> When I've lived in extremely cold locales, experience taught me that I had
> to bring my battery in at night, and plug in a block or dipstick heater.
> That is, if I wanted it to turn over in the morning so I could get to work
> on time.

This sounds like 6V days, eh?  My '61 splitty had a brand new
battery one Xmas in NoDak, 1964.  It was 38 below at night, warming
to "only" 18 below in the days, short as they were.  I had 20 W
oil from Colorado winter.  The new battery turned the motor over
exactly 4 times.

The dealer put 5W oil in it, plus the common (then) sump heater.
No problems then!

I still have a bolt-on sump heater for my '81 Vanagon, but I
stay away from NoDak in the winter.

Richard