October 6, 2013

Project: Home Brew 9 Volt Battery Clip

The Eveready company introduced the 9v battery type in 1956.  The familiar 9v battery utilizes a snap or clip to connect to its terminals.  Home brewers, DIY enthusiasts, makers, and kit builders all routinely use 9v batteries or battery-packs that are equipped with 9v terminals to power their projects.  All these battery powered projects require 9v battery clips to attach the battery to the circuit.

Commercial 9v battery clips are of course readily available.  The commercial 9v battery clips are rather pricey ($2.69/each at a local electronics retailer) and lack somewhat in quality.
Why buy an overpriced and inferior component when a superior version can be fabricated for FREE from readily available recycled components?  Here is how we make our own 9v battery clips using parts recycled from dead 9v batteries.

9v Battery

Tools and parts used
  • A dead 9v battery
  • Needle nose pliers
  • Soldering iron
  • Electronic solder flux
  • Electronic solder
  • Hot glue gun and glue stick
Step 1: Open 9v battery case
There is a crimped seam that runs the length of the 9v battery case.  Using a pair of needle nose pliers, carefully open the 9v battery case starting at the bottom of the case at the seam.  It takes a little practice, patience, and hand strength to complete the operation.  Be sure not to damage the six LR61 size cells cells inside.  Haven't you always wondered what was inside a 9v battery?  Now you know.
9v Battery Case Opened At Seam
Step 2: Remove top and bottom from the 9v battery
Complete remove the cover once the case seam has been opened the full length of the battery.  The top of the battery is soldered / welded to two leads.  Break the welds by gently pulling the top away from the battery.  The bottom falls away from the battery on its own.  Keep the top and bottom.  They will be used to make the battery clip.  Properly recycle the remaining battery cells and case.
9v battery top and bottom removed from recycled 9v battery
Step 3: Solder leads to the battery top
We apply a thin coat of flux to the battery top inside metal.  The flux cleans the metal and helps the solder to flow and form good solder joints.  The red lead goes to the positive contact.  The black lead goes to the negative contact (the smaller circular contact on the clip).  The clip will be wired so that when connected to a 9v battery the positive wire is connected to the positive terminal.  Carefully solder the leads assuring good quality solder joints.
Red and black leads soldered to inside of 9v battery top
Step 4: Use hot-glue to affix the battery bottom over the soldered leads
The final step is to seal the battery clip using hot-glue and the 9v battery bottom.  Once the glue is dry, use a sharp knife to carefully trim the excess glue.

Step 5: Test your new clip
The purpose of this test is to both confirm you have correctly wired the leads to the clip and the clip is conducting power from a battery.  Connect the battery clip to a good 9v battery.  Connect your volt meter across the battery clip terminals by connecting the positive meter lead to the red wire and negative meter lead to the black wire.  If your meter shows approximately 9v then you have successfully fabricated a 9v battery clip.
Voila!  The home-brew 9 volt battery clip is complete in four easy steps.  Below is a photo comparing a commercial clip (left) with our home-brew version (right).  The home-brew clip has a much more durable look and feel.  Another obvious difference is the quality of the lead wires.  For this project, we used wire we recycled from a dead computer power supply which is heavier gauge and more durable.

Flimsy $2.69 Commercial 9v Clip on Left versus $0.00 cost home-brew 9v Clip on Right
We make several of these at a time to keep on-hand for future projects.
So why build when you can buy?
  • This is a fun and easy project.
  • This project can save you money (savings $2.69/clip).
  • This project would make an excellent group activity such as a boy scout troop electronic night.
  • Great way to make a 9v clip if ever in a tight spot (ala McGiver or repairing equipment during a disaster or emergency).
  • The quality of the end result is superior in several ways to the commercial off the shelf 9v clip.
Good DX and 73, NJ2X

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