Troubleshooting Non-DCS Controller (Heat)

gonesouth

I have a mid-90's Ez-Go electric with non-DCS controls. It is getting hot under the controller cover (both solenoid and controller box) and as well the battery charge runs down quickly.

Last year I rebuilt the FxR switch and it ran well, with battery life of about 3 miles, or 5km. This fall I cleaned all wires and battery posts and replaced a couple of wires.

Since then it has been slowing down, and yesterday it only ran about 1 mile before being substantially discharged (had to limp home) and I found the heating issue.

How do I see if it is the solenoid or the controller box? Further, are there user-serviceable parts inside the controller?

Thanks

Jim

BGW

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scottyb

Under the environmental cover you'll find the electronic speed control and main solenoid switch. Neither of these items require maintenance or service. They can be upgraded to allow the motor to access more amperage for improved torque.
It sounds to me like you may be having a battery issue. 1-3 miles is a pretty short runtime.
If you are pulling high amperage loads with the stock controller it will get too hot and going to thermal cut back or limp mode depending on which model you have. If the cart runs okay after it cools off then this may be what's happening and an upgrade is in your future. If the cart continues to run slower poorly after it cools you may be losing contact in your forward and reverse switch. I hope this helps

gonesouth

Thanks, Scottyb, that's helpful.

But to be sure I understand you right, are you saying that it sounds like the batteries are not charging well, and so voltage is lower than it should be, and so the controller is passing more amps than normal? I can see that this would lead to overheating, just didn't know that the controller would pass more current when the voltage is low.

Is there somewhere I can read a description of how the controller works? For example, my understanding is that the accelerator pedal is a resistance bridge, and varies the voltage signal going into the black box. So how does the box then react to slow down the motor? If it was digital I know it modifies the wave patterns, but this one isn't digital, is it?

I always thought non-dcs meant non digital control system, but I am probably well off course.

Thanks

Jim

scottyb

For any given task, volts x amps = power.
Ask the motor to pull the cart up hill with 38v supplied and it will draw less amperage to do so than if you supply only 24v. The more amperage you use the hotter everything gets.

cgtech

1-3 mile range is horrible, one or more batteries must be bad. Checking the batts is top of the list. Put a volt meter on the charge plug sockets and monitor voltage while driving (or better yet, while someone else drives). As soon as voltage drops below 31.5v while at anything less than full acceleration, the batterys are considered discharged. This could indicate they are all discharged, or a few are seriously limiting the better ones. Stop and check individual voltages of the batteries, the lowest ones are to be suspect first, any below 5.5v while at rest are totally junk. A automotive battery load tester is also a great tool for this test without driving (cheap at harbor freight). Stay close to home so you dont have to walk.

gonesouth

Thank you guys for the cheap education!

After your posts, I put a 12V charger on one pair (in series) and charged them overnight. They are now up to 13V, which is higher than I remember ever seeing the batteries, so I am now thinking I have a charger issue..........to diagnose this I need to know:

What should the charger voltage be? trojan says for wet batteries that 44.4 v is right, and 46.5 for equalization for a 36v sysytem.

Could corrosion on the charger connector male or the cart female connector be causing this? Well, duh! I guess it could.

I'm going to go out and connect up my cart charger and then measure voltage across B+ to B- and see what I get. I guess the batteries will drag that down, so I'd better try the connector first.

Have any of you ever cleaned a connector, or should I just go buy new ones if these are corroded?

scottyb

The female charge receptacle contacts are called radsoks. You can purchase them - they are a wear item.

gonesouth

Thanks, ScottyB

Awesome that you are so willing to help people.

I am now checking the charge to see at what point the charger stops charging. Will post back.

Jim

gonesouth

So, I tried charging with my charger and my charger is shutting off at 37.4V across the batteries.

So, next step is to try my friend's newer 36v Powerwise charger which works great on his cart. Answer is, it started at nearly 20 amps by the needle gauge, but shut off at 37.4 v.

So, clearly my charger is working fine. So does this mean that I'm losing 6.6 v in the wiring across the system?

Or am I not understanding how the system works. My understanding is that the charger senses the charging current and when it drops below a given point it switches to an equalizing charge for some specified time, then shuts off. If that is so, could the corrosion or a partly corroded cable or connector piece be slowing the current to the point it gets a FALSE 'all charged' signal???

I am leaning to that explanation partly because both chargers stopped with the same charge on the battery set, and partly because when I reconnected each charger after it had already stopped, it started again and the batteries began 'burping' fairly actively, indicating that it was giving it equalizing voltage.

Am I making any sense here?

scottyb

Curious to know what your friends charger brings his cart pack up to before shutting off.