pretty sure i just got this one from my brother. it was on clearance for 20 bucks.
http://www.tractorsupply.com/en/stor...r-101588799--1 my brother does some good research on who makes stuff. it turns out that this charger is the same brand we had as kids. and lets say it got left in the rain, ran over a few times, still left in the rain, the metal cover was then gone, still in the rain, and guess what? it still worked for year on end.

he has 2 of them, one for each house.