This time I’ll show you how to make an adapter, which allow you to use lithium ion batteries at old NiCd or NiMH batteries powered cordless power tools.
How I did it - you can check by looking DIY video or you can follow up instructions bellow.
For this project you will need:
Covered polystyrene sheet
Old NiCd battery housing
Drill and bits
Sand papter 280 grit
Step 1: The Idea
One day I was looking at those two cordless power tools on my workbench, and just been thinking, that will be very nice to get rid of old, heavy and small capacity NiCd battery by replacing it with lithium battery pack from Bosch impact driver. From electric side it’s totally possible, because both power tools are operating at same voltage - 18V.
There’s need to make an adapter which will have same form and connectors like impact driver at one side, and at other side - flush surface. This surface will be glued at a top part of old NiCd battery housing.
I have a spare NiCd battery housing from previous build - so I’ll use it.
First - cut of unnecessary plastic parts to get flat surface.
Step 2: 3D Printed Adapter
The easiest way to make an adapter is to use 3D printer and just print it. I don’t have one, but I asked mine friend to help me, so that’s how it looks. For those who have possibility to use 3D printer, here is a link, where you could download project files:
Bosch battery model for 3D printing: http://www.thingiverse.com/thing:1815758
Step 3: Material
Any way, most of you don’t have 3D printer, so I’ll show another method. As main material I used
4 mm Iroplast SB board. This is some kind of polystyrene with covered both sheet surface. It’s lightweight and it’s very easy to work with it.
Step 4: Rough Adapter Shape
Here is what left after cutting and glueing sheet on sheet to get rough adapter shape.
Battery sits and holds very well.
Step 5: Connection Terminals
Next - I made battery connection terminals. I used spring clips from same NiCd battery. Cut two holes in adapter body and slide terminals in. Bend and with rotary tool cut them in proper size.
Step 6: In Progress With Terminals
Connected two power wires to positive and negative terminals. Added some glue in gaps between terminals and adapter body to secure them in place.
Cut additional layer to cover terminals and wires. With fast drying super glue, glued last sheet in place.
Step 7: Adapter Fixing Point
Made a hole in battery top part and used it as a template to mark and drill a hole in power tool body. In this hole will be screwed wood screw, which will hold an adapter in place. Also made a bigger hole in adapter body, which allow me to put and screw wood screw directly to power tool handle.
Step 8: Soldering and Glueing
Soldered power wires to old battery connector.
With two components epoxy glue, glued both parts in place. Sanded plastic surface to get stronger joint. Clamped and left to dry. Also added some glue to fix connector in place.
Step 9: Finishing
Glue dried, so it’s time for final check. Looks, that everything is ok.
Marked lithium battery out line and with utility knife shaped to final adapter form. Sprayed some black paint to get more aesthetic look.
Step 10: Finished Product
And here it is - finished product. Of course, this is not 3D printed adapter quality, but I think it came pretty nice and compact as possible too. Plus it weighs almost nothing.
Step 11: Fixing in Place and Conclusion
Connected adapter to power tool and with wood screw secured adapter in place.
And it works. With this adapter and lithium battery pack I’ll get a lot of advantages, like: fast battery charge, bigger battery capacity, state of charge indicator, reduced power tool weight. Plus I no need more to have few different battery chargers for different power tools batteries. Using idea this adapter, I could use only one charger and one type of batteries for all my cordless power tools, even for oldest.