Verify identity and platform compatibility
Read the model plate rather than trusting a similar-looking stock photo. Manufacturers may reuse names across generations with different motors, electronics, battery interfaces, features, and replacement parts. Confirm voltage, regional power requirements, serial plate, and whether the listing is tool-only or a complete kit.
For cordless tools, battery-platform compatibility does not guarantee that every charger supports every pack or that older packs deliver enough current for newer high-demand tools. Check the specific battery and charger models.
- Model and type number
- Voltage and battery platform
- Brushless or brushed motor
- Tool-only versus kit contents
- Regional plug and charger input
Inspect structure and safety components
Look for cracks near handles, battery rails, motor housings, shoe mounts, blade guards, and fastener points. Check that screws are present and consistent; mismatched or damaged screws can indicate prior repair. A tool that has been dropped may run normally while alignment or insulation is compromised.
Do not bypass interlocks, guards, brakes, grounding, or protective covers to complete a test. Missing safety parts should be treated as required repair costs, not optional accessories.
Test controls, sound, heat, and load
Operate every speed, direction, clutch, brake, light, and electronic mode. Listen for grinding, knocking, pulsing, or delayed starts. A brief idle test may not reveal worn bearings, slipping gears, weak brushes, thermal shutdown, or a battery that collapses under load.
When safe, use the tool for a normal light task with the correct accessory and protective equipment. Stop immediately for smoke, burning odor, arcing beyond normal brush behavior, excessive vibration, unusual heat, or intermittent power.
Evaluate batteries, chargers, and repair economics
Inspect battery housings for cracks, swelling, corrosion, damaged terminals, heat discoloration, or repair marks. Charge each pack with the included charger and test runtime under load. Date codes, cycle information, and diagnostic lights are useful when available, but physical safety takes priority.
Before buying, price common failure parts and check whether the tool is economically serviceable. A low purchase price loses its advantage when a proprietary battery, switch, chuck, base plate, or control board costs nearly as much as a complete working tool.
- Replacement battery and charger price
- Availability of brushes, switches, cords, bearings, and guards
- Authorized service or parts support
- Return rights if a load test is not possible before purchase