Generac Fire, Pulsating Lights and Overbright Lights

We are taking another hammering – this time from snowstorm Q. We had a blizzard two weekends or so ago and for the first time in the history of our 24 years in NH we did not lose power. Typically, a squirrel farts three towns away and we have to run the generator for five days, but we have a serious blizzard (Nemo) with 30 inches of snow and we did not even lose power. See PSNH, it pays to be proactive and cut back the trees in the summer. This time, the high winds actually helped keep the snow from weighing down trees like the storm we had back in October 2011.

We have a 7.5K generator that I bought a few years ago and I was prepping it to make sure it was in good running condition. It came with a battery charger, but it was like an adapter-style charger like you would have for cell phone or laptop, if that makes sense. It plugs into an outlet just under the start button.

It is a maintenance-style charger though and meant to leave plugged in to ensure the battery is always at full charge. Instead of using this charger, I took my battery tender that I use for the motorcycle and hooked it up. Black to black, red to red. Then I plugged it into an extension cord and put the cover over the generator so the charger was under the protection of the cover in case it rained.

After about 20 seconds, I smelled something similar to a burning ballast in a fluorescent light. I pulled the cover off and there were flames coming from the battery! In case that was not bad enough, I had just filled the 5-gallon gasoline tank, which sits directly over the battery which was now shooting flames about 6 inches all around it.

I panicked and unplugged the cord for the trickle charger, and slapped the flames out with my bare hand. Surprisingly, the battery was barely damaged on the outside. But there was smoke pouring from the control panel now. I ran into the house and grabbed my fire extinguisher and put it out. When I pulled the front panel off the control panel where all the outlets and switches were, I found the reason for all the smoke. There were a LOT of wires that used to have insulation on them that were now bare copper.

Now the day before the huge blizzard hit, in an effort to be prepared for losing power, I fried our only source of backup power.

Generac 7550 EXL Positive Battery Terminal

And for all of you well-meaning people who have suggested that the wires on the trickle charger were hooked up backwards and that is what caused the fire, I would like to show you the corresponding Battery Tender Plus cable clamp. I am definitely an idiot, but I am not stupid. I have done this since we purchased the generator and it has always worked perfectly.

Battery Tender Plus Positive Cable Clamp


Generac 7550 EXL Top Rectifier of Stacked Rectifiers


Generac 7550 EXL Bottom Rectifier of Stacked Rectifiers


Generac 7550 EXL 10 AMP Fuse to battery POS terminal


Generac 7550 EXL 10 AMP Fuse


Generac 7550 EXL SCB/System Control Board (upper left in panel)


Generac 7550 EXL SCB/System Control Board rear (removed)


Generac 7550 EXL SCB/System Control Board ASSY #83970 REV U


Generac 7550 EXL Switch Wiring


Generac 7550 EXL Outlet Wiring


Generac 7550 EXL Rewired (Green Arrows)


Generac 7550 EXL I have no idea what this is


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