Recent content by gigelu

I have discharged the original battery and the lg hg2. The results are: lg hg2 - 45.2g, 9,986mah 221 w/kg original - 67.3g, 12,192mah 181 w/kg I have calculated that with: 4 cells, we'll fly 16.74km 5 cells, 18.69km 6 cells, 21,72km 7 cells, 23.38km 8 cells, 28.66km 4 cells and 8 cells...

... if I use a step down converter, I won't be able to achieve 100% energy conversion efficiency; 92% is the best I can hope for. This will cancel the advantage we get by using a higher density cell :-( Maybe I should try using 4 cells in series first. Hopefully I will not upset my Mavic ....

Please find attached pictures with the batteries' weight. Using 5 x lg hg2 batteries, the weight of the aircraft is increased with only 28 grams which IMO is negligible. We should be able to fly 20km easily and using the new propellers from Mavic Platinum this distance should be even longer.

Regarding the case, my intention is to allow the 18650 batteries to be removable. I am not happy with the idea of spot welding due to the high cost of the welding machine. At the same time, the manufacturer of the product will not need to go through the pain of complying with shipping...

Hi! I intend to start developing a better Mavic battery from ground up and licence it as open source. This will include PCB, firmware and battery case. I could not find any other similar projects therefore I have started my own. Project can be found at: github.com/kopern/smarter_mavic_battery...

Did you try to fiddle with the mavic's configuration params? suggestion: g_config_bat_config_emergency_voltage 3000 -> 2600 raw_bat_level_1 3960 -> 3250 raw_bat_level_2 3600 -> 2800 g_config_bat_config_bat_limit_limit_vol_min 3300 -> 2700 g_config_bat_config_bat_limit_limit_vol_max 3700 -> 3500

They look right to me: The first part of the flight was done with tail wind (~4.5 miles). On return, I noticed the wind and had to floor it (Mavic's flight params were modified to turbo+++, which allowed me to spin the motors over 8500rpm). Finally, I realised that I could not make it back and...

Screenshot of the Flight Data Viewer, showing the current used. the end of this flight is captured in this movie:

There's no need for an ampmeter. Flight Data Viewer will show the used current:

Oops. It looks that I keep making mistakes :-) Let's recalculate: 6 batteries x 12.6Watthour = 75.6 Watthour. (note I am being idulgent. The cell cannot store 12.6Watthour, it will store around 11Wh) How did they get to 120Watts? Anyway, the battery was removed from their website. @TiTaN: If...

It's great if you can fly 52 minutes. But the question is: can you get more out of these batteries? For example, if you combine chemistries, it looks that you'll be leaving 40% of energy unused.

I was reading these: https://www.nkon.nl/sk/k/ncr18650ga.pdf www.hurt.com.pl/prods/bat/_li_ion/ncr18650ga.pdf https://www.nkon.nl/sk/k/hg2.pdf

This kind of calculation is incorrect. I have given detailed explanation why in my previous posts from today and yesterday. Panasonic mentions clearly 224W/kg and LG is even clearer and apart from mentioning 240w/kg they give a detailed table: 10A -> 9.8W, 20A ->9.2W

I did not know that. Thank you for the links and I apologize again for offending you.

Are we looking at the same datasheet? 13.86W*9pcs = 124.74Watt. Maybe this is the way Titan has calculated the advertised power....