Slim Pen reporting a battery error

That symbol is actually a warning triangle/exclamation mark, not an “i.”

The 6% means your Surface Slim Pen 2 battery is very low. The warning symbol indicates that there may be an issue with charging, but it doesn’t necessarily mean the charging slot is faulty.

First, place the Slim Pen 2 properly in its charging slot and keep the Surface connected to the charger. Then check whether the pen starts charging.

White LED fading in and out: the pen is charging normally.

Amber LED: the battery is very low.

No LED: there may be a problem with the charging connection or the pen itself.

If the battery remains at 6% after 15–30 minutes, then we should investigate the charging slot and the pen's battery.

The easiest way to identify the problem is to try another Slim Pen Charger, if you have access to one. If the pen charges normally with the separate charger, the problem is likely with the keyboard's charging slot. If it still stays at 6%, the Slim Pen 2 itself may have a battery or charging problem.