battery bank

After fully charging a battery and getting ready to fly, I quickly open the battery page for the aircraft. When looking at the battery cell indications the cells were not 100% full, but had one bar on the top missing. I've only charged these batteries a few times and am confused why they are...

https://www.amazon.co.uk/dp/B07B926KZ8/ref=cm_sw_r_cp_apa_i_eHvhBbJMTCDJ1 Smatree DP160 Battery Charging Station for DJI Mavic Air (Charge up to 5-8 Mavic Air Batteries) Has anyone bought one of these? They look really useful for travel or at home (not for airplanes, 158Wh)

Just took my Mavic for a flight using two batteries. Finished flying and brought my Mavic inside to charge the batteries. I placed my two batteries into the charging dock, as I usually do, and when I did so the light on the charging dock went red. And the green light closest to the power switch...

After fighting with the mavic car charger with its odd voltage requirements, I have found a solution that works if you want a true portable solution for charging your batteries. Good if you are in remote locations, hiking, if car 12 volt socket shuts off when ignition is off. First this power...