http://www.hangtimes.com/chargers.html Scoll down a bit and you will find it. $39.99.

I use the voltwatch on my nimh battery planes. I use the voltmagic on my A123 equipped EF Yak. It really works wonders and after the first day of using it the price became irrelevant.

You can adjust it for your set up and the info it produces is truly useful.

The voltwatch is an onboard volt meter, the voltmagic is an onboard computer. Really take the time to read what it does, it could save you a plane.