DEWALT DCG418X2 54v Flexvolt Brushless 125mm Grinder with 2x9ah Batteries

There’s plenty to think about when choosing an Angle Grinder. The first factor is the disc diameter; larger discs can make deeper cuts.
Then consider how much power you might need. Higher wattage tools provide more power and can therefore cut denser material. Then think about speed; some grinders operate at fixed speed and others have variable speed control. Being able to vary the working speed of your grinder enables you to carry out more delicate work.
Another factor is whether the tool is equipped with safety features, such as a Paddle Switch and Soft Start.

Brushed motors use carbon brushes to transfer power from the fixed part of the motor to the rotor. This creates a reliable and relatively inexpensive motor, but brushed motors do require regular maintenance, in order to either clean the brushes or replace them as they wear out. A brushless motor, by contrast, uses a magnet mounted on the rotor to generate the power and electrical switching to perform the function carried out by the brushes. The additional complexity of the motor’s working means that brushless motors are usually more expensive than brushed.

The work you’ll be doing with your grinder will influence which voltage you consider. If your grinder is going to be used for construction, you may want to think about choosing a Makita 40v or DeWalt 54v tool, but 18v variations are also available.