Yamaha 48v Golf cart charger says ABNORMAL CYCLE

[ichudov]

I recently acquired an electric Yamaha golf cart.

As the batteries were bad (checked with voltmeter, charged with a power supply, and attempted to run golf cart), I purchased six brand new batteries yesterday.

Installed them and double checked their proper wiring and polarity. Exactly as the sticker said.

We ran the cart for a few minutes (like 15 minutes) and put it on charge.

The charger started and displayed "INCOMPLETE, CHARGING", which I thought was normal.

However, after a while, it displays the dreaded ABNORMAL CYCLE message.

Upon hearing about it, I instructed my kids to disconnect it.

Having come home in a few hours afterwards, I measure voltages on EACH cell, and the values were between 8.34 and 8.36 volts per battery.

What gives, and what can possibly be wrong?

Thanks

[teecro]

As I don't know a thing about YAMAHA carts I'll approach it in a generalized fashion... Those batteries are not fully charged, they are roughly 80 % according to your readings. Turn the key switch to OFF, if the cart has a RUN/TOW switch switch it to TOW, disconnect your main pack NEGATIVE cable and wait an hour, connect your main pack (-) and plug in the charger to the cart and then the charger to the electrical outlet. Hopefully this resets the cart and prompts the charger to charge the batteries. Allow the charger to do its thing without any interference from you at all for at least 16 hours.

[ichudov]

Originally Posted by teecro

As I don't know a thing about YAMAHA carts I'll approach it in a generalized fashion... Those batteries are not fully charged, they are roughly 80 % according to your readings. Turn the key switch to OFF, if the cart has a RUN/TOW switch switch it to TOW, disconnect your main pack NEGATIVE cable and wait an hour, connect your main pack (-) and plug in the charger to the cart and then the charger to the electrical outlet. Hopefully this resets the cart and prompts the charger to charge the batteries. Allow the charger to do its thing without any interference from you at all for at least 16 hours.

Thank you teecro. I read your message and decided to do exactly as you said.

1) I measured the voltage BEFORE I plugged in the charger: 50.0 volts.

2) Then I made sure the key was turned OFF, and the selector RUN/TOW was set to TOW.

3) Then I plugged in the charger. After it initialized, and reported that it started charging, the voltage across batteries was the same, 50.0 volts. Just in case, I kept it on, and returned 30 minutes later: still the same 50.0 volts.

What this means is that the charger is NOT charging.

Any idea what could be wrong?

[teecro]

Well it does indeed sound like the charger is not charging and if the charger tells you that it sees the batteries and yet still does not charge then you got a charger problem... Again I don't know enough about YAMAHA carts and their chargers to be of much help. You might try bringing the charger to a YAMAHA Golf Cart Dealer they might be willing to plug it into another cart to see if it has the same issue there too. They may also be willing to let you borrow a charger so that you can double check your cart at home...

[ichudov]

OK, I think that I figured it out. I opened up the charger. It was obvious right away.

One of the wires coming out of the relay, with a spade terminal, melted off that terminal.

I have pictures and some more details on this web page (remove spaces from below address):

www machinerymoverschicago com /blog/Yamaha-48v-Golf-Cart-Battery-Charger/

It is charging now, the charging voltage is 52.5 volts, a lot more than the non-charging voltage of 50 volts.

I will keep an eye on it.

I bought a replacement relay also, just in case, as this one suffered heat damage.

[Nanatech3]

Mine is doing the same thing. I have the same exact charger.. Thanks for the tech tip as to where to look.

[cgtech]

Originally Posted by Nanatech3

Mine is doing the same thing. I have the same exact charger.. Thanks for the tech tip as to where to look.

Also, if yours has the fuse window at the bottom of front panel, closely inspect those wires too.