Tried an on line search. I suspect it has a smaller battery inside. I gutted my old Delco (finally bit the dust) and installed a Braille battery upside down. Still going strong. I have four Braille batteries, and really like them.
https://www.yenko.net/forum/showthre...headed%2Asouth
Like I said, I did an on line search, and could not find any info on what battery is inside. Likely the only way to find out is to buy one and cut it apart. Not a great option. Although if someone on this site would like to do that, I would pony up the first $20 just to find out. Get 15 other guys to to that and you are set.
There is a discussion over on Yellow Bullet about the 16v versions. The consensus is that they don't last long.
https://www.yellowbullet.com/threads...arger.1837170/
Good luck.