I have never had an discharger other what is built into my chargers. The discharger in my 406 Duo is sufficient. I put my batteries into storage when I get home from a day at the racers and it takes less than 20 minutes. People typically get the large resistor banks to cycle their batteries at extremely high current in order to heat them up before a race. The hotter the battery, the lower the internal resistance which results in slightly more punch at the beginning of a race. Personally I've never done this because it shortens battery life.