Hmm usually Lithium polymer in a soft pouch. If there are 2 wires it is not too problematic, as these are bare cells. If there is a third, then inside the 'battery' is at the least a temperature sensor, and in some cases a management chip. It is often possible with care to do giblets transplants int a new pack but it is a delicate soldering job and not for the faint of heart.

In this case I think the protection circuit is on the main PCB under the gold-coloured 'kaptan' style tape.

There is no universal numbering but where there is a standard of sorts it is to use the dimensions in mm as a part no with the thickness in units of 1/10 of a mm.

Does any of the documentation mention the battery capacity in mA hours ? apart from  cell type,  that is the main thing to get at least roughly right, I would not recommend it for professional use, but I  have done repairs for home items where I  have simply hot-glued a cell of the wrong shape but the right capacity on the outside of the case and led wires inside.

Mike

Hmm usually Lithium polymer in a soft pouch. If there are 2 wires it is not too problematic, as these are bare cells. If there is a third, then inside the 'battery' is at the least a temperature sensor, and in some cases a management chip. It is often possible with care to do giblets transplants int a new pack but it is a delicate soldering job and not for the faint of heart.

In this case I think the protection circuit is on the main PCB under the gold-coloured 'kaptan' style tape.

There is no universal numbering but where there is a standard of sorts it is to use the dimensions in mm as a part no with the thickness in units of 1/10 of a mm.

Does any of the documentation mention the battery capacity in mA hours ? apart from  cell type,  that is the main thing to get at least roughly right, I would not recommend it for professional use, but I  have done repairs for home items where I  have simply hot-glued a cell of the wrong shape but the right capacity on the outside of the case and led wires inside.

Mike