Help! My cordless car vacuum won't hold a charge - Ryobi P714 acting up

Hey folks, having a weird issue with my Ryobi P714 cordless car vac. It's about 2 years old, used maybe once a month. Lately it'll run for like 30 seconds then just die, even though the battery shows full charge on the charger. Tried two different 18V batteries, same thing. No odd noises or anything, just... stalls. Anyone run into this before? I'm handy with wood but electronics baffle me sometimes!

Dave, classic symptom of a failing motor brush or clogged airflow. I restored a vintage Shop-Vac last year that did the exact same thing - would start strong then quit. First, check the filter and hose for blockages (even small ones cause overheating). If that's clear, it's probably the motor brushes wearing down. On these Ryobi units, they're often replaceable if you're comfortable opening the housing. Also - are you using the same charger for both batteries? Could be the charger giving false 'full' readings.

DeWaltDan's on the right track but let's be precise. The P714 has a bypass motor design. If it runs briefly then stops, measure the amp draw when it starts versus when it stalls. Should be steady around 8-10A. If it spikes then drops, that's a short in the windings. Also, those Ryobi batteries have a tendency to develop high internal resistance after 2-3 years - even if they show full charge, they can't deliver current under load. Test with a known-good battery from another tool first. And clean the battery contacts with 99% isopropyl - oxidation causes exactly what you're describing.

Thanks both! Tried my neighbor's Ryobi battery - same issue, so not the batteries. Filter was pretty gross actually (embarrassing!). Cleaned it out but still stalling after about a minute now instead of 30 seconds. Mike, I don't have an amp meter but that makes sense. Dan, how hard are those brushes to replace? I've got my old woodworking tools torn apart all the time but never a motor this small.

Brushes aren't too bad if you've got patience. On that model, there's four Torx T10 screws on the housing. Once open, the brush assembly is held by two clips near the motor - sometimes they're even accessible without full disassembly. Replacement brushes are like $12 on Amazon. But since cleaning the filter helped a bit, I'd also check the impeller for hair/debris wrap. Had a customer's vac last month where a single Lego piece in the impeller caused similar symptoms. If you're near Milwaukee, I could take a look - always enjoy troubleshooting these things!