Here is a quick tip if you are thinking of purchasing a DJI Crystal Sky and you own a DJI Mavic 2 Pro or Zoom. When you purchase a CrystalSky it comes with a charging hub and batteries. The 5.5-inch version comes with one battery, while the 7.8 version comes with 2 batteries. However, a charging brick is not included when you purchase either versions of the CrystalSky. When DJI first released the CrystalSky it was mainly designed to be used with a Phantom 4 series drone or the Inspire series and the charging bricks from either of those drones will charge the CrystalSky batteries. In addition, if you own a DJI Osmo the charger that comes with it can charge the CrystalSky. The problem is many now purchase the DJI CrystalSky to use with other consumer drones such as the DJI Spark, Mavic Air, and the new Mavic 2 Series and are now in need of obtaining a compatible charger. On the CrystalSky product page, DJI has a list of compatible chargers you can purchase but for the most part, I find them to be very large and bulky as they are designed to charge large drones and not to mention they are quite expensive.
However, if you already own a DJI Mavic 2 Pro, there is an adapter you can purchase on Amazon that allows you to charge the CrystalSky batteries with your Mavic 2 series charger. This is way more convenient than lugging around a large Phantom 4 charger when you will already have your Mavic charger with you. Not to mention the adapter cables come in at under $10 dollars. I have been testing this cable out for a few weeks now and it works very well. The added bonus is you can also use this adapter with your Mavic 2 car charger that DJI Sells. This allows you to charge your CrystalSky batteries while out on the go. You can watch my video review on this Mavic 2 charging cable for the DJI Crystal Sky.