Was talking to a friend that has a Ford PSD and he has added an on-board battery charger. It's the small trickle charge type that you can get at most any auto store. He wired it in parallel to the block heater. Whenever the block heater is plugged in, the charger keeps the batteries topped off too. Sound like a good idea to me but would like more input.

 

Had this and a small electric heater for the interior on one of my old cars. Really nice to get into a car thats warm, battery full etc. UJust got to be very careful that you install the stuff correctly. (Indoor use! doesn't like water)<br>AlpineRAM

 

Never had one on a P/U but they are on all of our Firetrucks.<br>They sit inside but have radios, flashlights, ect.pulling on them 24/7 the chargers work great to keep the batt maintained.<br>I've thought of putting one on mine.<br>You can go through any comercial truck or firetruck builder and get the co. that produces them and spend small or big bucks. Just depends on what you want.<br><br> : Eddie : 8)