No, they are tab soldered. It is a toss up tho, if it had replaceable cells it would probably need to be larger.

I had opened one up to see if I could reasonably mount the electronics to a 18650 battery holder. While it could be made to work, it would end up being a lot bigger -- they really optimized the space in there.

Of course, if you are just looking to replace the cells when these ones die, it would probably be a pretty trivial fix to get some new tabbed cells and solder them in.

-john