Batteries

[pfjw@aol.com]

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

 

[AlfySande]

pfjw@aol.com;3634287 Wrote:

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 ver
nearly crapped-out battery may have enough to blow a fuse i
dead-shorted. Fuse action is not voltage dependent (as long as the fus
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 cause
the electronic controller to draw too much current in an attempt t
maintain speed.That's just a guess, though. It is hard disagnos
something with no information


--
AlfySande

 

[Ron D.]

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.