mobility scooter power issues

Thread Starter

B7100

Joined Jun 14, 2015
10
I HAVE A PRIDE victory scooter. It doesnt seem to have the power it used to have. I have installed new batteries and throttle pot. I put it up against a wall and hooked the motor direct to the batteries and it smoked the tires. I sent the controller to a person who rebuilds them and he said there was nothing wrong with it. I use the scooter on hills and through high grass and over some pretty rough terrain. In using it it seems as though the voltmeter on the dash dips way down under the least bit of load put on it. The breaker trips under the slightest load. On level hard surface it will run several hrs. I have 2 new 50 amp batteries installed.
 

#12

Joined Nov 30, 2010
18,216
Hmmm...It has such good connections that it trips breakers and it has such poor connections that the voltmeter dips. That sounds like 2 problems. The first one makes me suspect mechanical wear in the drive train which loads the battery unnecessarily. The second one seems like a dirty connection. The ultimate cure is to hire a top notch scooter technician, but they are nearly impossible to find, even in Factory Service. :(
 

Alec_t

Joined Sep 17, 2013
11,803
I'd start by checking/cleaning/re-making any wiring connections to the scooter chassis and battery terminals.
 

Thread Starter

B7100

Joined Jun 14, 2015
10
I'd start by checking/cleaning/re-making any wiring connections to the scooter chassis and battery terminals.
Thanks for the replys. I'm not good at diagnostics. How would you go about finding a bad connection and what do you use to clean it up when you find it? I have taken it to a repair shop. They were absolutely worthless. There cure was to sell me a new scooter.
 

Thread Starter

B7100

Joined Jun 14, 2015
10
How do you check/clean connections? I'm not good at diagnostics. Like i said i put it up against a wall and hooked it direct to the battery and it would smoke the tires. I don't think it is mechanical. I took it to a repair shop and they were about worthless. Their cure was to sell me a new scooter. I have two of these and they are both doing the same thing. I have swapped parts between them and it doesn't help. They had power when they were new.
 

Thread Starter

B7100

Joined Jun 14, 2015
10
How do you check/clean connections? I'm not good at diagnostics. Like i said i put it up against a wall and hooked it direct to the battery and it would smoke the tires. I don't think it is mechanical. I took it to a repair shop and they were about worthless. Their cure was to sell me a new scooter. I have two of these and they are both doing the same thing. I have swapped parts between them and it doesn't help. They had power when they were new.
I ran the scooter a little and felt the connections. The wires to the batteries felt a little warm. The lugs on the connectors don't look corroded however where they are crimped on the wires they appear burnt. The ground wire to the battery has the insulation melted. Replace wiring harness? New connectors? Sorry about the double post. I am having a little trouble figuring out how to post replies.
 

#12

Joined Nov 30, 2010
18,216
In my world, melted insulation is always a sign of a bad connection. Cures might include: replacing that cable, replacing the end on that cable, cleaning the cable end and soldering the connector on to it (not an amateur sort of job).
 

Thread Starter

B7100

Joined Jun 14, 2015
10
In my world, melted insulation is always a sign of a bad connection. Cures might include: replacing that cable, replacing the end on that cable, cleaning the cable end and soldering the connector on to it (not an amateur sort of job).
I replaced all the connectors. It seems to have improved the performace some
 
Maybe a little "counter intuative", but you can look a small voltages "ACROSS" connections with current flowing through the wires.

That simple battery cable with a battery connector at one end and say a ring terminal at the other is full of contact resistances.
(clamp to battery) (crimp to wire) (wire) (wire to crimp) (lug to whatever). You can generally measure the voltage ACROSS all of that stuff. The drop will be in millivolts.

You can also measure the voltage across the motor at full throttle and full load. Now you may have rig something to do that.

Look for signs of heat and corrosion. The bike may have a fuse or "fuseable link".

If the voltage to the motor at full throttle is bad, then we have issues. I am assuming a PWM controlled motor and not a three phase motor.

Motor brushes, fuse contact resistances, crimps

Do you have an electrical schematic you can post?
 

Thread Starter

B7100

Joined Jun 14, 2015
10
Maybe a little "counter intuative", but you can look a small voltages "ACROSS" connections with current flowing through the wires.

That simple battery cable with a battery connector at one end and say a ring terminal at the other is full of contact resistances.
(clamp to battery) (crimp to wire) (wire) (wire to crimp) (lug to whatever). You can generally measure the voltage ACROSS all of that stuff. The drop will be in millivolts.

You can also measure the voltage across the motor at full throttle and full load. Now you may have rig something to do that.

Look for signs of heat and corrosion. The bike may have a fuse or "fuseable link".

If the voltage to the motor at full throttle is bad, then we have issues. I am assuming a PWM controlled motor and not a three phase motor.

Motor brushes, fuse contact resistances, crimps

Do you have an electrical schematic you can post?
I checked the voltage at the motor terminals. I got 24 volts at full throttle. I checked the motor terminals with an ohmeter. It pegged the ohmmeter in all settings. I took one brush out and it didn't look worn or damaged. It was about 7/8"long. Is there another way to test the motor? I took it to an automotive alternator repair shop and they said it was fine. Are these motors repairable or just replace them? Is there a source other than pride($) to get these. What is the type/mount/size i need to look for?
 

ramancini8

Joined Jul 18, 2012
473
Some times you get what you buy---seems like your scooter doesn't have the inherent capability to do what you want. When you have full 24 volts across the motor that is as fast as it goes unless there is a mechanical problem like no grease in the gear box, etc.
 
Make sure that 24 V is measured under the loaded conditions. If you have to attach the voltmeter and take a ride, do so.

Otherwise, I think, I might be looking for something mechanical. e.g. broken shear pin, bad bearing, dirty bearing, sticking brake etc
 

Thread Starter

B7100

Joined Jun 14, 2015
10
Make sure that 24 V is measured under the loaded conditions. If you have to attach the voltmeter and take a ride, do so.

Otherwise, I think, I might be looking for something mechanical. e.g. broken shear pin, bad bearing, dirty bearing, sticking brake etc
I think it is possible that I am expecting more than the scooter is capable of. I weigh 250 and going up a hill on a dirt surface does take considerable power. On a level paved surface with good batteries they don't do too bad. That is probably all they are designed to do. For my purpose I probably need to go up a notch. That means a bigger scooter and a bigger vehicle to haul it around in. I guess its make do with what I have, upgrade what I have (big$) or get a bigger scooter (big$). It has helped to replace some of the burnt connectors.
 
Hi i agree with what you say but now and again i get an answer that i can work with so i'll repost a new post and describe what i'm trying to say in different words with pics as well now that i am learning things , sadly i need some very simple answers to some questions for me to understand
 
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