Has anyone tried this (cordless drill)

[jw]

I have a 12V cordless drill with a dead battery. The batteries cost more than the drill, so I wont be buying a replacement. Before I toss the drill in the trash, I was wondering if I could run a cord out of the place the battery is supposed to go, an connect it to a 12V car battery. Actually I dont see why this wont work, since the battery is the correct voltage, but I thought I'd ask to see if anyone has done this. I would think it would have a lot of power since the car battery has a lot more amps.

[RicodJour]

Search on YouTube or Instructables.

R

[Jim Elbrecht]

Just be careful when using it overhead that you don't tip the battery.

I think it would work-- but wonder if it is worth the effort- beyond the 'that's cool' factor.

Jim

[DerbyDad03]

Let's suppose it would work...are you planning on carrying the car battery around with you from job site to job site?

Besides, the balance of the drill would be terrible unless you compensated for the weight of the battery.

Might be a fun project, but a bit (no pun intended) inconvenient to actually use.

[HeyBub]

On my project list is the disassembly of the battery pack and the replacement of the cells with a (hefty) 12v transformer and suitable other parts to turn the drill into a corded drill.

Here's a suggestion I gleaned from somewhere:

• The NiCad batteries don't like to remain connected to the cheapo battery charger that comes with (say) Harbor Freight drills In fact, the instructions caution to not leave discharged batteries connected to the charger for more than seven hours.

• FIX: Open the charger. Wire a 30-ohm resistor and diode in series with the hot lead to the battery contacts. This turns the charger into a trickle-charger and you should not have to worry about the battery being connected to the charger for more than seven hours. It will take, however, much longer to refresh the battery.

To REALLY gussy-up your modification, you can rig a switch to bypass the installed resistor to return the charger to a (relatively) quick-charge device.

[hrhofmann]

Are one or more of the cells shorted, or is it just that they don't hold a charge? If one or more cells are shorted, you can put the battery across a low-resistance source and burn the short open. Tell us more.

[Twayne]

It'd make more sense and be a lot more portable to use a smaller motorcycle battery. Cheaper, too. Whatever you use, you'll want to figure out a fuse size and diode to use too, just to protect the battery. You don't want it exploding or smoking on you. Glue some lead weights insde the handle/emptied battery holder to replace the missing battery weight, or inside the empty battery case if that's what you use; probably a better feel to use the emptied battery case for the weights. Cover the battery terminals somehow so they can't be accidentally shorted together.

Better yet, buy another drill.

HTH,

Twayne`

[mkirsch1]

Take your used packs to the local Batteries PLUS store. They will replace the cells with newer better cells for a fraction of what a new pack will cost.

[Dbdblocker]

It will work fine, use a long cord with battery clips on the end. I use a bridge diode on a 15 vac transformer for my 14.5 volt cordless drill. Works well. Took the handle apart and wired it right in.

[bob haller]

You can do the power cord thing, my best friend did that then bought a new drill.

Primecell.com rebuilds 12 volt packs for 33 bucks, the cells are way better than when your drill was produced

12.0 Volts Replace NICD with high capacity upgrade $ 33.00

[clare]

It has been done MANY times - and it works. Even 7.2 and 9.6 volt drills work well on 12 volts - particularly if drilling small holes where you can use the speed. A friend built his entire Zenith CH701 airplane using a battery drill on the end of a cord.

[clare]

If the drill and battery are both 12 volt, the big battery won't give it any more power than a fresh drill battery - but it will continue to provide that full power a lot longer. The drill will only draw so much current at a given voltage.

[clare]

The balance is actually usually BETTER without the battery. A 15-25 foot cord works well - or about 10 foot if working at a bench.

[krw]

That's true to the first order but the internal resistance of the larger battery will almost always be lower.

[Larry Fishel]

Of course it would work, but unless the idea is to use it in the field, you could buy a more powerful corded drill for the price of the car battery...

To me, unless yo use a long cord (which mostly defeats the purpose), this sounds LESS convenient than a corded drill.

On the other hand, I could see putting a 15 foot cord with battery clips on it and throwing it in the trunk of the car for emergencies.

[Jim Yanik]

" [e-mail]" wrote in news: [e-mail]:

AND a given load.

it just means the motor will be able to burn itself out under too much load,unless the drill has thermal protection. Or you'll strip gears. Plus,you get more voltage drop over a cord than from direct battery pack contacts.I suppose you could use that Monster Cable..... :-)

There was one drill brand that did offer a coil-cord adapter to use their

12V drill on an external battery,Hitachi might be it.

lugging around a car battery to power a drill-driver is not the wisest or esaiest thing to do.

Just buy a 120VAC corded drill.

[Mark Lloyd]

Too many people make that mistake. That's current CAPACITY. The drill draws what current it needs. The only way to get excessive current flow is if there is a short circuit. For that reason, you need a fuse. You can get a fuse holder that becomes part of the cord.

[aemeijers]

And for the price of the bits to cobble all this up, he can go to HF and buy a Chinese drill with a cord that will work better.

Since the drill is in the 'nothing to lose' category, I'd open up the pack, and look on line for replacement cells. They aren't expensive, and usually only basic soldering skills are needed to swap them out. A glue gun and/or duct tape to close the pack back up, and there you are. Not as fancy as a pro-rebuilt pack, but a lot cheaper.

[clare]

The one case where a cord to a car battery is an advantage is when you need to do a LOT of drilling andyou have no mains power available - as in the case of my friend who built his entire airplane in a shed at his vacation cabin - which is totally off-grid. That 7.2 volt makita drilled several thousand roughly 1/8" holes in 6061T6 aluminum, running off a spare battery which he charged in the truck on his way up and back. - drill all weekend on one charge.

[Matt]

Good point. Many years ago, I used D NiCads to replace the worn out AA NiCads in an electronic flash unit. I carried them externally, hooking them up to the insides using lamp cord. Apparently the unit was designed to work assuming the higher resistance of the AA cells, and the circuit burned up pretty soon when I used the D cells. I was pretty surprised.

If he's lucky, the resistance of the cord would cancel out the lower resistance of the car battery.