Cordless Phone Battery Replacement

So these cordless phones I have use 2xAAA and they’re not holding charge anymore. I could either
-buy a new replacement battery
-buy AAA rechargeable and solder/wrap the cells in with the existing terminals.

Has anyone tried option B?

Yes, I have done this and it works. Be sure to replace NiCad with NiCad or NiMH with NiMH just for piece of mind.

I’d buy some Eneloop AAA and wrap them in there. They can be had with solder tail.
They sell them here as complete batterypacks with Eneloops inside instead of the OEM ones.