Iv been looking for a powerbank for my Macbook Pro for years. I managed to find one years ago at the price of $300, too much.
I recently purchased a powerbank from ebay and noticed it has a 15 volt option, considering the Macbook chargers are 16.5 volts it should have enough grunt to charge it.
The only component I ordered was the custom Apple cable. Here is the shopping list.
Ok, lets get started with the project. This project can be completed by a beginner, its not complex at all. You just need to ensure its completed correctly as it may cause damage to your Macbook is connected incorrectly.
So i found a Coaxial power cable in my garage, this is the cable connected to the powerbank. We need to fuse this cable with the custom Apple charge cable.
Once we connect the two, we must ensure we seal them correctly using some shrink seal.
I finished and connected it to my Macbook Air 11″, worked straight away. You must ensure that positive and negative is connected correctly. This is achieved by using a multimetre.
When you have completed the project before connecting to your laptop, using a multimeter compare the created cable with the power adapter. You should achieve readings like this.
If your happy with the results then you can connect it to your laptop, you should see the green light which will then turn to orange indicating that its charging.
Im really happy with it. I did a test of it charging capabilities. I charged the powerbank 100% and then connected it to my Macbook Air which had 15% charge. It charged it to 48%. Its probably around an extra hour of operation on the Air. Enjoy!