Will this cause a car fuse blowout?

I have a 120v 7.5A electric drill and I wish to run this off my car's alternator. I'll be using a 12v dc to 120v converter. Would this cause any fuse blow outs?


I plan to drill for less than a minute with the truck running.

Update 2:

Goes into cig socket

5 Answers

  • 2 years ago
    Favourite answer

    Yes, you are pulling roughly 1,000 watts of power which would mean a current of 90 amps. Where are you going to connect this to? The 12 volt cigarette lighter or accessory outlet? Neither of those can supply 1000 watts of mind bending power.

    Your best bet would be to hook this up directly to the battery whenever you go to use it. Chances are it wouldn't blow the alternator because alternators are self limiting in the current they put out. Also, the battery would be helping out as well. But if you don't want to take any chances, then leave the engine off and just use the battery. Then start up the engine every now and then to recharge the battery.

    Just how much drilling are you planning on doing? Are you going to have the drill motor under load continuously for an hour straight or are you going to use it like normal? Normal means you drill a hole for about a minute and then it's another minute or two before you drill again. The lower the duty cycle the longer the battery will last before needing a recharge or the less heating on the alternator if running the engine while you drill.

  • ?
    Lv 7
    2 years ago

    Short answer, it will never work.

  • Anonymous
    2 years ago

    Even if it doesn't blow a fuse it will shorten the life of your alternator by many years.

  • Bill
    Lv 6
    2 years ago


    the drill will use more current than the alternator is capable of producing

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  • ?
    Lv 7
    2 years ago

    Assuming your converter is 100% efficient, you'd need 75A at 12v to give you 7.5A at 120v. In practice, you'd need slightly more. Not only would that blow the fuses, it would probably blow up your alternator.

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