Cordless Drill Battery Refurbishing?

[peace brainerd]

I don't know why it took me so long to come to diyaudio with this question. At first it seems off topic. But 90 percent of us probably own a cordless tool, there's a wealth of electronic know-how aboard, and 100 percent of us are into 'do it yourself'.

So... I'm looking at 120 plus dollars to replace the batteries for my 14.4 volt Milwaukee drill. (for this plus the purchase cost, I could have bought HOW MANY Menard's 18 volt drills at 28.95 and pretty much tossed them at the first sign of trouble?)

There are a few online shops that will refurbish, but after shipping, etc, the cost is still 75 percent of over-the-counter. Interestingly, PrimeCell.com claims to be able to improve the build of a battery like mine from 2.4 amp-hour NiCd to 3.0 amp-hour NiMH. Who knows? Anybody ever dealt with 'Batteries Plus' stores?

Anyway... is there a source for the individual NiCd/NiMH batteries that might enable me to order what I need and repair the thing myself? My battery comes apart easily with six screws (evidentally DeWalt's must be cracked and reepoxied) and the individual battery units within are connected by stiff spot-welded wire. That's the only real hurdle I can see - since I'm not going to be soldering the ends of these and they'll have to maintain solid contact under reasonable (ab)use.

Whew.... just explaining this is starting to convince me to just send em off for repair. My charger is an automatic 9.6 - 18 volt NiCd/NiMH
model, so I could easily upgrade to their "best" line.

Any thoughts?



Incidentally, while I'm here, an interesting side note. Makita has taken an interesting approach to taking advantage of Chinese industry. They didn't simply spin off a "stealth" brand for fear of weakening their name/reputation like most companies. They came out with a line of "Maktec" tools that are virtually identical to their main line. Same color - feels the same in the hand, etc. 100 percent made-in-China and marketed as comparable quality, same warranty, but with fewer features, bells, and whistles. They are cheaper enough to make them worth a look. Interesting approach. Wonder if it'll work.

[Stocker]

I think as long as the technician isn't 3/4 blind and neither hand is tied behind his back it shouldn't be too much hassle to refurbish a battery pack unless it's all plastic-welded together (I just took apart a cheapie and it was screwed together).

Google up anyplace that sells individual cells. Take pictures. Report back...

[DigitalJunkie]

Usually not very hard..
Be sure to keep,and re-use any thermal fuses,etc. that might be in the original battery pack..

Hit up google for the cells,there's a million places that sell them,just gotta find a good deal on some decent cells..

[AdamThorne]

I don't have any experience with high end tools like Milwaukee, but I have had a number of rechargable electric and electronic things. From razors to phones to computers. And a (cheap) drill. Eventually the batteries always die. Usually this results in a big PITA, as the manufacturer has often moved on to different models and form factors.

This has led me to conclude that one should never buy a rechargable thing when a wall-powered thing will do.

When my drill batteries died, I went out and bought a regular drill. Cost less than a cordless of equiv. quality (or rather, the corded drill I paid the same amount for is much nicer), and it's able to deal out WAY more torque. I'm never stuck with dead batteries. Since I don't do any work when the power is out, or at sites remote from the grid I have been very pleased with my purchase, and am glad I didn't go out to buy more batteries. Especially since my drill usage pattern is not conductive to having well-maintained batteries.

My suggestion is that you consider spending the money in stead on a corded drill. I dunno, maybe you need the cordlessness. I didn't. The Milwaukee is, I'm sure, pretty nice. You could probably recoup some money by selling it. Not the answer you were looking for maybe, but worth considering...

[Jason Hubbard]

The Milwaukee is a good tool and i'd refurbish the battery pack rather than buying a new one tool anytime.

After getting the battery pack open (quite often they are plastic welded, but even then it's not impossible if you're careful), measure the dimensions of a cell - you should find that it's a C size cell (at least in diameter), possibly it will have a shorter length (4/5th is common). Most electronic shops will stock these cells - try and get ready tagged cells, they are easier to solder together.

Use desolder braid or something flexible to connect the cells together - rigid connections sometimes fracture (a problem corrected by Milwaukee in later versions of their battery packs, identiifed i believe by grey battery release clips rather than the earlier black ones).

Good luck!

[AuroraB]

I don't know the price of the original B.pack you need, but a 10-pack of 3Ah NiMH's is appx 61$ at Digikey. Don't mind the spot weld thingie... a good solder job is actually better - I regularly make battery packs for large sounding rockets (!), and we actally prefer quality hand soldering over the spot weld.
You will need to make sure you get the riight size, of course.. ;-)

Just make sure you use good quality batteries - there are some cheap no-good ones out there.... If it is cost efficient - that's entirely up to you.

I've had several cheap, no-brand models, and I just can't describe the joy when the last one fell down the stairs!
Then I bought a Bosch..............

[peace brainerd]

Using de-soldering braid for connections is an excellent idea.
I am fully on your side where corded tools are concerned. The ONLY cordless tool I own is a drill. This is because I have an embarrassing wealth of excellent corded drills but I happen to have borrowed my brother's DeWalt cordless for a project ONCE. I was hopelessly hooked. After I got the Milwaukee I grab it 98 percent of the time even when I'm next to a plug. I would never, however, spring for anything else cordless.

The best deal out there seems to be Batteries Plus right now. Said over the phone that they would rebuild my 2.4mah battery with warranty for 41 dollars. Upgrade to NiCd or NiMH up to 3.0mah for 54 dollars.

I sent emails off to four separate cell distributors to see about ordering the 12 x 22mm x 42mm cells and will wait on the results. Most probably won't deal with such a small order. We'll see.

That Digi-Key price sounds like I might be better off just letting Batteries Plus handle things. Don't know what they use (panasonic, sanyo, etc) but they are warranteed.

Now if I could concretely decide between NiCd or NiMH for this tool I'd be doing well. What would be quite nice would be a "fanny pack" of cells with a short cord/plug that could be used for big tough projects so that the little packs wouldn't get abused so quickly.
Hmm, maybe I'll make one.

(leave it to an inveterate diy'er to put WAY too much thought into something like this!)

[karma]

i refurbished one of my drills some time back, my local hobby shop
had the cells i needed normally used for remote controls cars.
now that i think about it there lasting longer than the orginals did.
and there cells have the tabs already Attached for easy soldering.



cheers

[Ron E]

"NiCd's develop internal shorts, but when good they put out slightly more current than NiMh's." I heard this somewhere, but I think the real reason is that if they all sold NiMH's, they wouldn't make as much on replacement batteries.

I believe you can often get NiCd's to take a charge if you charge up a fair amount of capacitance to 100VDC and then put it across the terminals. The sudden jolt melts the internal short and it will take a charge again. Take a look at some of the electronics repair faq's and make sure you fully understand the dangers before you do this, though. I wouldn't want the idea to cause you any injury.

[peace brainerd]

Internal shorts would be great!! Would I have to wash them less often?

sorry... I've had a few beers. I'll check back tomorrow.