TrakPower has some good Lipo info here Mike & should answer most of your questions.
http://www.trakpower.com/index.asp?page=lipoExpert.asp
I am considering a 2nd budget charger myself and found out rctech member Bulldawg R/C has TrakPower Lipo chargers for $60 + shipping. Seems like a great deal, and small size makes it nice too.
http://www.bulldawgrc.com/trpitpro50li.html