We had a cold snap here in Toronto and the wife couldn't start the 85 300TDT and I went out and tried my diesel truck and could hear it was not going to start. Our first problem was they were not plugged in, but the other problem is that the battery capacity falls as the temperature goes down. I was thinking of wiring a trikle charger up to the block heater plug so that when you plug in the car you plug in the charger as well. Does this make sense or would it be waste of time? The truck has a good block heater so it may not be worth the effort but the Benz has an aftermarket pad heater on the oil pan that doesn't work great.

Thanks