Could not find information on the Internet can I replace the batteries in Profoto B1. Replace Lithium-Ion elements.
Took a chance and got a good result.
Now the old battery gives out 325 Full-Power Flashes, like a new battery for Profoto B1X

Total cost 40$ — 1 battery.

Old pack — Samsung INR18650-15M — 1450 mAh

Sanyo/Panasonic UR18650NSX 2600mah