The bad battery thread


Mr Neo Fix-it
Time for a reminder that everyone should check their NiCd batteries for leakage!

The solder joint should look nice and shiny and the end of the battery should look clean, like this:



BOTH ends of the battery must be checked. If the Negative side looks like this:


Then the battery MUST be replaced. Notice the fuzzy growth on the end of the battery? Is it dust? NO! The battery is leaking.

How can you tell it's not dust?

Easy. Look at the solder joint on the board. See all that crystalline fuzzy growth on it? THAT is from the leaking battery and is not dust. Compare that picture to the first one. Those are 2 pics from the same battery. BOTH solder joints should be clean and shiny.

This battery must be replaced. (and in this case was... this was a board fixed for a forum member)

If your board looks like this, then it may be too late to save:


If you have pictures of leaking batteries on your game board, post them up for everyone to see. Sometimes the only clue of a leaking battery is a discoloration on traces near it, such as when a battery just starts to leak on a 4 slot board.

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Great post Kernow's dead DDP DOJ board saved my 4 slot MVS.

I hadn't thought of it in forever but got me to take it apart and look. I thought it was fine at first but once I got the battery out I could see some residue. I neutralized it with baking soda and cleaned it all up.

I left it out though because that is the extend of my skills. What would you charge me to do a proper battery mod on the board? I'd like one that doesn't hang out... and doesn't need to be charged or anything.


Xian Xi

This is the one that was on a CMVS I bought, no wonder it was cheap. It still has RAM problems so I need to swap the RAM, too.



Crossed Swords Squire
Aww, rats.

You were just a few hours late on this thread. About two weeks ago, I purchased a pinball machine. I'm busy so it took until yesterday to get to the battery.

The battery looked OK from the front and still saved information. Flipped the board over...and fuzzy corrosion on the solder points for the battery. No other corrosion anywhere else as far as I could see. Close one.


Whilst Drunk., I Found God., Booze = Bad.,
i need to order some varta batteries....this thread is like a defensive driving video with gruesome deaths....but MORE horrifying.
I think some other beneficial information would be around care and feeding of these batteries. I can't say I really know enough about them.

-I know they are rechargeable so they rely on being powered up from time to time. How much is enough?

-If they sit in storage for months at a time do the batteries die faster than if they are used more frequently?

-Aside from seeing signs of failure, is there some testing we can do to make sure they are good? I recently got a board with a varta 3.6 and I have no idea how old it is. If I measure, it's putting out 3.6V. Am I good?

There's probably some other stuff, but I'm thinking there has to be some recommended care and feeding, and some troubleshooting other than "hey look it started leaking all over".


Mr Neo Fix-it
The boards should be powered up for a day each month if you want to keep the batteries charged. They can keep the charge longer... it just depends on the current draw and the internal resistance (which slowly drains the battery even when not connected to anything) of the NiCd cell.

Once the solder joint starts looking fuzzy you are already on the path to doom. The solder joint will look fuzzy before the end of the battery does.



Just Short..., As always... :-(,
+1 on the STICKY for this extremely useful information.

Thank you for the heads up:buttrock:

RJ & Xian's photo's are perfect examples of neglect/forgetfulness
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Krauser's Shoe Shiner
+1 for sticky as well. I'm checking more board tonight when i get home from work. As someone who hasn't soldered a thing in his life, is installing a new battery a difficult task? I know soldering pros and can take it them, but I'd rather try and get my feet wet and some point.


Sieger's Squire
Does it matter what brand of battery you use or is it all about the mAh? I recently replaced a few cps-2 boards with XenoEnergy XL-050FAX, all of which had maxells (original?)


Giga Shock!!
Of course the brand doesnt matter. The voltage is what you need to look at.

mAh == milliamp-hours.. The higher this number is, the longer the battery will last without needing a recharge. However, I don't recommend you install a rechargable.

Use a lithium in series with a diode to stop the current from the board reaching the battery. It'll last for years and you won't need to worry about firing up your board every so often to charge it.
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Armored Scrum Object
Batteries Plus

And a number of other places.


How about in the UK? Can't seem to see anything suitable on the Farnell or RS sites where I usually buy my components from.

Edit: Scrub that, have the Varta 3/V80H - product code: BN22Y
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