Don't-it-yourself: USB drill-charging adaptor
- by Ryan Carter (RSS feed) on Aug 22nd 2007 3:00PM
- Filed under Don't-it-yourself
Welcome to the first ever episode of DIY LIfe's don't-it-yourself, where we showcase a DIY project gone wrong or didn't work right for one reason or another. DIY can be the boon or bane of your existance, depending on the idea, the time and effort and even sometimes I've heard, Murphy's Law. Today, I raise my own hand and claim ineptitude, yes, if you must know, this DIY project was mine.I am a computer guy, and so to me, everything, yes everything can be solved with some type of computer hardware or software, or both. I have a computer solution that will eliminate world hunger, but unfortunately I haven't had a chance to work on it much, so I'll get back to you on that. I try to fix everything with my knowledge of computers. Most of the time it works like a charm. Sometimes it doesn't.
I tried to do make a USB-powered charger for my household cordless-drill, since I had lost the factory shipped power adapter (I know, my bad). While not a terrible idea, I admit it may have been poorly executed. Since I am sadly not an electronics nerd (aka can hack anything MacGuyver style) only an electronics fan, I may have missed some key details that are needed to make this project a success.
I started with a USB cable, with a typical male-connector on it, and a similar power-adapter to the one I lost. Now I cut wires and stripped the ends to get good ends to work with. USB uses 4 wires, the white and green are data in most cases, so I wanted the red and black ones for this. Red is positive and black is negative just like in any standard battery configuration.
I basically spliced the wire from the plug (cut off the old adapter) to the USB cable's appropriate ends and wrapped up the cable with electrical tape. It didn't really charge my drill at all. I am wondering if anyone out there has ideas on why. Using USB will provide 5V to whatever it is connected to, and my drill needs 6V to charge. Is the one volt difference enough to render this psuedo-solution completely ineffective? I imagined that it might just take much longer to charge, but to no avail.
Why else would this not have worked, is it a matter of polarity perhaps? Maybe I had it all wrong, maybe I needed much more voltage than I thought, or something else entirely? I guess this might have gone better if I learned more about electronics and knew voltages, amperage and other such ethereal phenomenon. I am admiteedly not the sharpest tool in the electric shed.
When you don't-it-yourself, or when you don't know enough about what you are doing, it can be much worse than the seemingly non-eventful conclusion, and you can be very hurt if you aren't careful. How would I rectify this problem, is there a way to salvage or rework this idea, using a USB connector to charge a drill? Let me know, this is your chance to prove your prowess on the subject.
Comments [4]







Reader Comments (Page 1 of 1)
8-22-2007 @ 3:42PM
Ryan Faerman said...
The method you use to charge the battery depends on what type of battery it is. If you just hook up a LI-ION battery to some voltage and amperage it could heat up and explode. Hookup a Lead-Acid batter for too long, and it leaks.
A USB device can only draw 500mA before it gets turned off for going over its alloted power. You'd be better off picking up a universal adapter from your local CrapShack or Wal-Mart.
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8-22-2007 @ 4:14PM
Zathrus said...
The issue probably isn't the voltage, but the amperage. 5V @0.5A means a whole 2.5W of power. Odds are it'll take several hours, or maybe even a day or two, to fully charge a cordless drill power pack from the trickle of juice that USB can supply.
Also, it's unclear which wires you spliced on the old adapter -- the one going to the wall, which are expecting AC, not DC? Ones after the transformer inside of the power supply? If so, before or after the charge control logic (which may be very deeply unhappy with the incoming voltage/amperage -- either not working at all if too low, or letting the magic smoke out if too high)? Bypassing the charge control entirely is also bad -- the battery pack is almost certainly NiCd (or possibly NiMh) and overcharging it will damage the pack, although not catastrophically like LiIon.
Of course, overcharging it doesn't seem to be much of a concern yet.
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8-22-2007 @ 8:15PM
sanman said...
Put the drill down and back away slowly... ;)
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8-22-2007 @ 8:30PM
Ryan Carter said...
@Sanman, so, how much is my wife paying you to say that?
It is amazing that despite the endless portrayal in movies and other popular media that we still don't understand that nearly everything we do without thinking ends in some sort of disaster, due to our own negligence or downright stupidity. We, ok, I will never learn.
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