2017 ezgo 72v reversed battery terminals

[chvybeatsford]

The three that were negative volts average of 6.?? When first started. Last night they were reading -0.5?? .

Today all problems solved. My method.

Take a good 12v. (Older car battery.) Connect to the reversed battery the correct way and force some voltage into it and quicky put a charger (auto) on it. Bring it up in volts. Did that to the three. Hooked back up to cart and plugged in cart charger. Everything working as expected and charging.

We did check voltage with all hooked up and was at 63.4v.

I'll update later after 3 complete cycles of charge with out driving.

[yurtle]

So you are saying the batteries were not miswired, but just read - 6 volts for three and +12 volts nominal for the other three, so you had negative 18 volts plus positive 36 volts for a total of 18 volts? And it ran and initiated a charge when controller and charger expected 72 volts nominal? Doesn't sound right to me.

[chvybeatsford]

Originally Posted by yurtle

So you are saying the batteries were not miswired, but just read - 6 volts for three and +12 volts nominal for the other three, so you had negative 18 volts plus positive 36 volts for a total of 18 volts? And it ran and initiated a charge when controller and charger expected 72 volts nominal? Doesn't sound right to me.

Not really. Had -0.6. So batteries were completely dead and some how sucked up postive voltage through opsing battery. At first they had 6.0 but didn't notice it was a spike . So after leaving volt meter on for more than 10 secs the voltage would drop to the dead point. Sorry for confusion.

[cgtech]

Yep, all the data seemed fishy to me, that's why I stayed out. I have only seen reverse polarity on batteries installed backwards. (Those batteries don't usually make a successful recovery for long).

[yurtle]

Originally Posted by chvybeatsford

Not really. Had -0.6. So batteries were completely dead and some how sucked up postive voltage through opsing battery. At first they had 6.0 but didn't notice it was a spike . So after leaving volt meter on for more than 10 secs the voltage would drop to the dead point. Sorry for confusion.

Even if the three were absolutely zero, I find it hard to believe three 12 volt batteries totaling 36 volts powered a 72 volt charger and a 72 volt controller. Does not compute, at all.

Originally Posted by chvybeatsford

The three that were negative volts average of 6.?? When first started. Last night they were reading -0.5?? .

Today all problems solved. My method.

Take a good 12v. (Older car battery.) Connect to the reversed battery the correct way and force some voltage into it and quicky put a charger (auto) on it. Bring it up in volts. Did that to the three. Hooked back up to cart and plugged in cart charger. Everything working as expected and charging.

We did check voltage with all hooked up and was at 63.4v.

I'll update later after 3 complete cycles of charge with out driving.

No confusion on my part. You said you had three batteries that were 6 volts each. You hooked a car battery to "reverse" the polarity of the three backwards batteries and now have 63.4 volts? I suspect they would have been fine, but you messed up perfectly good batteries. You now have 10.6 volts on each 12 volt battery???

[chvybeatsford]

Originally Posted by yurtle

Even if the three were absolutely zero, I find it hard to believe three 12 volt batteries totaling 36 volts powered a 72 volt charger and a 72 volt controller. Does not compute, at all.



No confusion on my part. You said you had three batteries that were 6 volts each. You hooked a car battery to "reverse" the polarity of the three backwards batteries and now have 63.4 volts? I suspect they would have been fine, but you messed up perfectly good batteries. You now have 10.6 volts on each 12 volt battery???

I think u missed some order to things and the time it happened.
1.Cart sat 3 /4 weeks uncharged
2.Plugged in charger/ code from charger said battery pack to low to charge
3. Figured I'd charge each battery to get them up for cart charger to work. Took photo removed all wires
4. Checked voltage and 3 where low. -6.0volts or less each.(did not pay attention to volt meter enough to see if was a( -) in front number just saw the 6. My error there.
5. Plugged auto charger on on the batteries and got a error beep. Checked what that ment and was telling me my charger leads were backwards.
6. Checked again with volt meter and that's when I noticed the negative dash.
7. Check rest of batteries and 2 more were same.
8. Hit up google.. best I found was it happens. Need to drain batteries real low and charge back with cables on correct post. My charger had safety features that would not allow it to charge if the red was on a negative reading. . Red to pos post marked on battery. So since voltage was low( days past by and i drained more using a light bulb) got them to -0.60volts.I used another battery (old car batt) and jumper cables and connected them correctly for about 3mins to get them back to normal(not reverse)
9. After jumping battery I hooked up charger and brought each bad one to at min 8 volts.
10. All 3 back to a small charger I installed cables same as before that matches diagram and put back on cart charger.
24hrs later here we are. This all was over a 8/9 day deal. Just didn't post right away. And between figuring out how to solve I individually charged batteries that were not reversed.





From what I can read and understand from Google. Me allowing the cart to sit uncharged for a month with something draining them(maybe sound bar) caused my 3 batteries to reverse polarity once they were depleted. I never said it ran that way. I'm aware these three batteries could be toast. But I'm willing to see what happens. The cart charged fine all night. Just checked and at start post and end post I have 79.4 volts.. I'm going to let it sit for a few hours and check again. I don't have any thing installed besides stock run. No radio/lights installed/etc.

[yurtle]

Hope it works out. For future info, there is never a need to remove interconnecting cables to measure or charge batteries individually or two 6 volt ones in series. For carts with run/tow, I'd put them in tow.

Lotsa new info that wasn't relayed, that would have been useful to help you. I still say that leaving batteries uncharged will NOT result in batteries changing polarity. I wouldn't go a month w/o charging, but that would not cause gender changing behavior. I suspect you either misread what your meter was telling you, or you hooked the cables up wring. Either way, I hope you get things back in order. Two years or less is horrible battery life.

[yurtle]

Originally Posted by chvybeatsford

<snip>

From what I can read and understand from Google. Me allowing the cart to sit uncharged for a month with something draining them(maybe sound bar) caused my 3 batteries to reverse polarity once they were depleted. I never said it ran that way. I'm aware these three batteries could be toast. But I'm willing to see what happens. The cart charged fine all night. Just checked and at start post and end post I have 79.4 volts.. I'm going to let it sit for a few hours and check again. I don't have any thing installed besides stock run. No radio/lights installed/etc.

Is 79.4 while charging or some time after completion?

I'd definitely do several back to back charges.

[chvybeatsford]

Originally Posted by yurtle

Is 79.4 while charging or some time after completion?

I'd definitely do several back to back charges.

un-plugged. and yes will do 3 charges min before driving and testing. First drive i will only travel approx 5 miles and then charge again. Going to try and save the batteries as they are not cheap for trojan 12v. Good thing wifes cart is fine or id be dead.

[yurtle]

You don't need to drive it any before initiating another charge.