[Archived]

Hooking up two 12 volt chargers definitely charges the batteries, even though they show different SOC, they eventually get to 100%

I tried the other method, one 12 volt charger hooked up to the Vanner. Red to 24 volt, black to 12 volt. 4 hours later there was no difference in the reading.

**Wondering why we wouldn’t hook the RED lead to the 12 volt connection on the Vanner and the BLACK lead to the common ground, it seems like that would be a complete circuit?

[Jon]

Our Liberty has a dedicated 120VAC circuit/breaker with receptacle on the roof of the engine bay for charging the chassis batteries. In 1999 Liberty installed a massive 24volt DC charger and hardwired it to the Vanner (I think, maybe the Isolator?) on the roof of engine bay plugging it into the above referenced receptacle. For 1999 it was probably high tech, but Jeff Rowe at ETLC told me to get rid of it as it was a dumb charger and could overcharge, damage the chassis batteries, and boil them out.

A year after buying our coach in 2014 I replaced the big charger with a Guest/Marinco charger and hardwired it into the chassis batteries. I don’t leave it on all the time. If the coach has sat for a month or more, before starting the coach I’ll turn the key to “ON” and check the “Engine Voltage” on the dash gauge. If I don’t have at least 24.5 volt DC, I’ll turn on the “24 Volt Charger” breaker on the main panel to bring the chassis batteries up further and then fire up the Detroit. Sometimes I might leave the outside lights on overnight and drain the chassis batteries and need to bring them back up.

I’m reluctant to leave the Guest/Marinco charger on all the time as I think it would mask a battery going bad and suddenly be so bad that I can’t charge the chassis batteries or start the coach (BTDT!). I’ve found that the chassis batteries “stay up” for a long time if I don’t leave “something on”.

There are other alternatives to the Guest/Marinco chargers that other Prevost owners have used. I like the idea of having the charger hardwired on a main panel breaker. Easy to turn on and off. Don’t have to drag out a charger hook it up during inclement weather.

Somewhere I have a wiring diagram that I used and if I can find it, I’ll post it.

https://www.marinco.com/en/p/2720A/Guest-On-Board-Btery-Charger-20A

[Dick]

Thanks Dick!