Tired of dead batteries in your cordless tools? me too! so let's hack away!!

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Picture of tired of dead batteries in your cordless tools? me too! so let's hack away!!
ok this is my 1st instructable so please be kind.
Are you like me when it comes to cordless tools? I get so frustrated with half finished projects and hours of wait time while those "convenient" cordless tools charge. so, i wanted to add wall power to them but, the key for me was to achieve this and not make a permanent mod to the tool itself,. now the real question is.. HOW result do i get that result? surprisingly it's really simple, minimal soldering required and again not a permanent modification to the tool. the best part is that i can change from tool to tool for flexibility, i can still use battery packs when an outlet isn't available and it cost me no money.  OH and it only took about 30 minutes. OK let's get hacking!!
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Step 1: Tools and supplies

1) cordless tool(s).  I had a 24v firestorm drill/ jig saw/ reciprocating saw combo i had rescued from someones curbside trash (YaY free!!)
2) suitable voltage converter w/ power cord (IE laptop charger or such), works best if it also is small enough to fit inside the old battery pack (this one was in with a bunch of electronics i rescued from a dumpster (YaY free again!! sensing a theme yet?) You could build your own if you have that skill, or a wall wart will work fine too, i didn't have a wall wart capable of the 24v needed for these tools.
3) 22-24 AWG wire 
4) soldering iron w/solder
5)   shrink tubes, sandpaper or small files, pliers, screwdrivers, a dremel is very handy, hot glue gun and glue (or if you're like me and don't have one...improvise) 
6) and MOST IMPORTANT....a little common sense

Step 2: Dismantle battery pack

Picture of dismantle battery pack
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simple, easy and we should all have the basic idea how and what to do here...if not, STOP now!! check the photos for a couple tips though,
warehouse325 months ago

i've collected a few battery powered tools over the years and some don't have the charger anymore...this is a great way to restore them! thanks

connie466 months ago
What do you do if you don't have the batterie pack?
carlos66ba1 year ago
Good plan! I have a question, though... I tried the same trick using a laptop power supply (19.5 V) to my 18 V Ryobi One tools. Alas, when the tool starts the current required is too high and then the power supply simply shuts down. I measured (using the batteries) currents well above 15 A when tools start and I do not know of any compact and inexpensive power supply capable of that. What was your experience?

I had the same experience with Ryobis. Not entierly sure what the issue was.

abadfart1 year ago
Thanks I'm going to do this for my ryobi set the saw just eats up the 18v battery's

I tried this with Ryobi and didn't have good results. Did you get it to work?

CobyUnger8 months ago

I tried this with a set of Ryobis and it resulted in a super slow low power tool. Do you have any suggestions?

ddwight11 months ago
You're a genius
sq_10_e1 year ago

Hey, I have that same tool combo, my dad gave it to me when he upgraded his set, and my batteries are ancient and don't hold a charge for long. Can you point me to a suitable voltage converter with power cord?

Do you think this would work?

zacker1 year ago
so if I use this? i can do this with my craftsman 19.2v drill?
schadduck (author) 1 year ago
thanks to everyone for your kind comments' I had some issues signing in lately so if I have missed sending a response to any questions I will try to get caught up. just to clear some stuff up: the batteries were removed and replaced with a converter, amps were checked and double checked then I had a friend check a 3rd time, same goes for watts and volts, a multimeter is your friend here. also for positive and negative pay close attention to how the batteries are connected before removing them, this one actually had it marked pretty clear but I did check with the multimeter as well just to be safe. oh and an update...I finally got the glue sticks for my glue gun, no more messy improv stuff there.
ibonneau1 year ago
is there a way to determine which one is the positive and which one is the negative ?

Thx for this project - exactly what I needed :)
best way to tell is to look on the battery, use a Multi/Volt Meter or a Test light
Celt1 year ago
P.S. , Goodwill always has awsome adapters and electronic parts for cheep. I'm sure I can find exactly what I need ther.
Celt1 year ago
I was so excited to finally see this project being done! I have an expensive drill and three dead batteries. Replacements were over 40 dollars each! I will post progress of the completed project when it is done'
This is very helpful. I had never thought this through. Thank you!
armstk1801 year ago
good job Man !
franco401 year ago
Hey schadduck....I saw your posting and it reminded me of the Instructable I put together this past January. Check it out if you get a chance.

I just want to warn you and your readers on a couple of things I found out when I did a similar hack.

First, for a high voltage cordless tool such as the one you used you need big enough power supply to overcome the startup current your motor draws, 15amps minimum for safe operation. I don't know the power supply you used, but for it to fit in the old battery housing I don't think you would be able to produce the amps you need to drive the tool with the trigger pegged from the get-go.

Secondly, your warning might exclude you from liability, but I'm no lawyer just a humble engineer. I'd advise you not to use a power supply recovered from the trash as it might have been there for good reason or it might be seriously undersized. Please, please, please I'm all for reuse and recycling, but replace it with something rated for the amps you will draw if you plan on using these tools for long periods. A switching power supply with a built in shut-off will only set you back $50 for a 24v 20 amp. You won't be able to fit it in the battery case, but its not a big deal to run an extension cord to it and keep it by the wall outlet.

Just my 2 cents.
schadduck (author) 1 year ago
to address XOIIO's concern about the batteries, there is no need to isolate them as there are no batteries/cells in the case with the converter. basically i used a "hollowed out" battery case to act as the enclosure for the converter.
schadduck (author) 1 year ago
i measured my power supply at 38v and the tools are 24v, i was afraid i'd end up burning the motors out or some other catastrophic type failure but it works perfectly. i think what is going on is the tool needs a slightly higher voltage when it first powers up then it levels off, might be the converter "senses" the draw and regulates the output. i suspect the power source you had was too close to the required voltage for the tool. i did measure a battery pack from another cordless and noticed it was in fact higher than the tools stated consumption. if you take the stated 24v of this tool times 1.5 it is 36v which is pretty close to what my source is measuring, it's possible that is where you need to be for yours. IE: 18v X 1.5 = 27v or something reasonably close might give you the power needed. I'm certainly no expert and maybe other here can correct my thinking or point you in the correct direction
You really need to be worried about the batteries, I'd add a double pole double throw switch to isolate them from the power supply, if you did not.
chaosrob1 year ago
Very good ible. I tried this 3 years ago with a laptop PS for an IBM, but it was a 'switching PS' and would not work. The current in-rush would cause it to reset, and all the drill would do is 'pulse'. I see your PS is using a transformer, and that is what I need to look for. Congrats.
Doug19651 year ago
put on some socks
I have been meaning to do this, excellent job!
schadduck (author) 1 year ago
ok please forgive the way i have to reply. for some reason i can't seem to do individual replys. so, here goes: for nlaspelotas; i can't see why not. you would have to use a wall wart though, couldn't fit a converter into the mouse. to rghoff and no1speshal thank you for the kind words and encouragement, i had thought about approaching black & decker with this idea and trying to sell it to them, then i thought..."don't they already get enough of our $$'s" so i posted it here for everyone to get it for
no1speshal1 year ago
Good job! I am always working with cordless tools and I will do this to one of my dead batteries. Thank you!
rghoff1 year ago
That's a cool mod! The manufacturers need to provide something like this as a backup to the batteries dying. Plus you can always go back and use a new battery. Great job...
I have a question, can I use this with a wireless mouse?
it KILLS you! (and your wallet)