For a few years I have been using an Owon SDS7102v mains/battery labscope and have had problems with the official Owon battery packs holding charge. As the scope is fairly oldschool and power hungry this was a pita especially as official packs use lithium gel flat pack cells and aren't cheap.
I had spotted a low conversion on AliExpress to use standard round lithium batteries pre-covid so did a search on Ali-Express and ordered one.
When it arrived I loaded it with freshly charged batteries and it is working very nicely.
I fitted using parts of the dud battery case and it sits quite nicely and securely.
" We're trying to plug a hole in the universe, what are you doing ?. "
(Walter Bishop Fringe TV show)