I am looking for a way to efficiently charge a Mavik Pro drone battery in the field multiple times. I plan to take mine ‘hunting’ with me so I can get some really good aerial footage of sambar deer. Obviously I will not be using it to help me kill a deer.
Clearly I will need a substantial solar panel as the drone battery has Capacity: 3830 mAh Voltage: 11.4V Energy: 43.6 Wh Net Weight (240 g). I will have to charge a power bank type battery which has a capacity over 12 volts then connect a female cigarette lighter socket to it then utilise a cigarette lighter charger to charge the Mavik battery.
I am looking at these Xionel products. They all only produce 5 volts so that the battery I use as a power bank has to be able to be charged with USB power:
5 Volt 4.5 Watt Rollable US$85.40
700 x 290 x 16mm 21 watts 2 x USB 3.5 amp @ 5 volts4 folds 570 US$41.61 570 g
875 x 290 x 16 x 28 watts x 3 USB x 4.8 amp x 5 volts 5 folds US$ 51.93 Feb 2019 700g
850 x 265 x 16mm 24 watts x 3 USB 5 folds 4 amps @ 5 volts 620 grams $50.36 *
815 x 255 x 16mm 16 watts 2 USB 4 folds 2.6 amps @ 5 volts 800 grams $41.48
520x 290x 16mm X 15 watts 2 USB 3 folds 3 2.5 amps @ 5 volts 390 grams $33.28
The 24 watt panel (max 4 amps at 5 volts) seems to suit my purpose best as it should attach to my pack without protruding. Theoretically it should be able to charge a drone battery in a little over 2 hours. Accordingly I have purchased one. The individual panels are flexible, so the unit is very robust and will stand up to field conditions. It even charges my phone in a light rain so it will no doubt do the job on a bright day!
There is a kind of power bank which takes 18650 batteries (Panasonic are 3400 mAh). One that I am looking at will take 8 of these cells US$9.90. It can charge with USB current and discharge at 12 volts and 1.5 amps.
This may be enough to charge a Mavik Pro battery. If it is not I will just get a smaller charger, say a four cell such as this and I will have to make up a battery pack I can put them in (in series) which can output 4 batteries (14.8 volts) and up to several amps. I will wire a female cigarette lighter fitting to it and use a cheap car charger to charge the drone batteries.
A pack of four fully charged 18650 batteries should top up two Mavik Pro batteries. Obviously you never fly the drone in the wilds until the battery is flat. In decent weather i should be able to charge 8 batteries in a day fairly easily giving me four flights per day after the first day when there can obviously be more.
See Also: Drone Hunting