Brushless electric wrench is not tight, what's the matter?
DC motor commutator (Tan Shua) wear seriously, high current can not effectively let the motor work. If the machine is a burst, consider one of the batteries in the battery, the drive circuit board is usually very little problem. According to my experience, the battery pack accounts for forty percent of the machine's performance.
Manifold. 1, the battery degradation, internal resistance to large, full work when the high current can not be put out.