Ikelite lithium batteries and charger

Several years old, they worked last time I used them, but they weren't lasting very long, hence the low price. Includes one charger for lithium in great shape. $75 shipped in USA

https://www.ikelite.com/blogs/faq/batteries-chargers-for-ds161-ds160-and-ds125-strobes

Ikelite killed off these LiON battery packs and was running an exchange program for them for a while. Not sure if that's still available. You might want to see if you can get them replace by NiMH packs.