Super Battery Pack Hand Tools




Introduction: Super Battery Pack Hand Tools

As with most Battery pack tools, they are great when they are new, then the battery goes to crap and you have to buy a new one. And these battery packs are expensive and generally proprietary so each tool manufacturer needs a different battery type. The batteries also have a short life span and end up in the land fill. I have a couple ways to service these tools making your battery costs very low and the battery tools much more versatile. Not only is this a GREEN project, but it also keeps GREEN in your wallet.

The best parts of this are,
-The dead packs are modified, not the tool, so I can pop out My Modified pack and put in a regular battery if I need to get to a tight area where the cabled battery would be tough to work with.
-This battery has a much higher amperage than the standard battery packs. I find it lasts more than 5 times longer than the standard packs on a single charge.
- The actual life of this battery is longer than the regular battery packs.
-Cheaper and universal. One battery, several tools.


Always work safely with safety eyeglasses and gloves when working with these packs. A slip of a tool while prying could hurt you.

Step 2:

I took an old battery pack and opened it up. This one happened to be a 12Volt and it had screws holding it together. It was easy to open. Some packs are glued together and are much trickier to open, but it is still doable. There is some 2 sided tape usually holding the batteries into the bottom of the tray. Just pry them out. Basically we are removing the old dead batteries from the pack and replacing it with a cable that runs to an external standard GelCell Battery.

Step 3:

Now remove the wires connecting the batteries to the connector prongs. This prong assembly will be reused as well as the battery case. Becareful to not break or bend these connectors. They should slide out so you can resolder the new cable to it.

Step 4: Check Polarity

The polarity is usually marked on the top, but if not then it can be resolved later. The Connector you removed from inside will line up with these markings showing you where to connect your wires. Most of the tools will only use "+" and "-" for connections. The other connections are used for recarging of the old pack, which we will not use.

Step 5: Soldering the Wire

I found some old heavy gauge stranded lamp cord. I cut mine about 4 feet to have some extra room to move. But you can make yours as long or short as you wish.
The batteries will sometimes have 3 or 4 connectors on them, Try to find which pair work as the "+" & "-" terminals. There can be markings, or you may have to use electronic fundamental reasoning to figure it out. You can try to use temporary jumper clips to figure it out by hooking to a battery and to the tool terminals, trying different configurations until you get it right. Solder the cord to the two connectors that you determine are correct. Then I hot glue the cord to work as a stress relief if pulled.

Step 6: Insert the Connectors Back Into the Case

Once you are sure you connected to the proper terminals, put the connector in the case. I secure the connector in place with hot glue. Fill the end up good with glue. This will stop any movement of the connector inside the case. So you shoould end up with the connectors back in their original location with your new cable soldered to them.

Step 7:

I drilled a hole in the bottom to pass the cord through. I also tied a knot in the cable so it works as a stress relief in the bottom of the case, so that if the cable gets pulled hard, it wont tear at the connector you just soldered. You can put the hole in the bottom back end, for the cable to exit out of, as some tools stand up on the battery pack and my positioning will prevent this. I personally don't stand my tools up because they easily fall and break.

Step 8: Finished

Here I have two tools running off the same battery. Here is my 12 Volt Drill Adapter, and my Makita impact driver running off the same 12Volt battery.
For any tool guru, you may say "Hey that Makita impact tool is a 9.6Volt". I say, yes it is, and I use it with direct 12 volts and it works better than when new, and I have driven MANY MANY MANY screws with it, so I haven't found it to burn out. But if you are concerned, you can add in a High Wattage resistor in-line to lower the voltage. Or get fancy and build a regulator circuit that plugs onto the battery giving you several voltages to power different voltage tools.
The battery can be purchased from surplus stores for less than $10. And it gets charged with a standard car charger. These are regular no spill gel cells used in many different applications.

Step 9: Battery Belt

I also made a Belt strap harness that holds the battery so I can walk around with the tool in hand. This was a holster that holds those "Barcode Guns" you see people doing inventory with. It lets the battery slip right in and clips closed so it wont fall out. The battery wont leak so there is no possibility of spillage. It is not back holding it on your hip, but seems to be best located at the back like a fanny pack. Hope this is clear enough. Once you perform one, you will see how easy it really is, and if you are working with a dead pack, it will cost you nothing to try to save yourself lots of green.



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    17 Discussions

    Nice instructable! Just an idea for organizing your cord. I also hate getting tangled up in cords, if you have an old shop light that automatically retracts the cord with a quick tug on the cord you could repurpose this and use it as the cord between the battery pack and the tool. This way you could easily retract the cord when you are moving around. The ones that have the ball stop on the cord would also allow you to set a cord length. You could incorporate this into a floor box or a backpack to keep the portability. If you have an old canister vaccum cleaner they also had cord retractors. Just a thought I had after reading through the comments. Great Job on the instructable!!!!

    I tried this with a 12 volt 7amp battery and it did not give me the needed power.  what 12 volt battery are you using?

    Thanks I'm going to do this with one of my old dewalt raido's and hard wire it into my truck. probley need some kind of a fuse though. I love this web site!

    I have a 19.2 volt, where can I get a battery and how do you recharge it?

    3 replies

    With any of the tools that are 14.4 volts or higher, it will take a little bit more power to work properly. You would have to use 2 - 12 volt batteries and wire them in SERIES to give you 24 volts. to do this, just connect the (+) terminal on one battery to the (-) terminal of the other. Then fasten the two batteries together so they stay as one unit. I have used HOT GLUE to glue these battery types together and it is very effective. Then use the remaining (+) & (-) terminal to connect to the tool. This makes a battery that is 2x as heavy so it wouldn't be suitable for on a belt, unless you are comfortable with that weight. But it would still be good for a remote battery pack for your 19.2 tool. To charge this, you would have to charge them with your car battery charger individually, OR you can use alligator clips and put the two batteries in parallel during charge then switch it back to series wired during use. Sounds like a PITA but the length of time you get use out of one charge is so long that it is well worth it.

    ok so to recap I can wire to two batteries in series, use a quick connect to plug into drill and use same quick connect to connect to charger and charge in series?

    No. When you use it with the drill the two batteries have to be in series. THis makes the battery output to be 24 volts. But during the charging, you have to either charge the two batteries individually, OR rewire them into parallel> charge them> then swap back to series to use in the drill. In Parallel the two batteries are 12volt output and can be charge with a 12 volt charger. When they are wired in series, they have 24volt output, and can't be charged with a 12volt charger in this configuration, so you have to change it to Parallel.

    This is a great idea which I will do when I finally kill my battery packs. Since I often end up feeling like a contortionist in some of the tight spaces I have to work in, I'm going to put connectors on each end of the cord and figure out how to run it inside my clothes, strapped to my body or my clothing so that there's just enough cord coming out of my sleeves to let me use the tool with either hand. With a connector at the battery, I could put that aside while doing other tasks. I'd quickly go haywire it if I had to constantly stop to de-tangle or free up the cord in some tiny attic space or such. It's AWESOME that the gel cells are SOOOOO much cheaper than new batt packs! Thanks for that piece of the puzzle! Waytagoman, peace!

    1 reply

    I am glad people are actually enjoying this idea. Thanks for the positive comments.

    Cool... Hope the heater belt i did for the "Keeping Warm" contest was some inspiration. The lead acid is a bit heavier but if you have it in a belt or sling you should get MUCH longer run times out of it than the tool battery pack variety with not much inconvenience. If you are holding the tool above your head it should be a lot lighter now without the battery. I like it....

    1 reply

    Yes in fact the tool is much lighter. And the battery lasts for a couple days of good use before any charging is needed. Thanks

    He Dismantled the cordless drill to expose the leads that connect directly to the drill's motor. He then took these leads and connected them to the terminals of a 12v7 Battery. I hear there's a company making 12v7 batt's with lithium ion cells - really really light.

    thanks. that what i thought he was doing, but he really doesn't say much about the new battery. only at the beginning where he says it has higher amperage, longer life, etc. than the original pack

    You should show the belt strap harness, it keeps the thing truly portable. L