Thanks, I'll check out my local Napa. And yes I'll be careful

 

If going with solar,deltran and others have a management device that gos between power source and battery. It will not manage less than a certain wattage but would be better than relieing on a low watt non controled charge. I don't see why lighter would be part of power train management,although unclean or excessive voltage supplied thru lighter would imperil pcm and electronic components same as if power was applied at battery. You have a valid point regarding need for more than 5watt or so in cold weather and extended periods.

 

This panel is about 1 ft square and max output voltage in bright sunlight is 13.2 volts and about 1.5 watts. The cig lighter is a direct link to the battery bus so the output goes directly onto the bus which in turn will charge the battery. Stay alive wattage for most of the components is only about 100mills for the memory units in things like the pcm and radio. Result is a net gain in battery charge. It will not charge a dead system but it does maintain and help top up the charge in the system. 13.2 volts at about 800 mils is not going to hurt any battery system. It is an easy and cheap way to maintain the batteries.

 

This can be had for $20 at Harbor Frieght...I plugged mine in today (I've had it for about a year just never used it before).
http://www.harborfreightusa.com/usa/...ubmit2=find+it

 

You are going to like that battery maintainer. I use my truck around the property a lot and would drain the batteries until the truck didn't have enough juice to start. Since starting the maintainer, the truck pops off even in cooler weather without a problem.