IBM Thinkpad R40 R50 R51 R52 – BIOS CMOS Battery (Replaces Error 0250, 0270)

If your old IBM Thinkpad—like an R40, R40e, R50, R51, or R52—is giving you CMOS errors like 0250, 0251, 0260, or 0270 at boot, the BIOS battery is probably dead.

This is a brand new replacement CMOS battery for those models.

It's the little coin cell that keeps your date, time, and settings saved when the laptop's off.

Unbranded, but it's the right spec.

Keywords on the package say it's for BIOS, time, date, backup—all that.

EAN is 8718475106708 if you wanna look it up.

Easy to swap if you're comfortable opening up the laptop.

Fix those annoying boot errors and stop resetting the clock every time you power on.

Cheap fix, big quality-of-life improvement.