Thanks for all the info guys.
Yes, immediately after starting the engine the battery drops tp 11.9v to 12.0 v and stays there for several minutes and the alternator gets very hot to the touch.
A few minutes later the batteries start showing normal charging voltage, 13.9 or more.
So is the heating within the engine controlled by a set time or is it by temperature?
Where do I find the heating coils, and if I disable them does the battery then receive charging immediately the engine is started?