External batteries for our Apple notebooks aren’t cheap, but they’re hugely worthwhile if you’re frequently on the road with little access to a power outlet. But before you shell out $250 for a ready-made solution, why not make your own for less than $60?
Evan Rodgers over at The Verge has put together this 8-minute clip that takes you through the process of creating your own external battery for a 13-inch MacBook Pro, or a MacBook Air. All you need is a willingness to “get down and dirty with a soldering iron,” and the following:
- 2x 12v CCTV Battery
- 3rd party MacBook car charger
- Soldering Iron
- Flux (optional)
- Heat Shrink Tubing
- 5x Blocking Diode
Then all you have to do is follow the steps in Evan’s video to put this hack together.
You may be wondering why you need two CCTV batteries when Evan uses only one in his video, but he explains why this is best:
In the video I only use one CCTV battery, which does work, but because of voltage droop on the battery the car charger will power off after about half of the battery is depleted. This is actually a good thing, since it prevents strain on the voltage regulator which, if this fail safe were not present, could overheat the regulator. To remedy this, attaching two CCTV batteries in parallel with a diode between each battery will allow for a much higher current draw before the voltage droop takes effect. The blocking diodes prevents current from traveling back into the battery. This could happen if you were to use one charged battery and one depleted battery.
It’s also worth taking a look at Evan’s guide over at The Verge for a more detailed look at how this hack works. And if you do decide to try it yourself, let us know how you get on.