I finally purchased & received my TH-50 heating pad.
The question is where is the best place to install it?
I have a 8kw Modal 0056100

I also picked up the TC-2
That will power the pad & blanket around the battery.

We (the company I work for) don't push any of the cold weather add-on's. I don't have an issue with a block or oil warmer but warming the battery is another matter. Given the history of battery charge problems and terminal/post oxidation I personally do not use battery warmers. The battery in the generator is always maintained by the charging system and will keep it ready even in severe cold, with the use of 5w-30 synthetic oil we experience no problems with the engines cranking. As far as the TH-50, try to stick it to the engine block as low as possible.
Dick from Canada
We have an older model CorePower unit that came with a battery heater and engine oil heater.  The battery heater had to be replaced once because of moister problems .   If it should fail again it will not be replaced.  As posted by 78buckshot  the use of 5w-30 synthetic oil and a oil heater should work just fine. Synthetic oil will flow even at -40F  . My car sits out during the winter and starts without grief even at -25F . 
I too have stopped selling the battery heaters, but firmly believe the oil heaters are great for cold starts. I can hear a real difference in the starting on the heated units. The battery heaters fail too many times. And when they fail, they tend to take out the fuses that sense current to the generator and that starts the generator. I think a battery wrap like the liquid cooled units use is far superior.