I can’t find anything on this battery, I searched for a 19500 cylindrical battery because when I didn’t add the cylindrical part it came up with a bunch of phone batteries, but it looks as though you are not the first to wander about or look for this as I found two conversations on the subject. I know these aren’t on the stealth, but it states that they were looking for the 19500 also…
I also found a list of known batteries on Wikipedia and it does not have a 19500 listed under cylindrical li-ion rechargeable batteries…so I think this search may not produce anything you can use and you should probably just consider buying a new one…sorry to be a bummer
Depending on where you are from, there are several places that have decent prices on them…I don’t know if you order from Gearbest, but they have the red/black one for only $16.59 and the black/black and black/white for $27.21 and the blue/black for $31.34
Great! I really wanted to suggest that you get a new mod with replaceable batteries, but I didn’t want to offend you because I thought “well if he really wants to go through all of the trouble of finding this battery and replacing it in his mod that isn’t very expensive to just buy a new one, then maybe he doesn’t want replaceable batteries!!” So I didn’t say anything, but I think that route is your best bet! All of my mods have replaceable batteries because I would hate to lose a mod that I loved just because the battery dies!
https://www.batteriesplus.com/
sorry this place is in US, there may be stores like that in UK? if so walk in and bring the specs of the battery and they can prob replace it cheaper than a new mod.