Went out to test a NCR18650b (4S4P) battery pack we quickly slapped together in our floppy Skywalker (taken a lot of hard landings). Our hope was to get around 90 mins flight time. The wind was constantly hovering around 20kph, so we never really went for distance.
After some time in the air we got to 60km distance, then 70km, etc. At 90km we decided to fly the battery until the motor cut out, luckily it didn't - went to to 13.2V under load.
Plane: Skywalker 2014 1800
AUW: around 2kg, not sure
Motor: Sunnysky 600kv X4108S
Prop: APC 12x6
Batteries: 4S4P NCR18650b 13600Mah
Battery weight: 812g
AutoPilot: APM2.6
Total Distance flown: 102km
Weather: Wind 20kph, sunny, 30°C. Altitude: 1634m ASL
Time flown: 129
TLOG: TLOG.zip
Comments
Hi everyone, since the Tlog is shared, I uploaded it to Exmaps and its available here: http://exmaps.com/e40c4f lowest voltage under load was 12.72V (3.2V per cell), total mAh 11704 and 114.4 mAh/km. Not to sure why a sudden increase in altitude towards the end?
Thanks guys.
We decided to throw caution to the wind and soldered the batteries ourselves. I wouldn't say it's safe to do so, but it worked for us by using hot soldering iron (150W) and applying no more than 3 seconds of heat at a time.
A more important thing to consider is that the whole battery casing is negative and there is very little separating the positive side from the casing - on one solder I did create a short by accidentally burning through the very thin insulation - I would recommend using insulated wire (wet noodle) for these connections.
This is beautiful. How did you practically solder your cells together? Spot soldering? Other method?
Nice one let me give you a 100km badge. I might have to get some of those batteries for my Skywalker. Well done.
-
1
-
2
of 2 Next