A tray style discharger like a trinity Real Time is exactly what it looks like. It discharges each cell individually on its own little lightbulb. Currently, Novak is making one that will include a cutoff for each cell, but for now just unscrew each cell when the light is almost out. It discharges by using a resistor attached to a light bulb then attached to a screw. Just set your pack into the tray and screw all the screws into the batteries and the lights will come on. I'd wait for the NOVAK discharger, it looks pretty sick and has a cutoff built in so you don't have to watch the lights. Check your LHS first, then look around at tower hobbies. Integy also makes a good one.