EZ Go Charger Problem

[jwdixon]

I just bought an older Marathon, not sure of the year. Probably check on that in another thread. My problem is the person I purchased it from gave me one of the older Lester charger and a newer powerwise charger code 28115 Go4.

He said the old charger was really loud so he had purchased the newer charger and tried to retrofit the plug from the Lester to the powerwise. He said he wasn't ever able to get it to work. Thought he had it wired wrong. After going through the charger it has definitely blown the control board and the 50 amp fuse.

Before I replace these to use with the Marathon will it even work with it? Can I wire the old plug to the charger in a way that will get it to charge my cart?

On a separate note I wired the old charger back to the charging plug. I then plugged into a/c and metered the output at the plug and it is metering around 2.6 volts. Should this be 36 volts? Or does that only happen when plugged into the cart?

Thanks for any help.
John

[rabbitreborn]

First, yes, the powerwise can be wired to function with the older cart.

Second, yes, the charger will only output when connected to the cart at 36 volts (actually closer to 42 volts at it's peak)

[jwdixon]

Thanks rabbit. I am wondering if anyone knows what the red wire coming off the control board does that goes into the plug. If I retrofit my older plug which has just two wires (white + and black -) what does the red wire do? Do I just cap it off? Is this what senses voltage level on the cart?

thanks again

[JohnnieB]

Originally Posted by jwdixon

Thanks rabbit. I am wondering if anyone knows what the red wire coming off the control board does that goes into the plug. If I retrofit my older plug which has just two wires (white + and black -) what does the red wire do? Do I just cap it off? Is this what senses voltage level on the cart?

thanks again

The wire senses battery voltage and if the control board sees something above about 28-30 volts it will turn on the charger. The charger will not turn on without it.

Go to the bottom STICKY at the top of the Electric EZGO forum and download the service manual. Charger schematic is Figure-8 Page K-6 (Page 142 of 228 in Adobe Reader)

It appears the the third (smaller) wire in the charger output cable connects to the Negative terminal of the battery pack via the Aux Contact in the new style charger receptacle. The only problem I see in connecting it directly to the "-" connector in the older style plug is that the charger would not turn off if the plug was disconnected. (It would still turn of when the charge cycle timed out though)

Before it comes up. The third wire in the cable from the charger turns on the charger. The third wire in the receptacle mounted on the cart, disables the cart while charger cable is plugged in via the reed switch. Separate circuits with separate functions. Third wire in cable attached to charger is looking for B- while third wire in receptacle mounted in cart is looking for B+.

[jwdixon]

Johnnie B thank you for your detailed explanation. I think I follow everything you have said.

If I may ask one more question. Does anyone have experience with the Protech chargers that ScottyB sells. The reason I ask is I know my charger has a blown input board, blown fuse and the heat sink with diodes are bad too. I'm guessing I'll have another $135 bucks in it and still have a charger doing something its not designed for. Wondering if just going with the other charger would be a better long run investment and then either repairing the powerwise back to its original form selling it for parts.

Any thoughts?

[rabbitreborn]

Originally Posted by JohnnieB

The wire senses battery voltage and if the control board sees something above about 28-30 volts it will turn on the charger. The charger will not turn on without it.

Go to the bottom STICKY at the top of the Electric EZGO forum and download the service manual. Charger schematic is Figure-8 Page K-6 (Page 142 of 228 in Adobe Reader)

It appears the the third (smaller) wire in the charger output cable connects to the Negative terminal of the battery pack via the Aux Contact in the new style charger receptacle. The only problem I see in connecting it directly to the "-" connector in the older style plug is that the charger would not turn off if the plug was disconnected. (It would still turn of when the charge cycle timed out though)

Before it comes up. The third wire in the cable from the charger turns on the charger. The third wire in the receptacle mounted on the cart, disables the cart while charger cable is plugged in via the reed switch. Separate circuits with separate functions. Third wire in cable attached to charger is looking for B- while third wire in receptacle mounted in cart is looking for B+.

Perfect description, thank you for explaining all that to our member. The only thing I saw wrong is your information regarding the charger not shutting off. Once the charger handle is disconnected from the cart, the charger WILL turn off. I have done this on multiple chargers and never have an issue doing so.

[JohnnieB]

Originally Posted by rabbitreborn

Perfect description, thank you for explaining all that to our member. The only thing I saw wrong is your information regarding the charger not shutting off. Once the charger handle is disconnected from the cart, the charger WILL turn off. I have done this on multiple chargers and never have an issue doing so.

Thank you for the kind words. Many moons ago, I taught troubleshooting techniques to some of the finest lads and lasses this country has to offer and my West Virginia persona slips occasionally, so stuff like that slips out from time to time.

On the charger schematic I see the box outline of the control board getting B+ straight from diode board and B- from the Aux Contact in the Charger Receptacle on the cart.
With third wire hardwired to B- contact in the charger cable, it would act like a self-holding relay, with the control board seeing the charger output voltage as the battery voltage.
However, the fact that it does turn off when charging cable is unplugged, means I've overlooked a third function of the control board. It shuts off the charger when the sensed voltage raises to a predetermined point.
The charger's output voltage would go to max the instant the cable was unplugged, causing the control board to think the battery was fully charged and shut down the charger.

Please correct me if I am wrong: (I don't have an actual schematic of the control board itself, so I'm more or less guessing. )
*The control board has to sense a minimum voltage before it will energize main relay and apply AC to transformer primary.
*The lower the sensed voltage, the more current is allowed to flow to the battery initially.
*As the sensed voltage increases, the current that is allowed to flow decreases. (This is accomplished by the third winding of the transformer and the capacitor in parallel with it - Ferroresonance)
*When the sensed voltage reaches a level that indicates a full charge, the control board de-energizes the main relay.
*If the sensed voltage do not raise to the full charge level within a specified time period, the control board de-energizes the main relay. (Safety feature)

[rabbitreborn]

Originally Posted by JohnnieB

Please correct me if I am wrong: (I don't have an actual schematic of the control board itself, so I'm more or less guessing. )
*The control board has to sense a minimum voltage before it will energize main relay and apply AC to transformer primary.
*The lower the sensed voltage, the more current is allowed to flow to the battery initially.
*As the sensed voltage increases, the current that is allowed to flow decreases. (This is accomplished by the third winding of the transformer and the capacitor in parallel with it - Ferroresonance)
*When the sensed voltage reaches a level that indicates a full charge, the control board de-energizes the main relay.
*If the sensed voltage do not raise to the full charge level within a specified time period, the control board de-energizes the main relay. (Safety feature)

You've got it dead on.... Every now and then E-Z-GO's engineers actually do get something right... and since the powerwise charger was completely built in house, they get total credit for thinking things through this time.