Why use a battery board?

There seems to be a lot of confusion and misinformation about my battery boards, what they are, how they work in comparison to other solutions and why they even exist. I hope to clear some of that up today. 

How and Why

In 1999 at TNT it was decided to switch to a lithium battery after experiencing hundreds of boards and therefore complete games being destroyed due to battery acid corrosion. Lithium batteries will not leak and they last longer. The life expectancy of standard AA alkaline batteries in a pinball machine is roughly one year. If they die it’s not a big deal, you lose any settings and high scores and you can simply change them the next time you play. If you forget and/or the game sits or goes into storage for any length of time the problems begin because the batteries will eventually leak. 

A lithium battery will last about 5 years and in some cases considerably longer. Again if it dies no biggie, change it and program back in your preferred settings. If the game goes into storage for 10 years you won’t have to worry about your game being destroyed and completely acid corroded. That being said if you are knowingly placing your game into long term storage it’s always a good idea to completely remove all batteries. 

The lithium battery that was used at the time as a ½ AA cell with wire leads on it. The original battery holder was removed and .156 KK series Molex header pins were mounted on the board. Matching trifurcon crimp pins were placed on the battery and it was mounted on the board. This worked quite well for almost 15 years. The only reason it was deviated from is because the batteries we used were sourced from an industrial battery supplier and not readily available to the general public, also they did not have the required ends mounted for installation. Because of this the customer had to call in and buy a replacement battery which cost about $15 including shipping. The batteries were being sold at cost so time was also being wasted taking the call, billing the credit card, getting the battery ready and shipping it out.

While working on some Golden Tee boards we came up with the idea of trying coin cells on the boards, they are cheaper and customers can buy them when doing regular shopping. We started by simply mounting the cell holder in existing holes and running a jumper wire. In some instances, depending on hole spacing, a hole had to be drilled to mount the coin cell holder. After a while this became a pain and I came up with the idea of mounting the battery and holder on a piggyback board that could simply be soldered into the existing battery holder holes. Because of differences in the battery holders manufacturers used across different board systems I designed one board that could be adapted to fit multiple games and systems. By doing this I was able to keep costs down by minimizing the number of different boards I had to make. Even though it’s not completely necessary, I decided to add an additional blocking diode in the event the glass diode used on System 8-11 as well as WPC games shorts. If you are using a battery board on the early Bally or Stern games the diode is needed since those games were originally equipped with rechargeable Ni-Cad batteries. I simply added the diode as an additional protection and convenience for my customers. 

Other solutions

NvRAMs are another option, they aren’t always the simplest or the most cost effective. For one, they don’t preserve the function of the Real Time Clock (RTC). While it’s not a necessary function for most games, I believe that most collectors want their games to function as designed. Also not all RAM chips are socketed making installation more difficult. If the RAM is socketed, it could still have acid corrosion or be worn out and not hold the NvRAM tightly. NvRAMs can and do fail. I understand batteries die, but they are much simpler and cheaper to replace. Don’t get me wrong, I have nothing against NvRAMs, I have used them in the past and may even make my own in the future.

Another option is remote battery packs. To me this is the most ridiculous solution. When the board has to come out for service you either have to disconnect it meaning all of your settings are going to be lost, or you’ll have to work on the board with a battery pack flopping around. And if you think a remote battery pack is going to save you from acid damage, it won’t. It will only buy you time. I have seen several instances where acid has traveled up the wires. See the pictures below where the pins pulled out of this connector because of acid corrosion. 

My battery boards fit into the existing battery holder location. The fact that it has to be soldered in is due to the design of the game, not my boards. They stay permanently attached to the board, require no modifications and can easily be removed when someone is willing to pay you 5 grand more for your game if it had the original AA batteries. I take every step I can to make all my boards a complete solution and as easy as possible for you, my customer and it comes with a battery. I also want to point out that I donate $2 for every board purchased from this site to Project Pinball.  

One last point I want to make is a lot of people are making claims about the voltage differences between three AA battery packs (4.5v) and the CR2032 coin cells used in my battery boards (3.0v). They are also claiming that the CR2032 won’t last as long due to the fact they have less milliamps. I had one guy comment that he prefers to use the AA batteries due to the advantage of having 4.5 volts as opposed to just 3 volts. Advantage? What advantage? Does he think 300 million points are going to be added to his high score every time he turns his game off or something? The fact is both of those claims are wrong. Over 6 years of real world testing has proven 2 things. The first is that 3 volts is adequate to maintain game memory during power down. The second is that the CR2032 coin cell provides enough milliamps to last about 5 years. I think the reason the coin cells outlast the AA alkaline cell is due to the chemical composition differences of the two, although that’s purely speculation. 

At the end of the day it’s your game, use whatever solution suits you best. Just be sure to forever rid yourself of those AA alkaline batteries. Thank you and happy pinballing! 


Readers Comments (1)

  1. Great and informative post. Thank you for a marvelous game saving and very affordable invention!

Leave a comment

Your email address will not be published.