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    • In my understanding 10C means max current is 10 x capacity (in AH) and does not depend on s (voltage).

      So the Multistar 10 Ah 10C gives 100A max constant current - in theory. I think in fact it will give 50A - still enough for my ship.The cell weights 810g what is the lightest Lipo of this capacity i found. BTW - 58€ at HK.

      Setting battery failsafe to 12,2 V (3,3 V x 4s) leads to 9,1 Ah "usable" capacity - only for testing, 

      The Keeppower LiIon 18650 cell i use is ratet 3,2 Ah and 10A cont. current (what means 3C). It weights 48g.

      So to get the 40A I need for my copter i use 4s4p what means 12,8 Ah and still 3 C at 810g (wiring...)

      Setting battery failsafe to 10,1 V gives only 10500 Ah. 

      For better testing you will have to use watts instead of Ah because of the different voltage.

      So although the LiIon cells are lighter per capacity the advantage is not so big.

  • MR60

    What are solaluna 1245 props?  Tried unsuccessfully to google them.  

  • Can you point me to a solution that I can use to test my current lipo batteries? I recently experienced a crash where my quad literally fell out of the sky after only using 1500mAh from a 5200mAh battery. At the time of the crash I was increasing the throttle, trying to accelerate. After the crash (there was very little damage), I started it up and all 4 motors and ESCs worked fine. I've been trying to figure out if it was definitely battery related, or something else. The battery balance charged okay, but I have not flown again with that battery.

    Thanks

  • I'd love to learn more about your quad. Mine started as a stock QAV400 kit that comes with 1100kv motors and 8" props. Its very fast but the frame is fiberglass and aluminum so its heavy. I've built my own frame to replace the stock frame but I'm still using the 1100kv motors but with 9" props. My new frame is less than half the weight of the original, and it allows for up to 10" props. I realize I'm sacrificing flight time for speed, but I've had it up to 62mph! (100kph)

    I'm planning to try some 740kv motors next. Where can I learn more about how you're testing different props?

  • Here is a great comparison that goes along with the general conversion (C rating sustainability).

  • Lipo and Li-ion are chemically the same thing with different medium/packaging so the rivalry in advancement that you suggest isn't actually a real thing.

    • MR60

      Sorry, not correct.  There are currently 3 workable forms of Li batteries, each as different in performance as incandescent, fluorescent, and LED lights.

      1) LiPo

      2) Li-Ion

      3) Li-S

      If they were the same, then why is the charging requirements different?  Why is the voltage different (3.6 vs. 3.7)?  Why are the discharge rates so different?

      Each uses a slightly different chemistry.  Each makes a different trade between electron storage, discharge rate, and weight.  You can run a LiPo easily at 20 amps or more.  Try that with a Li-Ion and your ship falls out of the sky.  With a Li-S it is even worse,  But Li-Ion delivers 73% more electrons per gram.  And Li-S delivers 1.5 to 2x more than Li-Ion.

      Huge differences.  I've used LiPo and Li-Ion.  Have studied their differences and have built craft for both.  The latter ship only draws 8 amps to hover while carrying a 2kg payload.

    • The point is it is the makeup of the pack that determines the characteristics rather than being different technologies with different fundamentals as the marketing leads you to believe.  @Forrest the statements you are making about electrons per gram simply do not apply consistently to all Li-ion batteries for instance but may well do for a specific type.

  • Interesting post. Which Li-ion cell are you using, the HG2's ? Looks like a 20A 3000mAh cell, which is about 6.6C.
    I'm using the GA's at 10A and 3500mAh. I found the last 40% pretty unusable for adequate go-around power (fixed wing). I need cruise at 120w and I want at least 240w available if I need it. I'm using 12 cells also. Do you think I will be better off with lower capacity, higher C cells like yours?
    • Moderator
      Hi iskess,

      The hg2 is a good cell as long as it is genuine, along with the sony vtc range it is one of the most faked cells out there. Have you tested the cells on the bench under load? We have noticed voltage sag in most lipo batteries with high current draw towards the end of the capacity but this is not something we have seen with li-ion cells in all our tests. Sorry to ask but can you be sure those Panasonic cells are genuine? Certainly I can say that our packs have never shown that issue. Hope it helps!
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