New Cells for Dead Cordless Tools

[ChiScouter]

4 out of my 6 24v Dewalt batteries are in the crapper. Because they aren't very popular replacments are expensive. There was a guy on Ebay some time ago that was replacing the cells in batt packs when you sent them to him. He claimed his cells were superior to the oem stuff and I thought his prices were reasonable. I lost his contact info, so I am looking elsewhere. Im also thinking about replacing the cells myself if necessary. Any imput on where to send my batteries, or info on where to get replacment cells would be much appreciated.

[ImNotRight]

Open up a pack and check it out. My 18v packs look a lot like a bunch of C cells, which I could probably build out of high capacity r/c car batteries for a lot cheaper.. But I didn't directly compare them so..

[pmurf1]

There is also a guy on Ebay that sells a set of instructions how to repair/test them. It's not very much and he had good feedback when I looked at it a while ago. Try searching for cordless battery repair or Dewalt battery. The way he described it, you pull the cover and test each of the small batteries and resolder new ones onto the array. Didn't sound too hard, you could probably figure it out easily without instructions, but as I recall he gave you a source for the batteries too for cheap.

[PARANOID56]

Most likely those battiers are "Sub-C" batterys. just like the RC cars. but for good batterys you are going to look at spending about 60bucks for two packs.
Shane

[86turbodsl]

This is the secret to oem battery packs: It costs too much to tool a special battery, so you buy off the shelf standard Nicad or Nimh and repackage them in a shell. www.digikey.com carries reasonable rechargables in any standard size. I've redone laptop batteries that way too.

[Rockit]

Most battery suppliers can put new cells in battery packs. Most of the time you can do a performance upgrade for less than the price of an OEM pack.

[Kaiser Bill]

Is there any trick to opening up the OEM battery cases?
Most of them look like they are welded up or glued.
Is there any particular seam you should cut?
I'd like to open up some of my bad ones,but would hate to f@#k them up by cutting in the wrong place.
Bill

[ImNotRight]

Is there any trick to opening up the OEM battery cases?
Most of them look like they are welded up or glued.
Is there any particular seam you should cut?
I'd like to open up some of my bad ones,but would hate to f@#k them up by cutting in the wrong place.
Bill
The Dewalt 18V I have just has a few torx screws holding it together. Don't have any other battery setups lying around to check.

When ya get a dead one, just figure it out.. If ya mess it up beyond reapair, eh, well it was dead anyways. If not, great.

[helocat]

Home Dp is pushing a line of Ryobi 18v cordless tools where you buy the bats separately. $20 each 18v pack. I was looking at them thinking they would be good tear downs for re-celling my Dewalts.

Mark

[Eric]

There is nothing magical about these battery packs. OEM want to make money so they use the cheapest battery they can, but they are still good batteries. If you want to upgrade your batteries, just take the case apart, buy some replacement rechargable NiMH or NiCAD, solder them together, and put them back into the original case. I have done this a few times with great results. This is a lot cheaper than paying for OEM batteries or haveing someone else do it.

The only issue is you need a really hot soldering iron since the batteries soak up the heat so fast.

[jeeplord]

I stopped by a Batteries Plus, they wanted $40 per battery to rebuild them, I was looking at 3 so I just went and bought another drill for $140 and got 2 new batteries.

Dewalt has a higher end charger that can restore battery life through an 8 hour "repair cycle" something else to think about.

[tdavis]

Time for the Sunday Science Experiment.

I have a dead dewalt 18v pack..


First, the victim, a dead 18v Dewalt battery. I can find this locally in the $80 range.. Probably get it cheaper mail order.

http://www.pirate4x4.com/forum/attachment.php?attachmentid=156461&stc=1


Opening it up, and you'll find this:

http://www.pirate4x4.com/forum/attachment.php?attachmentid=156462&stc=1

Finally, there 15 each of these, wired all in series, which appear to be about 'C' cell in size. Doing the math, 15*1.25 = 18.75 volts.

http://www.pirate4x4.com/forum/attachment.php?attachmentid=156463&stc=1

The only markings on the cell are "JAPAN EB".

[tdavis]

Oh, and looking on flea-bay, you can get this pack for about $50-60 range (depends on how much they want to fleece for shipping).

You can get 20 c-cell batterys, nimh (not nicad) for about the same cost.

NiCd (nickle cadium) is known to have problems in a battery.

Found the batteries - it's known as sub-c size. you can get the packs rebuilt at http://www.voltmanbatteries.com for $35

[Kaiser Bill]

Those De Walt's look a lot easier to open than my Makitas.Mine look to be glued closed.
I guess I'll just flip a coin and choose a seam to cut.Like you said, I'm only out a battery thats already dead!
Thanks for all the info everybody
Bill

[jeepnmatt]

You can get 20 c-cell batterys, nimh (not nicad) for about the same cost.

NiCd (nickle cadium) is known to have problems in a battery.

Found the batteries - it's known as sub-c size. you can get the packs rebuilt at http://www.voltmanbatteries.com for $35

http://dkc3.digikey.com/PDF/T043/1286.pdf

after reading thru this from digikey, it looks like the NiMh batteries take a special charger. will the normal tool battery chargers work? i have 3 dead makita batteries and 1 dead craftsman battery...i might be experimenting soon!

[tdavis]

http://dkc3.digikey.com/PDF/T043/1286.pdf

after reading thru this from digikey, it looks like the NiMh batteries take a special charger. will the normal tool battery chargers work? i have 3 dead makita batteries and 1 dead craftsman battery...i might be experimenting soon!

That's what I have been wondering too..

The price of $35 to rebuild the pack by Voltman, with 1900mah NiCD batteries plus one way shipping IS VERY tempting. The pack will be stronger than factory batteries, plus that price is cheaper than any thing I could find.

The charger will probably NOT like NiMH batteries, since the charge profile is different.

[jeepnmatt]

i'm thinking i'll probably just send mine to Voltman. those prices are only a few $$ more than what i can get the individual cells for and they know what they are doing.

their FAQ page has some interesting info on NiCad vs. NiMh...what do you guys think about this?

thanks for the good info and links!
Matt

[TLCObsession]

They don't say whether they are putting in NiCads or NiMH for the price. EDIT - Ooops they do - price is for NiCads!

BTW Eric - instead of using a really hot soldering iron, get the cells with tabs already on them (they are welded).

I used to build MTB lights before there were commercial products.

Jim

[Eric]

BTW Eric - instead of using a really hot soldering iron, get the cells with tabs already on them (they are welded).
Jim

I would have, but most of the battery packs I have built were from FREE batteries or other people who wanted me to make them battery packs. The easiest way is like you say....get the batteries with the welded tabs.

[Kaiser Bill]

The FAQ page says that Voltman doesn't rebuild Makitas...they replace with new batts.
Their price isn't too bad tho.
edit:I just reread the FAQ:....They don't rebuild the Stick type 7.2,9.6,and 12v's and the recessed case 7.2 and 9.6v
Too bad those are the ones I have.14 :rolleyes:

[ChiScouter]

In my 12V panasonics I am most unhappy with the 3.5 ah NMH batteries as compared to the old 2 ah Nicads , they make the gun much heavier, and I see no performance increase. charging time is longer also. In the panasonic line you can charge Nicads in any charger, but you need a special charger for the NMH batteries.

I went to Batteries Plus today, appears to be a chain store. They want 75 bucks to replace the cells in my 24v, compared to 50 for voltman. He did say that that they have a special charger that runs the batteries through 3 charge/discharge cycles to try and bring back dead battery packs. He says that 75 percent of the time it brings the packs up to very good performance. They charge 5 bucks for the charging service. I think I will try that first.

[korda]

I went to Batteries Plus today, appears to be a chain store.
I had a 14.4 volt Craftsman battery rebuilt at one locally. I think the cost was around $35 and they said they used a better quality cell than Craftsman.

[jeepnmatt]

anyone have some updates or experiences from Voltman?

[DRM]

anyone have some updates or experiences from Voltman?

Ditto - My 18v DeWalt needs some re-juicing :p

[Adam F]

Just be very carefull when you are soldering your battery pack back together. If you use too much heat, you can damage the battery internally, or it could explode.