Do you also like to photograph using speedlight? Including long photo sessions? But you don't like often have to change the batteries, and also you want the speedlight to recharge faster?
Then you need an external power battery pack. You can buy cheap one for about $20, but it will be of poor quality or you can buy better quality one, but the price will be from $130 and above.
Both of these options did not suit me, so I decided to do such a device by myself, using for its manufacture cheap (about $30 for all) modules. To assemble such a device, you must to have basic knowledge of electrical engineering and be able to use a soldering iron.
The assembled device in its characteristics turned out to be similar to those that are sold in stores at prices above $130. Charging time with this device after a flash(speedlite Yongnuo YN600EX-RT II) at full power is 0.7 seconds, after a flash at half power - instantly. In this guide I will describe step by step how this was done, including photos of modules with their descriptions and links to them in online stores.
The guide is in PDF format(so you will need Adobe Reader installed) and you can download it immediately after the payment.