I am experimenting with the DS1307 and the Arduino, I had to find a way to connect a CR1212 battery.
I rummaged into my connectors box, and found nothing that could help. Then, eurêka! I had an illumination...
Step 1: You Will Need...
- one CR1212 3V battery
- two rows of a double row .100" regular "snap-off" headers
Step 2: Slide It Gently But Firmly
The terminals are snap-of dual .100" headers. I was out of wire-wrap headers, so I pushed (hard) to slide the plastic part about midway through the terminals so they fit perfectly in a breadboard, have the right width, and stick out enough to hold the battery somewhat securely.
Be careful with your fingers, these terminals can and will break your skin if you push hard enough!
Step 3: And Voila!
Be careful with the polarity. The part with the engraving is the +.
When using a breadboard, make sure your are not shorting the battery (the battery should be parallel to the contact lines).
On another line of thoughts, I added a small 1uF capacitor in parallel with the backup battery connectors on the chip (not pictured). It gives you enough time to change the battery without losing the time.