MEP 831: Won’t Start and Batteries Seriously Overcharged

[Lostranger]

We use a pair of 831 generators as primary backup for an off grid solar home. The main unit has been down for a few months. For the past three weeks, the backup unit has been hard to start. Acted like weak batteries. Today it would not turn over. When I pulled the two batteries to clean the cables and connectors, one battery read 15.2 bolts on a good meter, and the other read 15.3. These are lawn mower batteries stacked inside the case and wired series. What would cause this unit to overcharge?

TIA
Jim in NC

 

[DieselAddict]

You need to check the output of the power supply in the unit. That is the only thing that provides the DC power for the unit when its running.

 

[Lostranger]

Thanks, Chris. I’m gonna drag it out of its shed in the morning so I can reach the pull rope. Assuming I get it started that way, where do I check the output you mention?

 

[DieselAddict]

The power supply is a rectangular box inside the engine compartment on the left. When you look at it the wiring should be pretty obvious.

 

[Guyfang]

There is also a procedure in the TM to explain it. It's not hard.