Cord for Cordless DeWalt tools

[Guy Berthiaume]

I have a set of 18-volt cordless DeWalt power tools that I got about 3 years ago. Since I use them rather infrequently, I'm not getting the lifetime out of the very expensive batteries that I would like. The set originally had two batteries, but both have since quit working. I have one replacement battery now, and it seems to be less able to hold a charge as time goes on.

DeWalt apparently does not make an AC to DC converter that would be able to power these tools with a cord. This is unfortunate because it's a pain to have to stop work while the battery recharges. I presume they don't offer this product because it would eat into their very lucrative battery business... understandable.

Does anyone know if there is a third-party that makes a corded power attachment for cordless tools?

Thanks, Guy

[Andy]

I don't know about a third party, but Dewalt makes a product that would suit you very well. It's about $45, which would be less than the price of a new battery, and it will actually give you much better performance than your current setup. See:

(If the link doesn't work, search for Dewalt item # D21008K) I actually own one of these products (got mine for maybe $35 on eBay), and I've been very happy with it - highly recommended. Andy

[Leon]

Like Andy commented, a much stronger corded drill would be cheaper than an

18 volt adapter.

[WoodButcher]

The battery business *is* very profitable and the manufacturers have locked out 3rd parties by patenting the battery - drill interface/connection. This is why you don't find 3rd party batteries either. They can't stop you from getting your battery packs rebuilt, but by welding the cases together some manufacturers make it more difficult.

I know it ain't a Dewalt but Ryobi is the only one who I'm aware of who makes a corded 3/8" drill with a clutch. For infrequent use it may do ok.

[neillarson]

I also needed a new Dewalt battery, tho mine was a 14.4V. 89 bucks was the best i could find, or 50 for a used one on Ebay. Then I found a rebuilded. I got a new 2100Mh 14.4v battery core shipped to me for 39 bucks. I just have to put it in the old case and make 2 solder connections. If you can afford the time to ship him your old battery, he will do it for the same cost.

are is California.

[Guy Berthiaume]

The problem that I have is that I have a set of DeWalt tools: Hammer Drill, Jig Saw, Circular Saw, Reciprocating Saw, and Worklight.

It sounds like I am going to have to design my own converter. I can take a dead battery, remove the cells, and connect it to an 18 volt power supply. I was hoping someone had already done this, so I wouldn't have to think about it.

Oh well, this is a hobby for me so I might as well take the time...

Thanks for your responses. At least now I know what direction to go.

Guy

[WoodButcher]

Think about this before you spend time and $$ on this project. If a 115V drill pulls 6A, then your 18V drill will pull about 38A for the same power levels. This will take at least 6ga wire to connect your power supply to the drill. Do you want to deal with the weight and inflexibility of this cable?

An alternative would be to design the converter/power supply to fit into the battery case and run a regular power cord to the wall.

Art

[CW]

The problem in both cases is going to be the transformer. To handle amps like that, it is going to be WAY to big to fit in the tool and way to expensive to be practicle. With a transformer that big and the regulator to handle that power, I would be surprised if you could do it for less than $400.00 to $500.00.

[Chris Friesen]

For this sort of application you don't need a big linear-type supply. The motor doesn't really care about noisy power, so it would probably be possible to fit a switching supply into there.

However, one that can provide almost 40A at 18V isn't going to be common or cheap.

Chris

[patrick mitchel]

If yer close to a home depot, you can buy the ryobi packs, gut the cells from it (they are the same size) and build yer own packs. I've even seen replacement packs for no name drills at big lots (a US closeout retailer) that use the same size cells. Though they are of lesser capacity and quality than the brand named packs.... Pat

[Leuf]

The 38 amps came from assuming the motor was drawing equivalent to a 6 amp corded drill. A 6 amp is toward the beefy end of the corded spectrum. My milwaukee 1/2" is 5.5 and my ryobi 3/8" is 4.5 amps. So I think you're looking at less than 30 amps at 18V. I should think you'd want to know what the actual draw is for all of the tools you plan on using it with, and hopefully the supply has an overload protection so you don't blow it out.

-Leuf

[Leon]

And yet a 3.5 amp battery is all that is need to power the 18 volt drill. The 18 bolt drill does not pull very many amps at all. 18 volt drills motors so not deliver near the power of the corded 115 volt model drills. The 18 volt drill can deliver close to the same torque by gear reduction at the sacrifice of chuck RPM's.

[Leon]

With the assumption that the cells of the cheaper brands are of similar quality, go to Harbor Freight or Sears or Northern Tool and buy a $15.00 18 volt battery pack and use those cells.

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[N Hurst]

I did this with a B&D Firestorm 12V pack and swapped it into a spare DeWalt 12V pack with dead cells. I was a $10 closeout at Target, so it was worth the cost.

The resulting battery works well enough, I guess. In my opinion the $50-60 spent on a replacement XRP batery is worth the additional expense. The XRP battery runs more powerfully for a much longer time.

Honstly, I'd look into just sending your old batteries in to one of the online battery shops. One was linked here last week where they'll actually upgrade your batteries to Lithium Ion cells for a modest inprovement in cost.

So in my opinion, you're better off keeping your kit and saving yourself a lot of wasted time and money and just buy some replacement batteries. If you're interested in recycling and not buying new, look into getting your batteries refurbished at a local battery shop or look up that site mentioned here a week or so ago.

-Nathan

[bf]

I find it hard to believe that a cordless battery pulls 38 amps. If you take one apart, I doubt that they have 6 gauge wire inside. I'm certainly not an expert, but that seems fishy. (I doubt the battery pack can supply 38 amps )

[B A R R Y]

I don't.

I used be heavily into competitive radio control car racing. We tried to set the car up to completely drain a 2000 mAH Sub-C NiCd pack in 4 minutes + 1 lap (about 3-4 seconds). We used bus bars from cell to cell, and ultra flexible 12 ga. wire, as the wires were only a few inches long.

We tested packs @ 30-35 amp discharge rates using devices like this:

If the cells were matched well enough the pack would "dump", and totally die in the space of seconds.

[CW]

No, the batteries don't, but the motor very well could. Rechargeable can put out an amazing amount of current. No, you won't find 6 gauge wire inside. You won't find wire at all. You will find sheetmetal straps connecting the cells.

[Leon]

I have heard also, and it does make sense, that the OEM batteries at the Borgs are probably not too good to buy. As most wait to buy 2 replacements and then end up spending a few dollars more for a completely brand new set up the single replacement batteries tend to set on display for years. The shelf life tends to lessen and the batteries tend to not last as long. This happened to me with some Panasonic batteries several years ago.

Agreed, however can you charge a lithium battery in a NiCd or MiMd charger?

[Leon]

Some of my old 9.6 volt batteries had wires in combination to the thin metal strips, and IIRC a thin wire diode.

[Leon]

Yes however drills are not set up to drain batteries in 4 minutes. Many cordless drills will work hard for hours on end.