HELP! I'm trying to resurrect an old EZGO Golf Cart for our club. The charger "may" be useable, we are going to need to replace the 6 batteries as they have been frozen, probably more than once, and some of the cables are corroded away completely. Much of the repair is straight forward and the mechanical aspect of the cart is sound despite neglect.

The battery connector on the charger, a "Total Charger" from EZGO, was destroyed but I can slap together a combination from an old dryer plug and receptacle which will certainly handle the current. Here is the rub, the polarity for the DC or "Battery" connector. It appears from what remains of the connector as though it was wired with the Black lead going to the Negative and the White lead to Positive.

While I realize AC and DC conventions are different, I'm questioning the polarity and don't want to reverse it as it would probably damage the charger if it hasn't already.

I contacted EZGO and they sent a "Wiring Diagram", not a schematic, but it does not show the connector. The Diagram just shows the two lead charger cable going off the diagram into the great unknown. It seems actual Schematics are proprietary to their authorized dealers.

If someone has an older EZGO with one of the "Total Charger" units, and could look at the connector, please contact me. Maybe someone even works on the EZGO carts and has first hand experience. Thanks

scimitar1,
Lead acid chargers are almost always constant-voltage chargers, and when you plug them in you will find that they put out a steady voltage a little higher than the batteries to be charged.

If you'll just disconnect the charger from the batteries, then plug it in, (assuming that this is not some really complicated, computer controlled charger) you'll find that it puts out somewhere between 14 and 18vdc unloaded. Just read the polarity with your meter, then connect + of the battery to + of the charger, and - to -.

Joe myers

Another hint. Always have the charger off before you plug the batteries in or unplug them. This way your make-shift battery connectors (dryer plug) will last. DC connectors have huge copper contact area compared to their AC counterparts. That's why a switch is rated for 10 Amps AC but only 3 Amps DC.

This charger, although old, is a bit more complex and requires a voltage from the battery (36 volt, or so, if depleted) be connected to it before the sensing circuit will close a relay on the internal PC board to allow the AC into the transformer primary.

That is why I need to confirm that the charger output leads are White for Positive and Black for Negative before I go attaching them to an actual bank of 3 large 12 volt batteries and burn up the charger if the polarity is reversed.

I had hoped that someone either had an old EZGO cart with the "Total Charger" unit or even had a schematic. I guess I'll keep hoping.

Thanks

Oh Yeah been there done that on 2 old EZGO's we bought at a car auction. We did find one source online for the manual and parts . I'll warn you now they get$58 bucks for the thing but it will help you a great deal in putting the Old EZGO back in shape.
The link is below. They handle parts for most Golf and Utility carts so just follow the EXGO thread under manufacturer.
Good Luck with your project.
http://www.powellscartsandparts.com/

Scimitar1
I just checked two EZGO's here at work and both their chargers are wired green / red / black. I think your best course is to take r1morris advise and purchase the manuals.
John

John,
Was one of the wires (probably the red) much thinner and used for the feed to tell the charger a battery is connected? More current Chargers use three wires to the battery connector with the small wire used only as a sensor lead and not carrying any of the charge current. This old "Total Charger" uses only two leads but has a tap inside the charger going to the PC board. I take it you don't have a schematic (not just a wiring diagram) either??

Mark

Scimitar1,
The green is a ground with the red wire being positive and the black negative. All the same guage. If you want I can probably take it apart and take a picture. I haven't suggested this before because the charger is bolted to the EZGO under the hood and Maintenance is running all over the plant with them!

Let me know,
John

PS No I don't have a wiring diagram.

I've never seen a remote control golf cart before. What scale is it?

John,

Built in chargers may have been installed with heavier wire. Any chance the Maint. dept might have a manual with a schematic that could be scanned and sent?? Really appreciate all your help.

Mark

In the thity or so years that I have been dabbling in electronics, Black is always negative in DC and positive in AC.

I would be willing to bet that the black lead is - and the white is +.

Yup Jim,
Works just fine IF an electrician wired it. I've seen too often someone who doesn't know what they are doing just puts a cord on. 50 - 50 chance. My chargers at work have red and black leads.

Just looked at the information that came with our EZGO. There is absolutely NO schematics for the power supply!!!

OK - Brain is finally working. Put a 12v car tail light bulb (enables you to draw about an amp of current) in series with the white lead and hook it to the positive on the battery. Hook the black to the negative. We are going with Jim's labeling of polarity. If the charger is hooked up wrong the current limiting resistance of the bulb should prevent it from blowing out the charger. If the bulb glows measure the voltage polarity at the charger and determine if it is correct. It probably will only glow with the charger hooked up in one direction.
Good luck,
John

I'll give the load/current limiter a try. As it is a 36volt system, I may use a larger load to protect the charger.


THANKS to all for your suggestions.

Mark