1995 Medalist DCS Reverse Battery Polarity

[JCMoney]

Ok, so after digging through several battery forums, DIY golf cart resources online and some physics blog it appears as though I've charged my 6 V Trojan battery into the deep cycle battery form of a UFO, Abominable Snowman or 2 headed snake...

My battery has reversed polarity.

I didn't charge it backwards. The multimeter isn't hooked up wrong, etc. The battery's polarity is reversed. Plain and simple. Here's how I got to this point:

My in-laws had an old 1995 medalist DCS EZGO sitting in their garage for the last 10 years without working and before they were going to get rid of it, I wanted to take a stab at it and see if I could get the old dog up and running.

All 6 batteries were at under 1 volt per the multimeter so I had little hope for them, but thought it was worth a shot. Nothing to lose, right?

After watching a few youtube videos posted by golf cart repair shops about restoring dead golf cart batteries, I removed the batteries from the cart, cleaned out each batteries with baking soda and distilled water to get a minimum voltage reading from the multimeter, re-filled each battery with distilled water and hooked up a schumacher 1500A-CA 6V/12V car charger to a series of 2 6V batteries at a time, properly connected using a 6 gauge wire in an attempt to create a 12V series.

The charger has an automatic reverse polarity detector so there was no chance they would charge if I had accidentally connected the + and - incorrectly, which I would not have done in the first place.

After 3-4 hours of charge for each set of 2 6V batteries, properly attached to the car charger, the charger showed a green light indicating a full charge. I reattached the batteries using a strap to lower them in, connected them in the same fashion as when I had removed them (I had taken a picture to make sure the wires and polarity were identical) and was ready to test the cart.

All of the 2 battery series read at least 11 volts per the reading on the shumacher car charger, which I had hoped was enough to get my PowerWise charger to a minimum required voltage (26.6V per the manual) to turn on and charge them the remainder of the way once reconnected.

I plugged in the Powerwise charger, but nothing happened. Turned the key, stepped on the accelerator, but nothing. The reverse button sound worked, so I knew there was more voltage than when I started, but I couldn't figure out what was going wrong.

I checked the solenoid with the multimeter to ensure it wasn't faulty, but there were only 23 volts showing. I was confused, since there at least 31 Volts in the series charged set of 6 batteries and I read online that the solenoid multimeter reading was usually 2-3 volts below the total in the batteries if it was working properly.

So I decided to check each battery again with the multimeter and that's when I found the craziest thing I'd ever seen. One of the batteries had reversed polarity. I double checked. I triple checked. I even removed it, tried re-attaching it to the Schumacher as a 6V and the red warning lights started flashing that I had reversed the hook up. I was in disbelief.

It's my guess that in one of the 12V series I was charging using the car charger, one of the batteries was completely dead and the other one still had a little juice left, resulting in a "new" charge reversal creating a reversed polarity.

At any rate, I'm glad I didn't try to charge the cart overnight or hook it up for a long period of time as I'm told fuses would have blown, etc.

My question is this, can I re-label (switch) the battery terminals as + and - and simply try to connect the entire 36 volt series with one of the batteries in a reversed polarity?

I understand the battery probably will not run as long now that the polarity has switched but as someone who doesn't have $600 to throw at a new set of batteries right now, can I give it a shot or are there real dangers involved?

The limited responses I've received so far simply say that the chemical make up of the plates in some of the batteries are different so it might not work as well, but in essence, I have a working battery only with reversed polarity and should be fine as long as I treat the terminals as the opposite as they read (and use some tape and a marker to ensure I do so).

Thoughts? Sorry for the lenghty post, but this is a unique situation and I"ve done a lot of research already to get to this point.

Basically, I just don't want anything to explode so I'm not on the hook for a new golf cart. Thanks.

JC

[scottyb]

It is not as uncommon a problem as you think. It is something that can happen at almost 0 volts. I think you are wasting effort trying to recharge batteries that have sat for 10 yrs. My experience shows 1 yr does about 50% damage and after 1.5 years they never recover. You may get them to hold a bit of a charge but they will not have any usable capacity.
You can take your battery back down to 1v and hit it hard with a bigger charge and see if it corrects itself.

[JCMoney]

Thanks. I basically want to know if I can connect the reverse polarized battery to the other 5, 6V batteries to ensure the rest of the cart is working before we buy the new batteries. I don't need it to run for an extended period, but I just don't want to do it at the risk of injury and/or blowing fuses, etc. From what I read, in theory, I should just be able to flip the battery around and use it as though the positive is now negative and vice versa.

[rib33024]

Wire up 3 - 12 volt batteries = 36 volts to see if it runs. Don't know if the reverse polarized battery will work the way it is, never tried it.
I do know if you get them batteries to charge up some, they will probably drop to 2 or 3 volts when you put a load on them