That Bally Video TwentyOne battery...

[shortrackskater]

I need the proper 3.6 battery for my ancient and working Bally Video TwentyOne.
I mistakenly bought aB40H battery on eBay a year or so ago, thinking (not looking closely at the photos) it was correct, when in fact it's a side stacked parallel wired pack of 2. I got a single stack. And it's not holding a charge.
I really don't feel like making one up - does anyone have this? Sadly Gary had a supply of them, but...
Photo of proper battery added. 

[Chris-socal]

I doubt it being a single stack would make it fail to keep charge completely unless you are saying it was supported to be a 7.2v battery. Was the original a nicad battery?
If I recall they used those parallel or just bigger cells because nickel batteries didn’t hold as much back then.
We used big nickel batteries in RC cars in the early 80’s. By the 90s the nickel cells had 40% more capacity. Then came along nimh, then came lithium. Every generation was physically smaller but held more charge. You might want to connect a dvm to the leads while the game is turned on to verify it is charging.

https://www.ebay.com/itm/233947589446?hash=item36785ceb46:g:wnYAAOSwiu1c9R1y&amdata=enc%3AAQAIAAAAwKuKezwTPq2yCTfwLXg%2FuFik33NgIsu0bWS64m0Hzd9TZz00Sp%2B6XCBylqJNLJAOwiFaqrDZDUz%2BicBLnCeNmrbDYDm%2BX3Ds%2FNfgN%2Fb6oKaLM4fvOg88LjQMwFjE1x0G570KNWlA4T5BWGQkSmeMphD4ZDMZpXMmzEJbqau6NkdKIJfFhXUcUOHAjcfA1Fal3A9kePR%2F8YkrBMqS7Y3YGCIhzUI5uegZDZ0bNx%2FMDClOK9EwQQxEAIjLf9GA35Ey5w%3D%3D%7Ctkp%3ABk9SR8Ctr6XjYg

[shortrackskater]

Hi Chris
I don't turn it on all that often but more often now and it seems to be ok. I should try tonight but I'm SICK! I bragged that I have't have anything for 3.5 years so I guess it's coming back to me. I'm really sick: Had a fever but now have aches, chills and horrible pain. I just ordered from instacart and nearly lost my balance walknig done my driveway.  I'm still actively speed skating and my balance is usually impeccable.
Alan send me a PM with the following information. I had forgotten about this mod and may try it.

Replace the leaky green battery with a 3.6 V Lithium Ion battery with wire leads.
You only have to do one change to the board.
Find 3 resistors together where the middle resistor is marked "opt 1".
Remove that resistor and you will see a diode symbol under its place.
Install a 1N5817 diode in those 2 holes.
The 5817 has a lower forward voltage so more voltage reaches the RAM chip.
In comparison a iN4001 has a .5V forward drop.