Our MEP-1050 generator came with two Optima red top AGM batteries, one of which was marked bad. The good battery had about 8 volts in it and the bad battery had 3-4 volts.
These Optima batteries sell for $300 – $374 each depending on where you look so I searched to see if there was a way to save one or both of them.
I found a guy on YouTube who demonstrated a Noco Genius 5 battery charger that had a repair mode and he was able to fix a dead Optima battery. I don’t have a Noco Genius 5 but you can find them for around $65. I have another inexpensive charger already so let’s give it a go. If it’s already broke I can’t break it more I guess.
I was able to get the battery that was not marked bad to take a charge with my charger. The battery marked bad would not take a charge at all and my charger didn’t even try, just blinked like it was done charging.
I connected another good battery to the bad battery with some heavy duty jumper cables and after an hour I was able to measure the voltage in the bad battery had gone from 4 volts to about 8 volts. This was encouraging. So I connected my charger and known good battery to the bad battery like this:
After a few more hours I was measuring 10 volts on the bad battery. The known good battery warmed up a little but never got hot so let’s give it some more time connected like this. A few hours later I was up to 11 volts and neither battery was getting hot. It’s getting late so I left everything connected as shown overnight. In the morning I had 12 volts on the bad battery so I left it charging for another 12 hours and got up to 12.8 volts so I tried to see if the charger would recognize and try to charge the bad battery without the good battery connected, which it did. I left the bad battery on the charger another day until the charger displayed full.
Connecting both Optima batteries in the MEP-1050 and I can fire up the display and hear the fuel pump when going into prime mode. Success!
One item to check off the list of things that need doing to get our MEP-1050 generator running. Next will be replacing the bad 80 Amp circuit breaker.