A 12V windshield wiper motor to run at 24V for more speed but near-equal driving force.

Testing with a variable DC supply between 21.6V & 26.4V showed the current maxes at 3.72 - 3.90A, as opposed to 3.28A with 12V. It did heat up around 24V but only really hot (enough to drop) at 26.4V.

Two of these in the back for drive but speed at 12V isn't enough, how can it run at higher & faster for longer. (Changing the motors isn't really an option.)


1 Answer 1


Running a motor with a higher voltage might reduces its lifetime. However there are some cases where we want to run motors above the rated voltage. According to the equation V = IR, current increases with the voltage since the resistance is contant in a motor. But when it is getting heated, the resistance gets low and the current increases. This process will continue and burn up the motor. Here are some sugggestions to overcome these problems.

Remove the heat of the motor using a cooling system ( Heat sink with a fan, covering with low density oil).

Use a current limiting circuit to avoid drawing more current when heating up.

  • $\begingroup$ without a datasheet, how can the motor's max current and corresponding runtime be tested (without burning the motor)? with this the current limit can be added in addition to the cooling system (while running at higher voltage) $\endgroup$
    – etorobot
    Mar 22, 2019 at 21:34
  • $\begingroup$ If you measure the amps and the temp change in before you get to the burn up stage you can give yourself a rough linear function how much your amps are increasing...or you measure the resistance over time. To get the same. $\endgroup$ Aug 19, 2019 at 17:51

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