Cordless Drill to Wall Outlet

Discussion in 'The Projects Forum' started by SullivanSwitch, Sep 16, 2012.

  1. SullivanSwitch

    Thread Starter New Member

    Sep 16, 2012
    Hello All,

    I recently was gifted a second-hand Skil cordless drill and tool set. It came with two batteries, one of which worked. So I had the idea to take the batteries out of the battery-pack which wasn't working, drill a hole for a power cord, and "whamo"; corded/cordless drill.

    Now I've always like playing with electronics, but my understanding of electricity & such is mostly limited to "hurts bad, don't touch..". So, I was wondering if anyone could explain, as if to a child, how I can turn a wall-outlet into 18volts of constant, non-pulsing DC. I really hate to just ask something like this without trying to do my own homework before hand, but the hours I've spent online trying to understand my own project has only led to 1000mg of Tylenol haha...

    Any hints to set me on the right path would be greatly appreciated.

  2. PackratKing

    Well-Known Member

    Jul 13, 2008
    A full-line computer equipment store, may be able to hook you up with a "wall wart " with appropriate voltage and current potential - tho' matching the plug into the drill may be an issue.
    I would have to measure my B&D 18v. drill, to be certain of the amperage draw requirement, tho' an educated guess would think at least 5 amps, due to the fact the motors in those multiply torque with planetary gearing, which helps keep amps reasonable.
  3. #12


    Nov 30, 2010
    Don't be too concerned with the "constant, non-pulsing" part. DC motors don't care (much) about the cleanliness of the current.

    The most difficult part would be trying to stuff all the proper parts in the size of the empty battery holder. (The transformer alone will probably not fit.) That's why a completely external power supply is a good answer. And my guess about the current is more like 10 amps. Try to measure the current from the good battery pack under stall conditions. If it blows the fuse in your "typical" 10 amp DC current meter, you will need at least a 10 amp wall wart.
  4. vk6zgo

    Active Member

    Jul 21, 2012
    It's a waste of time trying to run it off the mains using a power supply ,real mains operated drills are dirt cheap,and have way more "grunt" than battery types.

    What you can do,is make an external battery pack which you can recharge as required,so the thing will be almost as portable as it was with the internal batteries,but have a lot longer battery life.

    "Silicon Chip" Magazine in Oz,had just such a mod several years back.