Craftsman 24 volt batteries

I know that a lot of threads have dealt with the interchangeability of batteries across manufacturers. The one system I am trying to keep out of the landfill is my 24 volt, Craftsman string trimmer. The replacement battery goes for over $70. I didn’t pay that for the whole kit.

If anyone has been tinkering with the Craftsman 24 volt tools or batteries, please let me know what you have learned. Thanks!