Help Powerwise II charges but cuts off after about 30 mins

[Thomas41]

I have a 36vlt Powerwise II Charger that charges 44 vlts when first plugged in, but will suddenly cut off after about 30 mins resulting in the batteries not being charged. I have replaced the old batteries with new trojan 6 volt batteries, but the problem still exist. The PowerWise charger was recently (last year) repaired in which the capacitor was bad. Any ideads will be greatly appericated. Thanks

[JohnnieB]

The output of a PW-II is connected to the battery pack, so the output voltage of a PW-II is going to be the same as the voltage of the battery pack it is connected to. The pack voltage of a 36V pack of Trojan batteries will be 38.3V or less after use, so I'm not sure how it is possible to get a 44V reading when first plugged in, unless there are some bad connections between the charger and battery pack.

[Thomas41]

Originally Posted by JohnnieB

The output of a PW-II is connected to the battery pack, so the output voltage of a PW-II is going to be the same as the voltage of the battery pack it is connected to. The pack voltage of a 36V pack of Trojan batteries will be 38.3V or less after use, so I'm not sure how it is possible to get a 44V reading when first plugged in, unless there are some bad connections between the charger and battery pack.

Thank you for the response. I took the charger in for testing. The tech stated that when plugged in, it goes to 44 volts before going down to charging at 38 volts. He stated the problem is most likely the electronic timer. Since they don't repair chargers I have a choice of buying a new charger or repairing it myself. Unfortunately when I look at the boards none seem to match the one I have. Do you have a recommendation on what will replace EZGO 603194 Electronic Charge Controller with Relay Board?

[JohnnieB]

The control/relay board is a semi-smart on/off switch, and has nothing to do with the battery charging process other than turning the connecting or disconnecting AC power to the transformer primary winding.

The control board senses the battery pack voltage and if it is over about 30V and under about 45V, it energizes the relay applying AC power to the transformer.

The control board then monitors the battery pack's On-Charge voltage (aka chargers output voltage) and when it rises to 45V +/- 1V, it de-energizes the relay, removing AC power to the transformer, thereby terminating the charge cycle.

There is also a safety timer on the control board that de-energizes the relay if the On-Charge voltage fails to reach 45V +/-1V within about 16hrs.

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The battery charging portion of the charger consists of the ferroresonant transformer center tapped secondary, matching booster capacitor and diodes. There may also be ammeters and fuses in the output circuit.

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The output voltage going to 44V and then down to 38, indicates a bad connection someplace between the transformers secondary and the individual batteries.

Here's a schematic , a service manual and a troubleshooting guide for a PW-II, which is a more or less a relabeled Lester-II

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I'd disassemble and clean the cart's charge circuit as well as the PW-II's output circuit. Bright metal to bright metal on all connections and contacts.

[Thomas41]

Thanks for you help....as much as I feel like a complete dumb *** now I figured out the problem. I tested the charger, before going to get another charger showing the same result. I tested the batteries, which all test as well. It was at the point of literally pulling my hair out when I remembered about having to reset the digital voltmeters. Well once completed, it showed a fill charge. On the bright side I did find a faulty wiring connector.