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AlfySande November 21st 16 06:54 PM

Quote:

Originally Posted by (Post 3634287)
On Monday, October 10, 2016 at 11:06:50 AM UTC-4, Phil Hobbs wrote:

Torque is proportional to current, no?

Yep. But a DC motor dead-stopped is a short circuit. And even a very nearly crapped-out battery may have enough to blow a fuse if dead-shorted. Fuse action is not voltage dependent (as long as the fuse is rated at a higher voltage than the application).

Peter Wieck
Melrose Park, PA

Hi...i am a new user here. As per my knowledge the bad batteries caused the electronic controller to draw too much current in an attempt to maintain speed.That's just a guess, though. It is hard disagnose something with no information.

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[email protected] November 21st 16 08:10 PM

Batteries
 
On Monday, November 21, 2016 at 2:17:10 PM UTC-5, AlfySande wrote:

Hi...i am a new user here. As per my knowledge the bad batteries caused
the electronic controller to draw too much current in an attempt to
maintain speed.That's just a guess, though. It is hard disagnose
something with no information.



I think you left out a step:

a) The batteries ran low.
b) The user kept 'upping' control to maintain speed.
c) As long as the motor is turning, things are (mostly) OK.
d) The motor (brush-type) stops dead, but the speed control is still on MAX.
e) Now the full - remaining - battery capacity is going through the fuse.
f) *POOF*

But, the batteries are sulphated, the speed controller has been overheated, the motor overheated - or at least those commutator contacts arced. Altogether a mess.

Any properly designed system would have a condition meter and a low-battery cut-off to prevent this. And a thermal breaker in addition to the fuse.

Peter Wieck
Melrose Park, PA

Ron D. November 23rd 16 04:03 AM

Batteries
 
What fuse is a good question.

Is there a possibility that the "wrong battery type" was put in the buggy? i.e. a battery that does not like deep discharge replaced for one that would. A "car battery" pretty much would die quickly if it discharged too far.

A defect with the charger is another possibility. Loose connections can kill the electronics responsible for charging.


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