Originally Posted by
WIGMAN
There are plenty of people charging at 2 and 3 C, most are stock racers, pros don't need to charge higher cuz if they want more they can boost or drop a wind. In blinky classes voltage is everything, charging at a higher amp will increase performance.
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I do know some oval racers that charge at 3-5C, those oval guys are nuts, but in oval voltage is king, every little bit helps when you are searching for how to make your car a hundreth of a second faster per lap, if you can find a tenth of a second in oval everyone thinks your cheating.
Danny has said more than once that the only reason charging at higher amps gives more performance is that it heats the battery. He has said that if you charge a pack at 1C and another at 5C and let the warmer one (5C charge) get to the same temperature as the other one, they will perform the same on the track.
The oval guys are charging at high C rates because it is the only legal way to warm the pack before racing, but it depends on perfect timing to have the pack ready just as your heat is up or the benefits are lost.
I have heard that BRL (Brushless Racing League) has come up with a way around this to discourage the high amp charging: they require the car be in tech at least one heat before you are up to race. So the benefits of high C rate charging tend to be reduced because the pack has an additional 8 minutes to cool down.