We should mention the increasing popularity of brushless motors in the cordless tool market.
Brushless motors operate in a significantly more efficient way than their conventional ‘brushed’ counterparts.
They use modified components and a small electronic sensor/controller in their motor to eliminate friction (always a by-product of a brushed motor) and thus deliver more power.
The amount of power that is delivered is also controlled by the amount of resistance the drill encounters.
The brushless motor only generates as much power as it needs.
Traditional brushed motors on the other hand will always deliver the maximum power they can, when fed the same amount of current.
Note however a brushless tool can never deliver ‘more’ power than a brushed tool running from the equivalent voltage battery.
But by eliminating the friction a brushless motor runs cooler, more efficiently and quietly and with less vibration than a brushed motor.
Using an example from the DeWalt website below you can see this extra efficiency translated into usage when fastening screws.
The brushless motor also sees greater longevity because its mechanical components are less likely to fail.
These benefits do come at a cost though – approximately 30% more than the equivalent tool running with a brushed motor, although having said that prices of brushless tools have decreased significantly in recent years.
The cost Li-Ion batteries also needs to be taken into consideration when considering a brushless power tool.
In general you need to be quite a serious power tool user or professional to justify a brushless version, unless of course cost is less of an issue and you just want the luxury of having the best tool for the job!