My car is POS 91' Honda Accord and it has a electrical leak somewhere I think near the fan circuit.  Seeing as I paid $1100 for this car in 2008 I see no reason to drop a few hundred bucks to find and fix the issue.  Electrical gremlins are tough to trouble shoot. After getting off on a Friday and not driving the car all weekend during the winter the car didn't really start on Monday mornings. I dread going put there and finding out it was dead which was often.  So I bought this in hopes that it would keep the battery charged so that it would start.  It's an easy hook up to the battery and just shoved the box next to the battery and strung the plug out the front under the hood.  Ran an extension cord from my outside electrical box and plug the car in every night after work. Has yet to fail me.