EZ Go Charger, Total Charge 3 Problem

[ajustaboards]

I have a EZ Go Charger, Total Charge 3 and when we plug the charger in to the golf cart the needle pegs out and after about 5 to 10 minutes it trips the 50 AMP thermal overload, or Breaker. Previous owner installed all new cables and the batteries are fairly new <1year. What could be the problem? I have looked up a diagram and performed the continuity checks with the multimeter. I can't figure out what is wrong. Golf cart is a 1994 Marathon, Freedom.

[JohnnieB]

Three possibilities come to mind.
Battery pack, Charger and Wiring (In alphabetical order)

Have you ever seen this cart charged with a different charger or this charger charge a different cart?
If so you can eliminate some of the three.

Since the ammeter pegs and the breaker trips, it sounds like the charger is doing what it is supposed to do, so I suspect the problem is either the battery pack or the wiring.

If the previous owner installed new cables, the first thing I would do is check the wiring.

Next I would check the voltage of each battery. They should all measure about the same. If one (or more) is significantly lower than the others, it may have a shorted cell or cells and will cause the pack to draw a higher than normal current from the charger.

If that didn't reveal the problem, I would put a Voltmeter across the battery pack (B+ to B-) and note the voltage. Then plug in the charger and note the voltage it jumps to before the breaker trips.
I believe it is rare to see a charger putting out an abnormally high voltage, but it is possible.

There is another possibility. If the battery pack is deeply discharged (<36v) it will draw a very high current initially.
Of course, if it is discharged to the point of pegging the ammeter and tripping the breaker, the batteries may not be salvageable. That kind of abuse can kill brand new batteries.

Hope this helps.

Added:
Another possibility is the big capacitor connected directly to the transformer.
I'm not up to speed on how ferroresonance works, but that capacitor in conjunction with the third winding on the transformer, regulates the charge's output.