I have put lithium batteries in all of my factory test fixtures back on December of 2011, and they are still going strong.
My thought on using lithium batteries instead of 3 AAA batteries, is if I can get a year out of them, I was going to be happy, and started putting them in all my games since December 2012 and they still have 3 volts.
I have seen so much acid damage done by 3 AAA batteries leaking, I seen 3 AAA batteries less than 2 years old with 1 AAA dead and leaking and destroying the CPU, and game still booting up because it still had 3 volts to boot the game up. I have seen the vapor from leaking batteries in a remote battery pack do damage to boards also. Gottlieb has used 3 volt lithium battery in all of their System 3 games , and they don’t go bad until almost 20 years later, and none of them had leaked to do any damage.
To make it look clean when putting mounting a Lithium battery, run the ground wire jumper on the back side of board.

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