Mobilty scooter power chair will not move.

[B Squareman]

Mobility Elite scooter power chair will not power the motors
with the control knobs. No sound, nothing. The chairs will go up
and down via a second control knob that is not connected to
the electronic control unit. Switching the power on will show
the LED power meter blinking (not sure what that means.)
Charged for 4 hours, the power meter level is at orange,
between red and green. Both 12V batteries read 11.9V with
the meter indicator at orange.

The control unit is insulated inside what appears to be a heavy
duty cast iron housing. Looking around for the model number I
find only "Made in England." If this may help, see a glimpse of
this $2000 similar scooter here.

http://supportsusa.com/mobility/powerchairs/tango-elite.htm

What part of the circuit is best place to start looking for
the problem?

Thanks

 

[Ross Herbert]

Mobility Elite scooter power chair will not power the motors
with the control knobs. No sound, nothing. The chairs will go up
and down via a second control knob that is not connected to
the electronic control unit. Switching the power on will show
the LED power meter blinking (not sure what that means.)
Charged for 4 hours, the power meter level is at orange,
between red and green. Both 12V batteries read 11.9V with
the meter indicator at orange.

The control unit is insulated inside what appears to be a heavy
duty cast iron housing. Looking around for the model number I
find only "Made in England." If this may help, see a glimpse of
this $2000 similar scooter here.

http://supportsusa.com/mobility/powerchairs/tango-elite.htm

What part of the circuit is best place to start looking for
the problem?

Thanks

Could be the battery itself or the charger or both, or even the
controller (check out the first two before suspecting the controller).
You need to have it checked by a competent repair tech if you are
unable to carry out the necessary testing yourself.

 

[Jim Yanik]

Mobility Elite scooter power chair will not power the motors
with the control knobs. No sound, nothing. The chairs will go up
and down via a second control knob that is not connected to
the electronic control unit. Switching the power on will show
the LED power meter blinking (not sure what that means.)
Charged for 4 hours, the power meter level is at orange,
between red and green. Both 12V batteries read 11.9V with
the meter indicator at orange.

The control unit is insulated inside what appears to be a heavy
duty cast iron housing. Looking around for the model number I
find only "Made in England." If this may help, see a glimpse of
this $2000 similar scooter here.

http://supportsusa.com/mobility/powerchairs/tango-elite.htm

What part of the circuit is best place to start looking for
the problem?

Thanks

11.9V is too low for charged Lead-acid batteries.It should be around 13.6V.
Have you tried a different set of batteries?
Any idea of the age of the original batteries? They could be sulfated and
will not accept a charge.And they need to be load-tested,their voltage
could drop under load.

 

[B Squareman]

11.9V is too low for charged Lead-acid batteries.It should be around 13.6V.
Have you tried a different set of batteries?
Any idea of the age of the original batteries? They could be sulfated and
will not accept a charge.And they need to be load-tested,their voltage
could drop under load.

The mobility's deep cycle batteries (two) are probably 5-7 years old.
I tried adding one 12.5V car battery. The motor takes 24V.
When powering the chair lifters (5-6-amp motor) consecutively for 10
seconds the voltage would drop from 12.5V to 12.4V and stay
there. The original battery will drop from 11.9V to 11.8V and stay
there until switched off. If this is a reliable battery test, the control
unit LED is still blinking. If I had a manual I'd like to know what
the blinking indicates. The circuit board used to control the wheel is
as complex as an automobile main computer.

If the circuit board wants 12 or 24V and hundreds of amps, it has got it
but still refuses to engage the wheels.

 

[Franc Zabkar]

The mobility's deep cycle batteries (two) are probably 5-7 years old.
I tried adding one 12.5V car battery. The motor takes 24V.
When powering the chair lifters (5-6-amp motor) consecutively for 10
seconds the voltage would drop from 12.5V to 12.4V and stay
there. The original battery will drop from 11.9V to 11.8V and stay
there until switched off. If this is a reliable battery test, the control
unit LED is still blinking. If I had a manual I'd like to know what
the blinking indicates. The circuit board used to control the wheel is
as complex as an automobile main computer.

It probably won't help, but could you post a photo on your web space?

If the circuit board wants 12 or 24V and hundreds of amps, it has got it
but still refuses to engage the wheels.

I'd still be blaming the batteries. Otherwise, the typical fault in
these types of devices is shorted MOSFETs in the H-bridge(s) that
drive(s) the motor(s). If your scooter has two drive wheels, then I
would expect to find two sets of four MOSFETs on a heatsink. It would
be unusual for both circuits to be faulty, however.

One other remote possibility could be that the charging socket is
open, leading the scooter's microprocessor to believe that the scooter
is being charged, in which case it will refuse to move.


- Franc Zabkar

 

[Mike]

The mobility's deep cycle batteries (two) are probably 5-7 years old.

Probably getting to the point of needing replacing ...

unit LED is still blinking. If I had a manual I'd like to know what
the blinking indicates.

All sorts of things ...

* Throttle not in neutral (i.e. the thing will drive off on its own)
Could be caused by a duff/erratic throttle pot. Or a wiring problem.

* Low battery voltage detected

* Electromechanical stop-brake won't come on/won't come off
(both have serious implications!)

* Motor fault (short/open).

* Internal fault in the H-bridge (MOSFETS) that do the driving/PWM
control.

* Chair-lift/lower sensor, if any, isn't indicating that the chair is
safely locked.

* Controller *thinks* that you are charging the unit -- it won't drive off
if you are charging!

You need the model number and manufacturer's name of the speed controller
block. They can be a PITA when they decide they don't want to play. The
blink codes aren't standard across every controller. Is it just a flashing
LED or is there a pattern of long-short flashes that are repeated?

 

[Burt Squareman]

Probably getting to the point of needing replacing ...
All sorts of things ...
* Throttle not in neutral (i.e. the thing will drive off on its own)
Could be caused by a duff/erratic throttle pot. Or a wiring problem.

* Low battery voltage detected

* Electromechanical stop-brake won't come on/won't come off
(both have serious implications!)

* Motor fault (short/open).

* Internal fault in the H-bridge (MOSFETS) that do the driving/PWM
control.

* Chair-lift/lower sensor, if any, isn't indicating that the chair is
safely locked.

* Controller *thinks* that you are charging the unit -- it won't drive off
if you are charging!

You need the model number and manufacturer's name of the speed controller
block. They can be a PITA when they decide they don't want to play. The
blink codes aren't standard across every controller. Is it just a flashing
LED or is there a pattern of long-short flashes that are repeated?

Thanks, it turned out to be loose connections. I disconnected the
motors harness and find no resistance (* Motor fault (short/open.) I
found resistance from the motors but no resistance from the control unit.
Further investigation with a special wrench I found four loose
connections. Shown on this webspace.
http://religion.p5.org.uk/s/scooter.htm

The LEDs had no blinking pattern but actually had indicated a code.
The code is the number of LED(s). The battery seems to be ok (since
it shows 9-leds) after driving it around for 30 minutes straight.

Thanks.:~)

 

[Burt Squareman]

It probably won't help, but could you post a photo on [a] web space?

Good idea, here it is.

http://religion.p5.org.uk/s/scooter.htm

I'd still be blaming the batteries. Otherwise, the typical fault in
these types of devices is shorted MOSFETs in the H-bridge(s) that
drive(s) the motor(s). If your scooter has two drive wheels, then I
would expect to find two sets of four MOSFETs on a heatsink. It would
be unusual for both circuits to be faulty, however.

I found 11 transistors on the heatsink. I got the power chair working. Thanks.