A cordless angle grinder is a versatile power tool that is powered by a rechargeable battery rather than a corded electrical outlet. It's used for a variety of applications, including cutting, grinding, polishing, and sanding different materials like metal, stone, tile, and concrete. Here's a detailed look at the features, benefits, and considerations for choosing a cordless angle grinder:

### Features
1. **Battery Type and Voltage**:
   - Common voltages range from 18V to 60V.
   - Higher voltage typically means more power and longer runtime.

2. **Motor Type**:
   - Brushless motors are more efficient, offer better performance, and have a longer lifespan compared to brushed motors.

3. **Disc Size**:
   - Common sizes include 4.5 inches, 5 inches, 6 inches, and 7 inches.
   - Larger discs can cut or grind larger areas faster but might be heavier and harder to control.

4. **Speed**:
   - Measured in revolutions per minute (RPM). Typical speed ranges from 5,000 to 10,000 RPM.
   - Variable speed options are available on some models for better control over different materials.

5. **Safety Features**:
   - Electronic brake: Quickly stops the disc when the trigger is released.
   - Kickback protection: Detects and mitigates sudden tool movements.
   - Overload protection: Prevents the tool from overheating and extends battery life.

6. **Additional Features**:
   - Adjustable guard: Helps protect the user from debris and sparks.
   - Ergonomic design: Comfortable grip and balanced weight distribution.
   - LED indicators: Show battery level and tool status.

### Benefits
1. **Portability**: No need for a power outlet, making it ideal for outdoor or remote jobsites.
2. **Convenience**: Easier to maneuver without a cord getting in the way.
3. **Flexibility**: Suitable for a wide range of applications with interchangeable discs and accessories.

### Considerations for Choosing a Cordless Angle Grinder
1. **Battery Life and Charging Time**:
   - Check the amp-hour (Ah) rating of the battery; higher Ah means longer runtime.
   - Consider the availability of fast chargers.

2. **Power and Performance**:
   - Ensure the grinder has enough power for your intended tasks.
   - Look for models with brushless motors for better efficiency.

3. **Ergonomics and Weight**:
   - Heavier grinders can be more tiring to use, especially for extended periods.
   - Look for models with comfortable grips and well-balanced designs.

4. **Accessories and Compatibility**:
   - Check the availability of compatible discs and attachments.
   - Some models come with additional accessories like extra batteries, carrying cases, and various disc types.

5. **Brand and Warranty**:
   - Reputable brands typically offer better quality and service support.
   - Consider the warranty period and what it covers.