realy for racing most are charging at 6A. the important part is not to let the cells get too hot. monitor them and have them peak around 125 to 130. I usually stop charging at 125. If you watch the temp it will rise to about 130-132 even after you stop charging. for a 6 cell pack on a t35gfx I have it set at .03 delta. but have a temp guage with an alarm at 120. I have 3800 that are about 9month and still take 4100-4200mA