[oldtech]

While taking the battery inside might very well allow starting the next morning,something to consider is how practical this will be. Depending on the vehicle,it may well have dual batteries,neither of which will be particularly easy to remove/replace at -40F. I’ve done this before under those conditions w/satisfactory results,but it was a gas car w/ single battery.

[Kenny Bunk]

Done the hot coals under the crankcase thing. Works. Of course, bein' in your "gay state," lettin' a couple of the local Reggie/Barry lashups sleep under the truck might ... just might ... work just as well.

But listen up, run down to Pep Boys and get a block heater. That's what they are for.

[Bulwyf]

most diesels are dual battery.