Franken-Saw (a.k.a. how to use a DeWalt battery with a Bosch reciprocating saw)

I discovered a Bosch 18v reciprocating saw sitting on top of someones trash can. It didn't have a battery, but that didn't deter me. I have several DeWalt 18v batteries for my drills and I knew there had to be a way to use them. So I brought it into my workshop and began playing.

I disassembled the saw and traced the wiring to figure out which terminal was positive and which was negative. Once I determined which was which, I ran some wire from the DeWalt battery to the saw terminals to make sure that it operated. It did. Now to make it usable.

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Step 2: Tools

Picture of Tools
Bench vise
Long-nose pliers
Wire strippers
Crimp tool
Small flat-blade screwdriver
Electrical tape

Step 3: Modify terminal connectors

The female disconnect terminal connectors must be modified to fit the saw and the battery. The terminals for the saw need to be flattened, and the terminals for the battery must be opened up.

I flattened the 2 terminals for the saw using a bench vise. Just put the connector in the vise and tighten until it's flattened.

The other 2 terminals were opened up using a small flat-blade screwdriver.They must be opened up just enough for a snug fit on the DeWalt battery terminal. If you open it up too much, use your pliers to adjust it to the right size.

Step 4: Prepare cable

Picture of Prepare cable
Cut your power cord to about 5 inches long. It doesn't have to be exact, you just want it long enough to easily connect the terminals and fold the excess into the battery compartment.

Separate the ends of the cable and strip back about 1/4".

Place the crimp-on connectors on the cable. Put the 2 flattened connectors on one end, and the opened connectors on the opposite end.

place the zip-tie about 1" down from the base of the flat blade connectors to keep tha cable from splitting.
Your 'ible highlights a frustrating need in the marketplace. That is, an interface that will allow battery A to be used with appliance B. Not every toolmaker has the best tool or "A' tool for a specific application. But who wants to have 4 different kinds of batteries with the attendant chargers? Either a universal adapter, or family of adapters would sell quite well I think.

Of course, a universal battery standard would be better. But, just like the phone companies were against phone number portability, the toolmakers will resist anything that makes it easier for someone to purchase from a competitor.
Hence, the need for adapters.
I totally agree with you burner. I have aquired a number of tools a La dumpster too, and have also let go some still good tools because the batteries cost more than it's worth. So why not challeng ourselves to make just such an adapter that looks respectable and works well too. first one to complete it gets a prize
I just came up with an idea but it might be too good to post here.
mikejs pfred22 years ago
I think I just had the same thought.
ironsmiter2 years ago
that's a great idea...
well, good idea.
um... Interesting idea.

Nono, Great idea, just a little "off" in execution".

"Let me ‘splain. No, there is too much. Let me sum up."

That's a great saw. I have one. Part of a set(c-saw, flashlight and drill in addition).

Even with the factory batteries though, after several years use, they get a bit loose in the battery department. you have a golden opportunity here, since you're going to a corded connector already. Use the full length of the cord, and keep the battery in a coat pocket, or tool belt! You have all the advantages of a battery operated saw(portable, no AC needed, etc.) but without the added weight of a few pounds of battery weighing down your tool while you hold it in awkward positions to do your cutting.

Now that I mention it... Maybe that dead battery and toasted charger I have from the second set, should become the foundation for a new remote-corded-battery setup!

GREAT idea! thanks.