Hello, I bought a log of 20 of MG966 servos on eBay. the quality of them are very uneven. Serial of them, when they reach one end they stop but Draw almost 1A of current. Why is that? The only thing I can think of I the tiny circuit inside the servo isn't working properly.
If you are driving servos right to their end stops then you are stalling them. They always draw a lot of current when they are stalled.
Since stalling a servo is something you really really want to avoid I wouldn't worry too much about how current they take when you are abusing them like that.
slipstick is correct, but it could be as simple that they are production rejects - not necessarily bad.
Perhaps the feedback adjustment or pot ‘position’ on the output shaft needs to be trimmed, or simply you are driving them beyond their designed angular limits.
The drive pulse timing is well explained here...