When it comes to buying battery-powered yard tools, it may be hard to truly understand how powerful they are. So, what do you really need to care about when comparing tools? Make sure you’re buying the right tool for the job by understanding 10 basic aspects of battery-powered tool power and performance.
1. Brushed Motors
Brushed motors employ a mechanical switching mechanism (or commutator) to turn the motor; whereas brushless motors rely on a controller to perform this same function electrically. These motors have been around a long time and are generally reliable. They have a simple design and are therefore less expensive. There are definite advantages to a brushless DC motor, but in the right application, a brushed motor is sufficient for the job.
2. Brushless Motors
Brushless motors are lighter and more efficient, but slightly more expensive. When reviewing different battery-power tools, efficiency and weight are two critical specs to consider. Unlike brushed motors, brushless motors do not have a wearable brush limiting the life, so products using brushless motors have the potential to outlive their brushed counterpart. Because of this reason, the industry is making the shift to brushless.
Voltage is often understood to be the dominant rating on most electric tools; however, the true measure of power in a power tool is wattage.
Watts = Volts x Amperage
Batteries are rated in amp-hours. Think of an amp-hour rating as the size of your gas tank. For instance, a 5 amp-hour battery can discharge 5 amps continuously for one hour.
For Example: A 2.5 Ah battery will do half the work of a 5 Ah pack.
- When comparing tools, also look at a battery’s watt-hour calculation. Watt-hours generally can help provide an idea of how much total power a tool can deliver overall.
- Toro’s new PowerPlex T90 lithium-ion battery provides a baseline of 36 volts multiplied by 2.5 amp-hours, which is about 90 watt-hours.
Watt-Hours = Volts x Amp-Hours
5. Estimated Run-Time
Run-time varies by tool and the job you are doing. Toro’s new PowerPlex batteries have an on-board power meter that shows how much power is remaining. It’s important to note that variable speed can also impact run-time.
For Example: Toro’s new PowerPlex 13″ string trimmer/edger can get about 45 minutes of runtime, which is plenty for the average-sized yard in urban and suburban areas.
Variable speed tools are, as you would expect, variable in speed. Generally, in battery products they are infinitely variable. This gives you the ability to finely control the power of the tool. However, in some tools this may be a nuisance, so some products offer a “throttle lock” like a cruise control.
Some products have 2 or 3 speed switches.
Products offering a “boost” mode generally require you to hold the button down for continuous high output. These boost buttons are used mostly for stubborn chores that need a little extra power. Running in boost mode the whole time will deplete the battery much faster.
7. Added Functionality
- You may want a trimmer that has dual modes, so you can switch between yard tasks easily and quickly.
- Toro’s new PowerPlex 13″ string trimmer features a button that twists the head of the tool, transforming it into an edger with a walk-behind wheel.
Miles per hour (MPH) rating can help assess the power of a blower but is not a good measure of power alone. It is possible for a 230 MPH blower to have more power than a 240 MPH blower, because a blower’s CFM also is taken into consideration to determine overall power. The size of a blower’s nozzle opening impacts which yard tasks it is best suited for.
For Example: A blower opening the size of a straw could blow air at 300 MPH—it is good for clearing out cracks in the driveway, but not good for blowing leaves in your yard.
- Cubic feet per minute (CFM) is air volume from a leaf blower in one minute. Sufficient CFM is important so homeowners have enough pressure and air output to move debris or leaves.
- Many yard tasks require both air speed (MPH) and air volume (CFM) so homeowners should look at both factors when purchasing a blower.
The most powerful blower will be one that maximizes both MPH and CFM.
10. Air Horsepower
Air horsepower can be thought of as general force — it is the combination of CFM (volume) and MPH (speed), which is the measurement of the amount of work the blower’s air stream can do.