New ask about old topic-AC adapter for cordless

[install4you]

Greetings to all!

I’m a new forum member and I’d like to revisit a topic discussed here a couple of years back. First I’ll introduce myself. Of my 4 different and diverse careers, my current (career #’s 2 & 5) most applies to the interests of this site. I’m a professional installer of most decorative and functional accessories for homes and businesses with a core business of installing draperies, blinds, other window treatments, framed mirrors, art, etc. I’ll be glad to share what I know in the future upon request but for now if you want just a little more info check out my website at www.install4you.com (http://www.install4you.com/). If you have specific individual questions please email me.

I have read through an earlier discussion of AC adapters to directly power cordless tools as well as researched the subject quite a bit around the web. In spite of various issues and “why bothers” there are still some times I wish for a way to plug an adapter directly from my cordless tools into an AC power source. I use my 12V Dewalt drill all day every day. Some days I use all 7 of my 18V tools and I use at least one of the 18V almost every day. I have a voltage inverter so I can easily operate an AC charger in my van. When I’m working on a ½ day installation unusual circumstances can exhaust 8 battery charges in no time and the cool-down/recharge cycle just can’t keep up with my needs. Sometimes AC is readily available and sometimes I just hate to push my batteries that hard. With a van just packed full and heavy its not practical to always carry corded and cordless of all the same tools.

I would like to find or build an AC adapter for my 18V Dewalt tools. Dewalt makes one (or used to) for 24V tools, but not for 18V. I imagine this accessory would consist of a standard shell from a battery pack with a transformer and appropriate circuitry inside and a cord leading out of it to plug in to an AC source. In the course of my research I have identified a few technical issues. The transformer itself (110V AC to 18V DC) might just be too large to fit in a battery shell. The amperage output of the transformer would have to be many times the capacity of a charger, and I don’t know that figure yet. There’s a heat issue. I just learned that the regulation and conditioning of the output could be rather complicated. A battery puts out straight line DC current and a transformer alone can’t match that because of the nature of alternating current. To more closely match battery power the proposed adapter might need both a voltage regulator and rectifier to clean up the power variance. I just don’t know how forgiving the DC motors and circuits are in the tools. My imagination and tenacity far exceed my knowledge base.

So here are my questions to the forum:
1. Does anyone know where I can buy an AC adapter to directly power Dewalt 18V tools?
2. Does anyone know how to build or have experience with an AC adapter to directly power Dewalt 18V tools?
3. Does anyone know technical reasons to explain why I should abandon this idea?
4. Does anyone think there would be a market for AC adapters to directly power cordless tools? I might be crazy enough to consider contracting the manufacture of them and marketing them myself.

Sorry for writing a book here. Thanks in advance for help and advise.

install4you (aka Eddie)

[cactusman]

no disrespect here....

You are describing a "corded tool". Instead of the hassle of a wall wart AC adaptor, why not buy a cheap [Harbor Freight] orange 3/8" drill..around $17.00 on sale. Then buy a lightweight two wire extension cord and you have a drill with an AC adaptor. clever huh?

Now seriously, I understand your thought line here and how convenient it would be for a module to replace the battery and allow the tool to be plugged into an AC outlet. However, This actually defeats the "battery power tool concept"

I think Black and Decker or maybe Skill tried to market such a concept years ago.

I do have another option for you....take an older run down battery pack, gut it!
Then go to All Electronics, or some other well stocked electronic store [not radio shack]
and find a small wall wart. Make sure it has the voltage and amperage needed to run the tool.

You may have to surgically remove the wall wart outer plastic to install it into the now empty battery pack. Add a two wire cord of desired length and have at it.

-OR- buy a cheap 3/8" drill at Harbor Freight with a cord...typically $17.00 and use it when your batteries are pooped.


Cactus Man

[stuart_canada]

Skil made this concept and i thought it was a rather good idea when comparing price of spare batteries at the time, the charger and battery would be doing recharging while you plugged in to the charger. but now looking back i am glad i got in the big boy tools and have spare batteries. i have a corded drill when i need the power and cordless when i want it. no point in having a tool try and do both jobs, they never do one job well enough let alone two jobs that well

[install4you]

Thanks to both Cactus Man and stuart_canada for your responses. I can’t disagree with either of you. I just believe that the adapter described would provide one more level of flexibility and convenience. I carry so much weight and volume in my van it would be a great advantage for the same tools to operate with (theoretically) unlimited run time via cords as well as provide the critical convenience of cordless. It really comes down to a personal choice. Right now, because it appears this type of adapter doesn’t exist, it’s a choice I can’t make.

Concerning the responses, I don’t mind buying good tools, corded and cordless, and spare batteries. I depend on them to make my living. Even though much of what I do is routine and can be handled by a few tools, I make myself valuable to my regular customers by bringing a wide variety of abilities and capabilities to every installation. In terms of tools and equipment, about 60% of what I do can be accomplished with my tool belt, a cordless drill, and a ladder. Add a few specialty tools and a decent box of general tools and you get the next 30%. Having the tools and equipment for that last 10% often makes the difference in me getting the call and some other installer having that work. That last 10% is where the AC adapter comes in.

About the wall-wart (I love that term) adapters: in my experience, most wall-warts amperage output is measured in milliamps. My laptop computer power “brick” is rated for an output of 19 VDC / 6.3 amps. Most of my corded power tools, operating at 110VAC, use from 5 to 12 amps. Since amperage required goes up as voltage goes down, powerful 18VDC tools might need as much as 20 amps. I just don’t have those technical details yet.

If anyone has had success in building one of these adapters I would love to know. If anyone knows (or is) an electrical engineer who would be willing to discuss this, please contact me.

Thanks,
install4you

[install4you]

First, my apologies for bringing what seems like a Dewalt-only topic to a Ridgid site. As a total newbie to discussion boards I just didn't recognize that the site was primarily dedicated to Ridgid. I was (somewhat desperately) searching for information on my topic and the original thread discussing the adapter I wanted came up.

Next, in spite of all the advice (from multiple sources) against pursuing an AC adapter for cordless tools, no one has told me it's technically impossible and I've had a few people indicate they would love to have such a device. I hope to find a way to get/build one. I think the concept crosses brands and might be better than many people think.

Last, I can't find a serious forum group for Dewalt. If anyone knows of one please let me know. I'm also still looking for someone with the technical knowledge/expertise to say it can't be done (reasonable) or help with design ideas.

Many thanks,
install4you

[wbrooks]

Anything can be done but size and cost are prohibitive in this case.
Todays high power drills have motors that run in the range of 480 Watts at stall load
Power = Volts X Current so Current required = 480/ 18 (18V tool) = 26.7 amps then add in a 20% buffer, you need a power supply capable of around 32 amps at 18V
The next problem is that 18V is not a common output range, you can easily find up to 14.4 V in that power range and down to about 22V in that power range, so now you need a purpose build power supply or a modular Lambda supply (read $$$$) or the expense of a DC-DC converter either way you will be well over $200 cost at production quantities (over 10,000 units).

So the short answer is that it is possible but no one would pay for it.

[papadan]

Large capacity transformer coupled with large capacity rectifier and regulator= corded drill takes a lot less valuable truck space.:(

[BHD]

This is not an AC power adaptor, but I have heard of some people using a battery pack made of motorcycle batteries or the gel cells type batteries and either making a belt pack and wearing it or putting it in a tool type box and using a cord. for a lot of work in one location or for extended run applications. I think this was not that uncommon on the 14 volt and using a 12 volt battery pack,

I do not know if a car battery charger (expecily if it has a high charge setting as many of those have a higher voltage to drive the charging), and a pack of batteries like above in the shop or on site would make a "AC adapter and use a old battery to make the tool adaptor with,

[Woussko]

Large capacity transformer coupled with large capacity rectifier and regulator= corded drill takes a lot less valuable truck space.:( And, It cost much less too.:o

[Woussko]

You could use (3) 6 Volt sealed lead-acid batteries in series. To charge them you could use an automatic ready made 6 Volt charger and connect it to battery 1, then 2 and then 3, but that would sure be a PITA. The other choice would be to make up a custom design charger. If done in large production runs the each cost would be OK but to custom engineer and make up one or two would sure make corded tools the way to go.

At one time Milwaukee had 12 Volt tools where you used a battery pack and a short cord to connect the tool to it. It hooked on to a heavy duty work belt. Things got heavy fast but you did get nice long run time and it was each to swap the battery pack. They had a longer cord where you could use a 12 Volt deep cycle battery (trolling motor - small boat) and run all day. People would set the battery in a small wagon.

Anything can be made up, the the $$$ factor comes along.


As for making up a custom power supply to run them off AC power, it can be done, but WBrooks hit the nail in with one blow. The old $$$ factor comes in.

I think what would work is an AC-DC power supply designed for 24 Volt truck and large bus electrical systems but change the regulator to around 18 Volts. It should have a constant output rating of 25 Amps or more and a surge (few seconds) of 50 Amps. Such a power supply can be made up, but again the $$$ will make people back down quickly.

[Velosapien]

They have made such an item, but it was very short lived.

http://cgi.ebay.com/NEW-DeWalt-DW0247-24V-AC-DC-Converter-24-Volt_W0QQitemZ220220032238QQihZ012QQcategoryZ50393 QQssPageNameZWDVWQQrdZ1QQcmdZViewItem