Community Forums

cpp8284 · 01-11-2022, 03:49 PM

We have a 2019 Vista LX that we recently purchased. I'm having issues with the inverter quickly discharging the batteries when it is turned on. The inverter is a Maxum with the ME-MR remote control. When I unplug from shore power and turn on the inverter, the digital display shows the battery voltage decreasing rapidly from 12.5 volts until the low battery alarm shows within a short period of time. The display seems to show a current load of 34 amps. I can't imagine what is causing a load of that magnitude. I've gone through the setup menu on the remote control and everything is set to the default settings. I would appreciate any advice about how to find the problem.

Ron Postma · 01-11-2022, 06:34 PM

Check the breaker on the "Magnum" inverter and the breaker in the AC distribution panel. It sounds like the charger is not getting AC power. This means it can not pass the shore power to its loads and run the charger running the inverter to power its loads. What is displayed on the remote.

twinboat · 01-11-2022, 07:55 PM

34 amps 12 volts DC is 3.4 amps 120 volts AC.
Not a big draw, could be the fridge or something like that.

If your batteries are showing 12.5 volts, they are already slightly discharged. They should be at 13.4 volts on shore power.

I will guess that the batteries are shot. Have you checked the cells for proper water levels.

cpp8284 · 01-14-2022, 01:19 PM

Thanks for the input. The cells are dry and the batteries are dead.

Buying 4 new Interstates.

I would like to install a battery disconnect switch so that the phantom loads don't discharge the batteries when in storage without power connected. There are two connections to the positive terminals on the batteries leading to different places. Does anyone have any idea where the cables go and which one should have the disconnect switch?

DancinCampers · 01-15-2022, 12:33 PM

My guess one goes to the inverter, the other to a solenoid controlled by a disconnect switch by the step well.

weirba · 01-18-2022, 04:37 PM

I would think you need disconnects on both, but what about the ground? would it not accomplish the same by disconnecting the one ground?

Also, I am curious if it is a 2019 coach you should not have to replace batteries yet, maybe you should consider glass matt, or gel with little or no maintenance required.

cruizerEd · 01-19-2022, 04:08 AM

Quote:

Originally Posted by DancinCampers

My guess one goes to the inverter, the other to a solenoid controlled by a disconnect switch by the step well.

DancinCampers is probably right. There could be two or three hot leads running from the battery.

On ours one goes to the inverter and the other goes to a disconnect switch.

When you use the button to turn off the coach the disconnect switch is opened and signal is sent to the inverter to turn off.

To add a battery disconnect switch you will need to add a bus bar and a big switch.

I used a 600A BEP because in theory the inverter could pull 350A and the batter boost 250A but a 400A will probably do. If you use their pro install series you can make a very tight implementation.