I bought a Turnigy TGY-6S digital cell diagnostic tool to check the voltage of up to 6 cells by plugging the device into the balancing plug of the pack. It worked for a few weeks and nowI get no displays at all. The instructions that came with the unit were useless by the way. Can anyone reccomend a good unit that doesn't cost an arm or leg ? I don't want to use a computer to read it, I just would like to read the indivdual cell voltages at the field after each flight.