available to each battery anyway.

[Fred Cooper]

Originally Posted by AF4J

Well that fixed it.
Just in case someone else has the same issue, here is how to wire the battery isolator lockout relay correctly (unless mine burns down next trip).
First you need a 5 pin relay, some are 4.
30 pin receives power when ignition is turned on.
85 goes to ground
86 is hot when gen set is running and shuts off isolator, hence "lockout relay".
87A the normally closed pin goes to the isolator delay.

When the engine is on, ignition sends voltage through relay from 30 to 87A which is normally closed and closes battery isolator then charges house batteries. The delay involved does just that, delays it to give the starting batteries time to charge back up before charging house.

When the gen set starts, with the ignition on, it sends voltage to pin 86 on the relay and opens the battery isolator solenoid, I guess since at that point the converter charger will charge the coach batteries.

Thanks all for the help!!

Thanks for the detail about how it works. I'm still exploring the operation of my isolator delay. My coach is a Holiday Rambler, but should be similar. Was the "battery isolator lockout relay" you described a monaco installed relay, or did you add one?
Thanks

Fred

[AF4J]

Fred these are all Monaco.
The delay is pretty simple, has 3 wires and one is ground, once the lock out relay has sent power via the blue wire to the delay and if the voltage is above 13.5 (could vary a bit) it sends voltage via purple wire (another purple tied to it coming from dash aux start switch) to the isolator solenoid and ties all batteries together, thus charging all start and house from the alternator. Or if aux start switch is held it bypasses lock out relay and delay for start assist.

[AF4J]

Also Fred, I have noticed a lot of my circuit panels have HR on them. I assume that is for Holiday Rambler. All the relays, delays, and solenoids are in the right rear with the battery disconnect switches, the door usually has a schematic on it identifying most of those components.

[AF4J]

Loulong, Thanks!! It also fixed the next problem to tackle. Why my alternator light and tach didn't work when the generator was on....