Questions about Batteries

EFOIL.builders Electronics (ESC, remote, batteries)
21

Hello Malveymonster
Depending on which engine you want to use. I like to use the cells because they are inexpensive and last a long time if used properly. In addition, they are inexpensive to replace, or a 2nd and 3rd pack allows very long travel times.

22

Your C rate bill is incorrect.
the 20Ah cells can be permanently 240A
the 12 Ah that I use 144 A. More than enough to foil;)
Incidentally, my cells are 1.5 years old and over 300 cycles, mostly use up to 5 or 10% of the rest. It cannot be denied that the cells are light, inexpensive and usable to replace them faster.
Greetings Frank

23

Sorry my C rating understanding isn’t as wrong as your should be right :

I used those lipo brand for more than 70 charges , running 8s 32ah on my first build , 250A pic on start , constant + 140A discharge , those were my conclusion

Your setup works , why ? Because you use 24ah for 40 min at around 32ah so there is left around 3A I would say , 3A x 12c = 36ah possible so you are well and that why is working I think

Now take the same battery and a 60Ah constant draw , It will swell , voltage sag and heat if you take them down to 3A

24

Hello Alexander

  1. Why 140 A … a lot of energy that is wasted.
  2. I also used my cells in the jetboard, with currents of 150A
  3. that’s why I wrote it, it depends on the motor set up …
    Greetings Frank
25

I’m planning on using these for my build.

https://flipsky.net/collections/electronic-products/products/high-current-fsesc-200a-60v-base-on-vesc6

How can I figure out whether or not this setup would work with two of the batteries I listed above?

Thank you for the help, I really appreciate it.

26

Look at the measurements from other users and compare the props they use.
If you stay below 50A average current to follow Alexander’s recommendation, you can use the cells well in my opinion.

1 Like
27

Sounds good, thank you.

28

Yes a lot energy wasted : 30% , small motor 40mm , low voltage , speed ( high pitch prop) , heat , weight , no skills

Everybody do as they want , but for those lipo brand , for what I have tested and read , true constant 3-4C is what they like

29

Edit : 2 battery ( 20ah) would be good , 4 : good running time for practice as you would be falling and re start a lot at the beginning

But to save weight I will go with 2 packs of 2 :wink:

30

4C = 80A startpower
2C = 40A continius

Perfekt :+1:

31

Correct me if I’m wrong, but with 20000mAh and 12C constant discharge rate and 24C peak discharge rate, I should have a discharge rate of 240 Ah continuous and 480 Ah peak. The ESC has a maximum of 200 Ah. What does this mean for the battery? Will it stay in a good condition if I stay under the continuous discharge rate, or are you guys recommending I stay at a lower rate than that?

32

It is always better to stay as low / sensible as possible.

I don’t like the design of motors, not effective, too heavy and therefore too expensive. In addition, more electricity is often wasted with 3 knifes props.
All things that put unnecessary strain on your batteries.
i foil with 750 Watt and 20Km / h (max 26Km / H).
Motor 70 euros
ESC 70, -
Battery 2x 6s 12AH (200, -)
Flight time depending on the prop 40min.

But the batteries should also be enough for your application.

1 Like
33

Thank you so much for the help, I was getting a lot of mixed feedback, but I think I understand much better now.

34

Good to know that FLIPSKY have just changed their motor page. They propose four variants between 100/120kv and 10/12mm shaft. In 120KV, they offer a 10mm unthreaded shaft (variant ~9559) and a 12mm threaded shaft (variant ~5095 your choice).
Looking forward to reading your data with VESC Tool showing the differences between a Flying Rodeo propeller and Solas or 3D printed ones :wink:

1035×675 114 KB

35

Hi. This is also a question I have been thinking of a lot lately. My first plan was to use 6S lipos two in series which I could double parallel if nessessary. First investment would ne around 400€ and then perhaps another 400€. Now I have an offer of 1050€ for 13S13P custom battery pack from 18650 li-ion 8A 3450mAh cells. Any opinnions which way to go?
I would have to build a waterproof box to both.

36

Great results! What kind of foil are you using?

37

  1. 30q doesn’t have the best cycle life, i would go for whatever cell you can find on a good price. Today, for a large battery and if looking to spend for performance then i’d look for a high energy 21700 4.5-5Ah cell, then read some tests.
    Some examples here:
    21700 & 20700 - Li-ion - Rechargeable batteries: 4000mAh - 5520mAh and In Stock | NKON

  2. Splitting the cells into lower series count can give you the possibility to use a cheaper charger. I wouldn’t do it since it’s not worth the trouble to me, i’d just get whatever charger needed. Splitting the cells into lower parallel count gives you the possibility to choose either a light nimble ride or a long ridetime. This is an ok option to have.

  3. bms or a balance charger, both are ok options. I use bms on all builds after killing some batteries from handling mistakes made by yours truly😀.

  4. normally new cells from reputed sellers aren’t faulty, it’s not mandatory but good practice to get a tester and test capacity and internal resistance of the cells before building the pack. Whatever you do, don’t get cells from unknown sources, so many have been scammed over the years - and the battery is the most invested part of any build!

  5. i’d stay away from daly bms, ANT bms and nonames due to previous experiences, get a smart bms with programming and bluetooth.
    I’ve used LLT bms on a few builds without issues.

  6. there are a gazillion functional chargers out there, it’s really not a critical part of your build. Everything i’ve tried has worked for me. Maybe others can point out their favourites.