These guys seem to have a fairly decent lifespan!
Ive done about 4-5 field recording sessions with a Zoom H6 powering a Rode NT4 with Phantom Power, and there's still plenty of life left in them!
I will, however, not be purchasing again due to environmental considerations - maybe Thomann could look into stocking Eneloop rechargeable batteries - which I have chosen as a replacement for one-use batteries.