In addition to the electrical performance and characteristics of the cells, the SAFT has additional qualities that puts it on our “approved list”;
Stainless steel container and end caps (low magnetic signature)
Hermetic glass-to-metal sealing
Low self-discharge rate
Compliant with EN 50020 intrinsic safety standard
Selecting the wrong one will cause problems. Only use the correct battery as indicated by the manufacturer unless you are sure of the equivalency.
Some functions of the handset can pull a large amount of current, such as the alarm screen indication which can exceed the maximum recommended continuous current of the wrong cell.