Will this grinder handle brake dust and rust removal?

Yes. Use a wire wheel or abrasive attachment in rotary mode. Start at lower speed on aluminum or soft materials to avoid gouging. Test on a scrap panel first if you're new to powered detail work.

How long does the 3.7V battery run on a single charge?

Runtime depends on attachment load and speed setting. For light polishing or wire wheel work, expect 20–40 minutes per charge. Heavy grinding drains faster. Keep a second battery handy for longer jobs.

Can I use standard rotary tool bits and wheels with this grinder?

Yes, it accepts standard attachments. Confirm shaft diameter matches your bits before purchase. Most common polishing pads, wire wheels, and grinding stones fit without adapters.