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Rebuilding Batteries

61K views 45 replies 39 participants last post by  ScoutDad  
#1 · (Edited by Moderator)
Hey guys, I have two Dewalt 14.4 batteries that need to either be replaced or re-built. Does anyone here have experience with re-built batteries? are they worth it, or should I just send them to the recycle center and get fresh ones?... By the way, for those of you who do re-build where's a good place to send them?
 
#3 · (Edited by Moderator)
To be honest I have never heard of anyone rebuilding them. Tool suppliers such as Lowe's and Home Depot maintain recycling centers for returning these batteries. New ones cost $74 at Lowe's (I bought one last month). It would be difficult to get one rebuilt for this price.

But here is a link that I found http://www.primecell.com/

Hope it helps.
 
#4 ·
You might check with an Interstate Battery Shop, not people that just sell batteries. The local shop in Bloomington, IL rebuilt some for me for $25 a pop.
I looked into rebuilding my own some time back and found it expensive to buy the individual batteries for the pack. I talked to an engineer for the battery company (Quest) I buy my rechargeables, AAA and AA, and he said he had the same problem at home with a drill, I had a Ryobi drill , at the time, and he said it was cheaper to just buy a new drill. ;-)
 
#7 ·
I went looking myself and found the labourand materials was not feasible.
I had 4 dead Sears 15.6 batteries; I went on E-bay and bought 4 identical volt batteries made by
Sears for almost nothing.. ". . Well anyway I knew the battery cases had 4 screws holding the cases together. Sure enough the ones from the internet did not match the contacts. I simply opened them up and put the good batteries in my old matching cases.
What I have done with all my cordless battery chargers is plugged into standard wall plugs. I control the power going to them by a simple rotary power timing switch. I have the" timer" next to my bench and I simply crank the power to them for 45 minutes whemever I am in the shop This intermittent charging eliminated the problem of burned out batteries. I have a " steady steam of power" and I haven't lost a battery in over a year.
I have a Dewalt 9 volt that I replenished in the same way. I certainly have seen alot of Dewalt batteries on the internet. Good Luck.
 
#9 ·
I had two Milwaukee 18V batteries rebuilt by MTO Battery rebuilders. http://www.mtobattery.com/store/
I think they are better than original and I'm happy with them.
However, after figuring the cost of shipping and the rebuild, it's almost the same cost as buying new batteries.

On a side note, just after I had my two of my batteries rebuilt, Milwaukee had a recall on batteries and I got two new ones to replace my other two batteries. So, now I have four new batteries.
 
#10 ·
I don't have any experience with any of the re-builders but I looked into doing it myself a couple of years ago and decided that it wasn't cost effective. Believe it or not if you price 15 (for 18V) good quality cells it is only slightly cheaper than getting a new battery. Figure in shipping, cost of my time and lack of warranty and it was a non-starter.

If your going to stray from OEM batteries please do your homework. Some batteries are designed to preform like a Formula 1 engine. Some batteries are more like a small economy 4 cylinder engine. The high performance battery will generate more power but won't last as long. The economy battery may last for ever but good luck drilling hard maple with a 2" bit.

One other thing. NIMH batteries are not inherently better than NICAD. NIMH is a little lighter for the same capacity, which is why the auto industry is interested in them, but an 18V 2.4AH battery pack will deliver the same power (voltage) for the same amount of time (Amp-Hour) regardless of the chemistry.
 
#11 · (Edited by Moderator)
Estley,

I've done exactly what you a contemplating doing. Rebuilding a DeWalt 14.4 volt battery pack. Before I lay out the facts I'll give you the final answer so you can quit reading and move on:

It's not worth it.

Here are the facts for DeWalt 14.4 v drill battery packs:

- the battery packs are based on nicad battery technology.
- the packs are built up from series connected sub-c cells
- nicad batteries are 1.2 volts per cell as opposed to the typical 1.5 volts per cell for alkaline
- to get to 14.4 volts you need 12 cells (12Ă—1.2 = 14.4)

  • you notice pretty much all of the nicad battery pack voltages are some multiple of 1.2, like 7.2 (6Ă—1.2) 9.6 (8Ă—1.2) 12 (10Ă—1.2) 14.4 (12Ă—1.2) 18 (15Ă—1.2) and so on. That's because they're all built up from a series of 1.2 volt nicad cells

- nicad sub-c cells are around $2.50 - $5.00 USD

Sanyo Nicads
Powerstream Nicads

- you need 12 of them per battery pack so you are looking at $30 - $60 in raw nicad batteries per pack
- when you open up the battery pack you will notice the factory cells are resistance welded together (a good thing).
- you will also notice the factory packs the batteries in with near zero wasted space.

You probably dont have a resistance welder that will work to spot weld the tabs of one battery to the post of the other battery. Too bad, that means you are going to have to solder the tabs together and possibly have to use some jumper wire. This is bad because the connections are not as good and the soldered connections take up more physical space. You have a poorer solution that you have a hard time fitting back in the case.

But if you decide to keep going make sure you buy the batteries with tabs, you'll need the tabs, top and bottom, to solder together.

If you are determined you can make it work. It is possible to get the batteries soldered together in way that is reasonably sound and will eventually fit, with a little filing and pounding.

Hopefully you made sure the batteries bought are suitable to use with your factory dewalt charger with similar charging characteristics. That way you can just drop you newly rebuilt pack onto the factory charger, otherwise you'll need to find or build a new charger.

Oh, and don't forget, when you cracked the case you might have split the plastic, but even if you didn't you'll have to find a way to epoxy it all back together and not leave any bumps or changes in shape so it will still fit and lock into the tools handle.

And finally nicad batteries require controlled disposal, dont just throw the old ones in the garbage.

So, if you went through all that fun you can actually rebuild a tool battery pack. And it will work, and it will have performance similar to a factory pack. But unless you've got a secret stash of sub-c cells, the right tools, patience and general handy skills, you wont save much, or any, money, and you'll likely end up with a sub par result.

So I'll say again:

It's not worth it.
 
#14 ·
I'm a little Sheepish about it - but I buy Ryobi drills because they
work fine and the batteries are cheap and easy to get… as in
1/4 the price of other batteries.

I owned a nice Bosch drill that was nicer in terms of ergonomics
but I just couldn't stomach the ongoing maintenance costs
of "professional" brand batteries.

On rebuilding batteries:

I've read about it and apparently its commonly the case that only
a few cells are bad. if you can open the battery case and swap
out the bad cells then you don't have to replace them all.

You can sometimes bring a dead battery back by putting it in
the freezer. When you take it out and charge it up it works
again - can't say for how long. Batteries can sometimes be
rescued by freezing them and charging several times before they
burn out for good and need to be recycled or rebuilt.
 
#16 · (Edited by Moderator)
I haven't tried this yet, buy planning on it. I too have a dewalt 14.4 with one bad battery.
In the april 08 edition of FWW, there was a short article on rebuilt batteries. They tested 2 different rebuilt batteries one from http://primecell.com and http://voltmanbatteries.com '
They both were as good or better than new ones. the price with shipping included was $40 per battery. for a Dewalt this may be the way to go, seeing that their drills cost $150 plus and batteries are around $70.
I'm going to try it soon on my bad battery and will post something here when i do.
and chico, i'll take the 14.4 if you don't want it.
 
#17 ·
I've rebuilt quite a few batteries with just a soldering iron. The cells that are inside are sub-c or SC cells. Here is a really basic article outlining what is inside a power tool battery. http://toolbatt.com/anatomy.html if your thinking of rebuilding one. You need to be really careful not to heat up the cells to long as this can damage them. I like to hot glue all the cells together first also, this makes it much easier to work on. I don't rebuild them anymore though it is just as cheap to buy a good quality aftermarket one from someone like http://toolbatt.com
-Earl
 
#18 ·
I tried it quite a while ago on two early B&D cordless drills that did not use battery packs. I got the batteries from Batteries Plus. After all the work and cost they didn't last long at all so I won't be attempting that again.

From my experience with RC cars and their NiCad battery packs to get the best performance you want to have matched cells, the characteristics of each individual cell being the same. Buying 12 cells out of a bin does not get you matched cells even when they're the same make an model. I have to think that the manufactures do this matching to some extent to get a decent product.

I too use DeWalt 14.4's, DeWalt sells a two-pack, usually in the $109-$119 range, I pick a couple up packs when they're on sale for $99. That brings them down to $50 a pop, right around what you spend on batteries alone to rebuild them.
 
#19 ·
i think i can add a little to the discussion. i love to tinker. in fact i do more "fixit" than straight woodwork.

that little booklet on ebay for 7 bucks is not a rip-off. i bought it last yr. its not very good for fixing dead

batteries but it had some good over view info. on how to care for you batteries. and explains difference in

fair detail nicad and nimh lith, and one or two others. i forget now but one is real sensitive to cold and the

other sensitive to draining past 90%. as fare as fixing dead ones its a hasle, you need 2 or 3 strong fully

car batteries. in sequence. ie you have to take the battery out of 2-3 vehicles unless you have several sitting around the shop.
i tried straping 6 9volt batteries and just wasted 6 9 volts., you can also "shock the cell supply l;arge charge to the 1-2 individual dead cells. watch you dont get burned and wear full eye protection b/c the sparks
are nasty, and possiblity that cell will explode.
in general not worth it but i like to tinker.
decide which tool you want and stick with it, buy one that uses same battery. i use ryobi 18volt

but for the guy with more bucks go with the rigid b/c free life time batteries. and although i love ryobi but
ridgid 24 volt will kick its ass.
the sawsaw and circle saw kill batteries fast.
i have like 10 drills 6 corded and 4 cordless 2 drill and 2 impact i dont like to change bits so i commonly use 4 drills all the time.
i have 10 batteries and number them so i always use and charge in seq. never take them down past 80%
never leave them in the cold for any extended period ie the truck or garage.

and try not to drop off the ladder ive lost a few this way. as i do alot of roof and gutter work.
 
#20 ·
I've junked quite a few batts dropping them off of ladders too. They don't seem to like that!

Someone mentioned earlier about matching cells and that is absolutely true. If you don't match the cells they wont hold a charge for very long because the smart charger will stop charging when the first cell reaches capacity leaving the others only partialy charged.

-Earl
 
#21 ·
I've rebuilt a couple 18v ryobi battery packs and seen much better power and life out of them than brand new ones. Its not that hard if you are confident with a soldering gun and a multimeter. It costs about $35 in batteries and tabs for me to do a ryobi which is worth it compared to $50 for a weaker stock battery. If a bunch of people want to see my process i could probably put a walkthrough together. I get all my batteries from all-batteries.com.

I have also done a bosch battery for my neighbor, it was more difficult because of how the connectors are setup. i haven't heard back from him on performance yet.
 
#23 ·
I have taken 14.4 volt dewalt batteries for several years to get rebuilt, they use 2000mah cells in your battery case that is screwed together, they have a one year warranty and run about $42.00 each. They test them prior to being rebuilt to make sure they are actually bad. They also check our chargers for proper output. Wholesale Batteries Inc. in Kansas City, Kansas. 800-886-8658. I will be taking 8 batteries next week for an overhaul but wont have any freight cost involved as they are local to me.
We have over 12 drills and 6 impact drivers so by the $$$ it works for us.
I just dont want Dewalt to profit from new battery priced at over $70.00 plus tax and freight.
 
#24 ·
I've read a couple of articles on the rebuilding issue. Some are favorable some aren't.
I have 3, 14.4 v Dewalt drills, two are now junk-bad chuck on one, smoked the other. I was buying Dewalts because it was cheaper to buy the drill and two batteries than to buy 2 batteries to replace the ones that were bad. I have replaced these drills with other brands and when the last one croaks,I will replace it with something else…why…because their damn batteries are 75.00 a piece and frankly aren't any better than anyone elses. Dewalt needs to get a clue.
 
#25 ·
We have some information on rebuilding these batteries, and we also have replacement batteries for DeWALT and many other brands so take your pick lol. www.eReplacementParts.com - "Sure some of you have heard of us ;)"