At coffee this afternoon with another retired old co-worker, we were recalling a winter in the late '75s, when we had a two week cold snap that lasted two weeks with night time temps ranging from -30 to -50 F.
Not trusting just the block heater, I also had a 150 light bulb next to the battery, (but not touching it), and a thick felt blanket over the motor to keep as much of the heat.
One morning, one guy who's car wouldn't start an I had to boost, asked me about the light he had seen under my car.....I told him about it and warned him about not letting the bulb touch the battery...
The next morning, when his car still wouldn't start and since he didn't have a blanket, he hadn't taken the light out yet...
When we lifted up the hood we found out the stupid plick had used a flood light and had melted the battery side.
The new battery he had to put in didn't give him any more starting problems:smile: