How to Repair an Optima Yellow Top

[bennelson]

Recently, I had a problem with one of the Optima batteries on my electric motorcycle.

I shorted out a post and melted it.


Today, I finally had some time to work on the cycle. I cleaned up some of the wiring and decided to fix the post too.

The first thing I did was cut the post off, as it really wasn't needed, because Yellow Tops have side posts as well, which is what I was using.

Of course the instant I cut the post off, the cycle no longer worked. Turns out that Optimas actually connect the cells internally through the POST!

So even though I cut the top post off, now the side posts no longer worked!

I called the battery store, where the guy informed me about the internal connection through the post. He also said there was no way to fix it, I just wrecked it, and by the way, I just lost my warranty too!

After getting off the phone, I got into an angry "I'll show him" mood.

I drilled a hole through both what was left of post and the bit I cut off.


I then tapped both parts.


I threaded a bolt through both parts and tightened it down.


Then I hit it with a torch to melt the lead back together, bit it was not narrow enough of a flame, so I finished off melting the lead seam together with a soldering iron.




Turned the cycle on - worked great again.

So there you go. Fix a $160 battery with a 10 cent bolt.

Take that! dude at the battery store!






(Please note that anytime you work with lead, don't breath any fumes, and wash your hands well after working. When working with batteries, always know where any conductive tools are and what's positive and negative!!!)

[Red]

Nice fix. Why bother sticking the old post back in? I'd have just used the bolt with a nut

[Duffman]

I think it took a lot of balls to fix a battery. Dont know if that is a gel-cell or not but putting a torch to a conventional battery should be on the not to do list. Lethal level current, acid and explosive gasses all make batteries pretty dangerous IMO.

[cfg83]

Duffman -

Originally Posted by Duffman

I think it took a lot of balls to fix a battery. Dont know if that is a gel-cell or not but putting a torch to a conventional battery should be on the not to do list. Lethal level current, acid and explosive gasses all make batteries pretty dangerous IMO.

Would the "cold heat" option have worked for melting the solder or is that even more dangerous ?!?!?!?!?

bennelson -

Great fix!

CarloSW2

[Duffman]

Maybe the OP has the background and knows what he is doing but IMO fixing a battery is not a DIY repair and should not be represented to be one. I am not sure you are aware or not but batteries can explode, any of the the mechanics on this site probably know of someone that is has happened to.

[dcb]

Whatever Duff. Good job Ben!! Do keep the torch (and possible sparks) away next time though

[AXMonster]

Could have got a battery terminal of a scrapper & used that to replace the burned one... would have looked better. Good job though. This is what i did to convert my race battery with 6mm threads to a post type.

[SatanicMechanic]

You can buy a standard post battery converter terminal (marine to standard post). Instead of using a bolt, use some ready-rod (all-thread to you Western Washington types) and screw on the new terminal. Of course your method is cheaper.

[Johnny Mullet]

If I recall correctly, I was the one who said to just cut the bad post off assuming this battery was similar to all automotive/marine type batteries.

Good save!

[bennelson]

My home repair of the battery lasted all summer, then one day, it just plain stopped working.

I know I have posted about the "professional" repair I had done on it, but I can't seem to find that post anywhere!

Anyways. What I did was call around, and I eventually found a battery shop that said to bring it in and they would look at it.

The guy took a quick look at the battery, then started working on it.

He cut the post off even with the top of the plastic. Then he took a very large drill bit (about the same diameter as the entire post) and drilled straight down into where the post was. This was only a shallow drilling, just enough to get the outside edges of the drill bit into the lead.

Then he pulled out a little metal form with a handle, and a base cover that looked like a large washer. The washer went around the hole, and then the tube-form went over the top of that.

He pulled out a lead stick and melted the end of it into the post-shaped mold. The oversized washer was apparently to protect the plastic from the heat, it may have also helped seal up the bottom edges of the mold.

He let it cool a few seconds, and then pulled the mold off.

Poof! Brand-New Battery Post! Better than new actually! He said the new post was a solid casting, and the old one was cast in two parts, which was part of my problem with the shorting in the first place!!!

The whole process of recasting the post took maybe 5 minutes. That's the advantage of having the tools and experience!

While the guy was going it, I told him about the motorcycle, electric car, and other projects I was working on. He was very interested, and really suprised I could get a forklift motor to drive a car to 45 mph!

When he was done, I asked how much I owe. He relied that there was no charge, but just come back to him when I need to buy some batteries!



PS - For my original battery repair, the battery is an AGM, so it's sealed (maintenance-free) but does have vents on it that will open in the case of extreme over charging. I had not recently charged or discharged the battery, and I was out in the open air. The battery repair guy used an acetylene torch for recasting the post and didn't seem to use any special precautions, other than just not getting too close to the plastic shell of the battery.