Did some testing on charging the Spark battery (capacity approximately 17Wh meaning 13,6Wh needs to be charged when battery is at 20% before charging).
First, charging with QC3 enabled charger (Aukey):

Charging at 12,4V with 1,41A meaning a rate of 17,5Wh. Battery full in less then an hour.
Secondly, charged with a high quality charger without QC technology:

Charging at 5,26V with 2,07A meaning a rate of 10,9Wh. Huge difference with previous situation. Minimum 1h30 to charge the battery.
Third situation, charge with MI powerbank with QC technology:

Charging at 11,9V with 1,62A meaning a rate of 19,3Wh. Again, full in less then an hour.

I know this is a theoretical approach as charging current is decreasing when the battery comes to fully charged but at least you can see that battery can be charged in different ways.
Hope this helps.

Great thread, thanks. What type of meter is that and where can one get one? Below are figures I tried with phone charger.
Charger Stats for Samsung Wall Adaptive Fast Charger.
9 volts at 1.67 amps
5 volts at 2 amp.
Charger temp was 114 F, and the top of spark was 98 f. Battery itslef never even got warm.
On the surface this appears to be a viable way to charge flight batteries. Question is, is it a good idea?

stuka75 Posted at 2018-5-9 05:30
Great thread, thanks. What type of meter is that and where can one get one? Below are figures I tried with phone charger.
Charger Stats for Samsung Wall Adaptive Fast Charger.
9 volts at 1.67 amps

Meter bought at Amazon: https://www.amazon.de/gp/product ... 0?ie=UTF8&psc=1

Seems like a little too much science around charging the Spark batteries. I simply stick them into the three charging plate let it charge and only takes between 30-45 minutes to charge all three. All three charge a little faster than charging my Mavic Pro by itself.

great thread .. thanks for sharing

I just put the stock charge wire from usb power in each of my 3 sparks, charging 3 batteries

Good info...  I don't remember reading anywhere that the spark was compatible with quick charge tech.