My DeWalt grinder keeps stalling mid-cut - battery issue or something else?

Hey folks, having a weird issue with my DeWalt DWE402 grinder. It's about 2 years old, been solid until now. When I'm cutting metal (mostly rebar and angle iron), it'll just stall out halfway through. Battery shows 2 bars left, but acts like it's dead. Tried my other battery - same thing after a few minutes. No weird noises or smoke, just stops. Any ideas before I drop cash on new batteries?

Classic DeWalt battery problem man. Those 20V Max batteries are expensive to replace. Before you buy new ones, try cleaning the contacts on both the tool and batteries with some rubbing alcohol. Also, check if the batteries are under warranty still - sometimes they'll replace them for free if they're failing early. If you DO need new ones, wait for the holiday sales at Home Depot, they usually have 2-packs for the price of one.

Stalling without load or during cutting? Important distinction. If it's stalling DURING cutting, it could be brush wear or armature issues, not just batteries. DeWalt grinders typically draw 10-15 amps under load - weak batteries can't sustain that. Use a multimeter to check battery voltage UNDER LOAD (not just resting voltage). Also, inspect the brushes - if they're under 1/4", they need replacement. Proper maintenance prevents 80% of these issues.

lol I feel your pain! My old corded grinder used to do something similar when the extension cord was too thin. But since you're battery... Steve's probably right about checking the brushes. I had a similar thing happen with my orbital sander last year. Turned out the brushes were shot and it was creating extra resistance. Cheap fix if that's it - like $15 for brush kit on Amazon. Way cheaper than new batteries!

Paul's got a point about the brushes being cheaper! But honestly, if it's under warranty still, make DeWalt fix it. Their customer service is pretty good in my experience. Just be ready to wait 2-3 weeks for repair turn-around. In the meantime, maybe borrow a corded one from a friend if you've got projects waiting? Harbor Freight has cheap corded grinders that'll get you by in a pinch for like $30.