Use isopropyl alcohol, not a wire brush.

Drop the sandpaper. A quick wipe with 91% isopropyl alcohol on a cotton swab does the job in ten seconds.

Charging contacts get grimy from dust and carpet fibers. That layer of crud insulates the connection, so the vacuum can’t dock properly. You don’t need to scrub or scrape — alcohol dissolves the residue and evaporates clean.

Clean the metal strips on both the vacuum and the charging base. Do it every few months or whenever it starts missing the dock. If the contacts are really crusty, let the alcohol sit for a minute before wiping.

And please, don’t use a metal tool. That scratches the plating and makes it worse over time.

A clean contact is a happy contact. Your vacuum will thank you by not dying in the middle of the living room.