Battery drill external battery pack

I wrote an article years ago for an automotive magazine that said to do just that - take your battery drill and remove the dead battery, add zip cord and clips and use with the car battery

No, but I have, on a couple of occasions, cracked open the original battery and replaced the cells inside.

That must have been at least 20 years ago. I just bought some 4200mAh NiMH ones. That is suspiciously high, though. Around 3000mAh is more common.

There's no point. Once the first cell dies, the rest are not far behind. Also, an automatic charger could get confused if the battery had a mix of fresh and old cells. In the long run, it's much better economy to replace all cells at the same time.

I've done that a couple of times and have had great results. Better than brand new!

I looked at doing that once. The original cells were spot-welded together with tabs of SS. How do you connect 8 individual Li-Ion cells?

You know, that would work fine, for 12 volt drills.

9.6 and even 7.2 volt drills will run a LONG time on 12 volt battery. A friend build a Zenith 701 using a 7.2 Makita on a 12 volt battery - and that's a LOT of holes.

works fine on lower voltage too - I was using a 4.5V drill, no problems - the back EMF builds rapidly

In my case it's only the lack of getting "a round toit" that keeps me from it. I tore apart a dead battery pack for my 12 volt Dewalt drill about a year ago, with that very plan in mind. I used to use that drill to tap maple trees and I could get about 50 taps per charge. That's drilling a 7/16" hole about 2 inches deep. The idea is to simply strap a garden tractor battery to my back as I tap the trees. I shouldn't have to go back to the trail to get a fresh battery all day.

I would use something more substantial than zip cord, though. IIRC 16 wire isn't good for much over 4 amps. Why waste ANY power?--- I'd use

12 Ga extension cord wire.

Pete Stanaitis

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Storm> Have you ever built a battery drill, using a dead

Question of where you want to spend your effort on that use - I tapped about 200 trees using a brace and bit - the old fashioned cordless drill. I've also driven a lot of screws with them, including quite a number when all the new-fangled drills in the area were waiting on the charger. I'd much rather tromp around carrying & powering the brace and bit than carry a heavy battery (or one of those gawd-awful gasoline drills some folks just love.)

I also have a 12V drill awaiting the car-battery conversion - just don't see using it for that job, considering.

Now, that sounds like a good device. And, good battery life.

As to AC power, I know 14 gage is rated 15 amps, so 16 should be 10 amps or so rated. DC? I really don't know.

Vehicle starting batteries don't like deep discharges. If you do 25 holes between recharges. Your battery will last a lot longer.

Ive got one like that I use camping and such. I also have a 100 amp deep discharge battery I can use with it. I helped a neighbor build a storage building kit last fall. He didnt believe it when I told him I could put the whole thing together on one charge.HeHe.

Jimmie

That's not fair!

(Fun, yes, but not fair...)

What's that Lassie? You say that Stormin Mormon fell down the old rec.crafts.metalworking mine and will die if we don't mount a rescue by Fri, 9 Apr 2010 10:46:55 -0400:

Yes I have. I had an older sears drill, and one of the battery packs died. After the autopsy, I soldered heavy zipcord to the contacts. A cigarette plug on the other end went into a AGM battery, 12v 6Ah.

Draws a lot of power, about 20A.

Many battery jumper packs have a 10A circuit breaker.

You might find that the AA cell packs won't handle that much current.

You buy cells that have solder tabs welded to them. Just cut the tabs to length and solder.

Yes I have. I had an older sears drill, and one of the battery packs died. After the autopsy, I soldered heavy zipcord to the contacts. A cigarette plug on the other end went into a AGM battery,

12v 6Ah.

CY: Now, that sounds good.

Draws a lot of power, about 20A.

CY: Did you measure it?

Many battery jumper packs have a 10A circuit breaker. CY: I can believe that.

You might find that the AA cell packs won't handle that much current.

CY: Well, that's very possible. I had not thought of that.

Yep, would work - but why? - you've bypassed the fundamental design objective of a "Cordless" drill. If you have to put up with cables all over the place, use a mains powered one. But I must admit, theres one glaring exception - using a modded one to raise and lower the stabilisers on your caravan/rv. Beats winding 4 of them by hand, cheap enuff so theres no major drama if it breaks/goes walkies. NiCads - here at any rate, they are too expensive to replace a pack with brand name cells. Too much, considering the cost of a new drill, usually with 2 batteries nowadays. (And salvage rights on the old ones

- )

And in a reply to your query re my post, I dont want the chuck, I wanted the motor and the control electronics to build a power feed for my mini-mill. Combining 2 net references - one guy used the cordless drill motor and slightly modified the speed controls, another person came up with a nifty coupling that could be easily engaged/disengaged.

Got the housing built, and the motor mounts as well, need to machine the drive coupling to the mill lead screw. No precision, just power feed and rapid traverse, so any slop isn't a problem....

Andrew VK3BFA

Andrew, would you share a link to the nifty coupler? I've seen some DIY power feeds, but I haven't noticed a coupler that's easy to dis/engage.

Thanks

The advantage is for example when you're replacing an electric socket. The next nearest one is 20 feet away, and you're going down the hall, changing sockets. Running a cord is a PIA, but a short cord to a battery pack is fine.

Thanks for the note on why removing a chuck.

I've had moments when I'm away from a power socket. But, a short cord to battery pack would be no big concern.