Back to lipo's! Brushed or brushless. Lipo's are different from NiMh. NiMh could be disharged .09-0v. Lipo's discharge 3v each cell, At 7.4v lipo's, lipo should NOT be discharge 6v altogether. For longevity of lipos. Good ESC should have Cut-off voltage, or dischaged by time.
Remember, it's important, NOT to overdischarge lipo pack. Rule of thumb, NOT to discharge them below 6v on an 7.4 lipo pack, 9v @ 11.1v lipo,and so on.
IF, ESC like TekinsRS/RSPRo can customize cut-off voltage at 6v - 6.50v, My rSPRO is set at 6.50, w/7.4v lipo, and 9.6v w/11.1v lipo. with no problems arising. My lipo are 9 month old, and raced every two weeks.
Its very easy to destroy a good lipo pack by overdischargeing them.
Good Luck with lipo's!!! Haven't used NiMh's in 9 months. Lipo are the future of RC's. Just use the correct charger, and use the rule of thumb on discharging.