Sat. Charging Fine - Sun. Charger Won't Charge

[konakid]

I have an older cart with an older Power Wise charger. You guys have been helping me with a boatload of little issues - and each time I think I have found the last one - only to have another gremlin pop up.

Hopefully, they are all related - and hopefully maybe related to this latest problem. I've been cleaning terminals, checking voltages, and replacing switches. So far the pedal microswitch, solenoid, and that diode thingy connected to the solenoid (discharge something or other) has been replaced.

After each fix I think I finally solved the main problem because it works for days or weeks - only to mess up again. That is, it sometimes acts like there is very little voltage (or none), even after a full charge. And then after flipping switches back and forth, it runs good as new again.

But now - the charger is dead when I plug it in. I checked the charger connections, the diodes, etc. and they are fine. And when I jump the relay, it works.

I am hoping that whatever the cart is not doing to let the charger know it is there, may be related to my elusive main problem.

Any suggestions on where to go from here??? The pack voltage is 38v and dropping since I can't charge it. Each battery is 6v or 6.1v. I've checked that the little clip inside the plug has continuity to the terminal inside the charger - as well as the two main plugs.. And the cart is running at the moment.

Before I was able to charge up to well over 36v and it would shut off. I'm not sure what to look for, or how everything is supposed to work here. It believe it is a TXT - using an NCX controller.

[cgtech]

The small "extra red wire" in the charger cord is prone to fail. Dont know why, but it does.. Seen it many times. The "whole charger cord" is stupid-expensive. Yep, been there, done that. Eliminate the red wire if need be. That is one of the first things i check. Its not a great thing to do (its the voltage sense wire), but the price to replace is stupid-expensive. They did it for a reason (to monitor voltage at the cart) . Not sure why that wire fails so often.. you can bypass it. but you really need a new DC cord from the charger to the cart. Its one of those things is hard to explain to the typical cart user. Its purpose is to give the charger a accurate read of the voltage of the pack while charging it. (the reading at the "charger end" of the wire is different than the "battery pack" end of the wire). Its a good idea "in theory", but not perfect in the real world. Just like the clubcar "obc" "count in-count out" is great in theory. In the real world, minor variations do exist.

[konakid]

Thanks "cgtech,"

Two questions please:
- I am not sure what you mean by "new DC cord from the charger to the cart." Do you mean the cord with the plug?
- I looked up some of the Power Wise diagnostic online videos - and according to them, the problem is the board. Read below and tell me what you think?

I can bypass the relay and the cart starts charging, the amp meter starts out where it is supposed to be, and it is dropping slowly as it always did. Without bypassing the relay, it is totally dead.

I had a problem with this cart and charger when I first bought it (very used) in that that charger would not turn off. So, after asking around here I opened it up and found the relay was bypassed. I stuck it back onto the board as it should be, and it worked perfect for about 4-5 months - until this latest failure. I was never sure why it was bypassed in the first place.

But now with the relay bypassed, it is operating like it did when I first got it. So, I was going to order a new board, because that is what the diagnostics indicated.

Do you still think it might be what you mentioned???

[kgsc]

If I remember correctly the red wire coming into the charger is touching the black wire at the socket end with it plugged into the cart. Could he check voltage between the red and white wire coming in to determine if that wire is bad? AC cord unplugged of course. And if there is no voltage could he connect the red to the black in the charger box itself to see if the relay kicks in? If the answer is yes and it is just a bad wire I would run another one along side the current cord and just tape it to it. Not pretty but would work.

[JohnnieB]

The charger doesn't not have to be plugged into AC power to check if the battery sense circuit is working. Just listen for the relay click.

It is the cart's battery pack that energizes the relay initially. Once the relay clicks, AC power is applied to the transformer and the charger starts producing a DC output voltage, which then holds the relay closed until the pack voltage rises to about 45V and the control board opens the relay's coil circuit, causing the relay to de-energize and remove AC power from the transformer.

Instead of running a separate wire outside the DC output cable, you can re-route the battery sense wire from the control board to the transformer center-tap inside the charger. (This is charger model specific - have to look at schematic to determine where to connect in other models)

[kgsc]

Yeah the outside wire was just a thought but was hoping someone would chime in hooking it up inside the charger. I think it would be the black wire in the dc harness ??

[konakid]

I have checked continuity from the little clip inside the plug, through the red wire to the inside of the charger (to the little inline disconnect) - and it is good. But not from that last foot to the board.

With the relay bypassed I charged for about 10 hours. The amp meter readings ended up at about 9, and the pack voltage after about an hour after uplugging it was 38v.

Are those readings normal?

I thought that the board was "smart" in that it sensed the voltage rise while charging and adjusted the charging profile accordingly, until cut off. Is this not the case?

In any event, I ordered a new board, since the diagnostic videos said that if all the continuities checked out, the diodes were good, capacitor was good, and transformer was good - it had to be the board - especially if it charged with the relay bypassed.

They also said that bypassing the relay would eventually burn out the board.

Any more useful feedback? I really appreciate the help. I'll report back after I get the new board in.

[kgsc]

You said you checked continuity but did you check for voltage ? Should be 36+ with the red as the ground and white as the +

[konakid]

Originally Posted by kgsc

You said you checked continuity but did you check for voltage ? Should be 36+ with the red as the ground and white as the +

Just went and took that reading. With the DC plug in the cart and wall AC unplugged - the red wire disconnect inside the charger to the white wire terminal inside the charger yielded almost 38v.

[JohnnieB]

Originally Posted by konakid

1. I have checked continuity from the little clip inside the plug, through the red wire to the inside of the charger (to the little inline disconnect) - and it is good. But not from that last foot to the board.


2. With the relay bypassed I charged for about 10 hours. The amp meter readings ended up at about 9, and the pack voltage after about an hour after uplugging it was 38v.

Are those readings normal?

3. I thought that the board was "smart" in that it sensed the voltage rise while charging and adjusted the charging profile accordingly, until cut off. Is this not the case?

4. In any event, I ordered a new board, since the diagnostic videos said that if all the continuities checked out, the diodes were good, capacitor was good, and transformer was good - it had to be the board - especially if it charged with the relay bypassed.

5. They also said that bypassing the relay would eventually burn out the board.

Any more useful feedback? I really appreciate the help. I'll report back after I get the new board in.

1. You should have continuity from the "little clip inside the plug" all the way to where the battery sense wire attaches to the control board. If you don't, that may be the reason the charger is not turning on and off automatically.

2. The 9 amp reading after 10 hours of charging might be a little high and the 38V reading one hour after the charger was disconnected may be a bit low, so those readings might not be "normal".

After 10 hours of charging, the ammeter ought to be closer to 5A and the On-Charge pack voltage ought to be about 45V or higher.

After the pack has rested (neither charged nor discharged) 12 hours, the pack voltage ought to be about 38.2V (Trojan batteries and clones) and after only an hour of rest, the pack voltage ought to be higher than 38V.

3. No, the control board has nothing to do with the charge profile. The charge profile is designed into the Ferroresonant Transformer and Capacitor pairing.

At best, the control board is a semi-smart On/Off switch.
A. It applies AC power to the transformer when it is connected to a battery pack whose voltage is high enough to energize a 36VDC relay.
B. It disconnect AC power from the transformer when the On-Charge pack voltage climbs to about 45V.
C. If the On-Charge pack voltage does not climb to the cutoff voltage (~45V) within the allowed time limit (Typically about 16 hours), it disconnect the AC power from the transformer.

4. Some of the on-line troubleshooting videos jump to conclusions rather than proving an item is bad.

To check the control board, measure the voltage between the small red and black wires (battery sense wires) were they are soldered to the board. When charger output plug is plugged into cart, the voltage between the Red and Black wire should be the same as the voltage between the battery pack's main positive and main negative terminals.

If it isn't, fix the wires and connections.
If it is, and the pack voltage is above about 28V, the relay should click. If it doesn't, then it is a reasonable conclusion to consider the board to be bad.