Can anyone recommend a good replacement battery for GBA SP?

[matt]

deja vu…

the battery I bought and mention in this older thread is still going strong!

Best replacement battery for GBA SP? (AGS-001)

My GBA SP AGS-001 battery only lasts about 4 hours per charge these days. I know it was originally capable of so much more. Can anyone recommend a reliable replacement battery they’ve used that performed well?