If you are looking for an inexpensive dedicated LiPo battery balancer, don't overlook Astro Flights Blinky. It will balance 2-6 cell LiPo's, either while charging, or independently after the charge, or even after a flight. It also warns if there are any cells in the pack that are below 3.2 volts.
I have been using the Blinky for over a year now and can't get over how well it works. If you are getting into electric flight and already have a good LiPo computerized charger without a balancer, the Blinky is the affordable solution.