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simibill
09-27-2005, 04:57 PM
I was doing some bench testing of my motor and servo centering and I forgot to disconnect my 3200mAH LiPO pack resulting in a defunct pack. I knew better but just forgot, which brings me to my question. If the ESC has voltage cutoff why didn't it protect my pack? There ought to be a better way...

stanger89
09-27-2005, 05:10 PM
Because it cuts off power to your motor but maintains it to your other electronics. The reason is that if it cut of everything, you'd loose control of your plane when your ESC reached cutoff.

The logic is that, the servos et all, use a minimal amount of power compared to the motor, so even when there isn't enough "juice" left in the pack to drive the motor there's plenty to drive your electronics for the short time it takes to land safely.

The last thing you want is for the ESC to cutoff your flight controls, as it would be much worse to loose a whole plane than "just" a battery pack.

timocharis
09-27-2005, 07:46 PM
http://loseloose.com/

simibill
09-27-2005, 09:22 PM
I understand that the ESC is supposed to retain some power for the receiver and servos to operate, but why didn't it cutoff when voltage was down to 3.7? I think this only applies when the motor is operating.

stanger89
09-27-2005, 10:35 PM
It probably did cutoff "the motor" when it hit 3.7. Like I said, from a safety standpoint, it would be very bad for the ESC to ever cutoff power to your flight controls. It has no way to know if you're in-air or not. I know it sucks in this instance though.

What would happen if you were flying, and somehow, with the stick at idle, the battery dropped below the cutoff. The motor would not be operating, but if the ESC cutoff the voltage, you'd loose your flight controls and loose the plane.

IMO it's better to loose a battery than a plane. Flight controls should never, ever be automatically cutoff, for any reason whatsoever.

timocharis,

I'm a looser and I'm prooud oof it. :D

GeraldRosebery
10-04-2005, 12:58 AM
I was doing some bench testing of my motor and servo centering and I forgot to disconnect my 3200mAH LiPO pack resulting in a defunct pack. I knew better but just forgot, which brings me to my question. If the ESC has voltage cutoff why didn't it protect my pack? There ought to be a better way...

There are a lot of expensive lessons in this hobby, having done it for over 33 years. This is not your last one, believe me. What I try to do is set things up so that I only do really dumb things once.