DIY Li-Ion batteries for use in UAVs and math

Great knowledge love it.

Motor cutoff is definitely something to keep in mind, happened to me at 60m, wasn’t nice to watch :wink:

For magnetic field, never happened to me, no interference on imus.

I always thought that charging with BMS, you don’t know what happens in each cell and it becomes like a black box. So I actually chose to use balance cables. What charger do you use for that?

I use something like this for charging

And this BMS

I plug it into the PC from time to time to monitor health, but you can also hook it up to BT module.
(Never tried that).

1 Like

Adding a few bits and pieces and you get smart battery
Love it

Very nice discussion , hope to find a magnetic disturbance solution here !!!..made myself a 6S2p (outof Sony matura’s VT6 3000Ma -30A ) but cannot use it because of this …see YT .

If this is the battery you’re going to end up using, why not just do a compass calibration with the battery installed in the quad?

3 Likes

I did and it flew (bad) , but then i have to disable one of two compasses also they see differences.
Problem is there seems to be no way to completely disable the pixhawks internal ?. Also …its a lot of hassle to re-calibrate every time when i use one of my other battery’s (lipo) again. So not the best solution for me.

See this post about the manual compass prioritization in 4.0.4rc2.
It enables manual control of compasses priority and enable/disabling.

@ Rubiksman …Thanks will investigate ( read ) …the Li-ion is on hold . Obstacle avoidance on top of the list .(for now )…update …did the read ! interesting !..update did the read again…will test it !

I have a quadcopter
With specific actions
F450 frame
920kv motor
1045 Propeller
30A Simonk Esc
Apm2.8Fc
NEO M8N GPS
FSI6 RECEIVER AND TRANSMITTER

I USE 2.2AMP 30c BATTERY PACK TO MY QUADCOPTER AND GET A FLIGHT TIME OF 7 MIN. I want to increase my flight time the way I found to us Li ion battery pack iam unable to calculate how many amps I required and which Li ion cells suite for me and in which configration

My quadcopter weighs 1.2 kg without battery but soon I will reduce weight to less than 800 gram and use Li ion cells

Pls help me I dont know the amp draw of my quad pls say how to check sothat I can calculate

1st replace the obsolete APM Flight Controller. In the mean time you can use eCalc to approximate current for your craft.

Can u pls say why I have to replace apm2.8

Arducopter hasn’t supported the APM since 2015 with firmware Rev 3.2.1

Can u pls send ur log data I will analysis the current draw and come to conclusion

This is a bit off of the Li-Ion topic covered by this post - but I have been recently using the Semi-Solid State Li-Po’s that have popping up around the industry. The one I have is from T-Motor and is branded as a T-Drone battery. It has been working out really well so far - giving me a 30-35% boost in flight time! Granted - I have them running on a fairly large quad running 22" propellers. I have yet to require more than 2C draw from the battery - so I’ll have to test that on a bench sometime soon. Regardless - liking these batteries so far. I can now hold a 1.5kg payload for 45 minutes (20% reserve) w/o a sweat!

The battery I am using is a 6s 30Ah rated at 5C. As mentioned above, I haven’t tested the 5C claims yet. It is a perfect replacement (in terms of size and weight) for the regular 6s 22Ah Tattu batteries that I normally use.

1 Like

We can give first priority to compass in GPS module, which we always keep away from battery and escs

Hi , will try …but will take a while.

Hi, did you ever try the EMI shielding on a liion pack? My quad uses Lipo or Liion and the position of the one compass is giving some EMF issues. I would prefer shielding options above disabling the compass, moving it far enough away is also impractical.
DJI used similar absorbing shielding on their old Phantom 3 drones, the new ones no longer have it so guessing that they now just compensate for it via software, that won’t work when using different battery configurations.
The thread was an interesting read, thanks.
My packs are 17,5Ah - 14s5p (882Wh) that gives me <3C on 100% power, normal unloaded flight is <1C, added to that, the cells are individually ventilated with forced air (may be over kill).

I tried mumetal shielding. Worked well.
I used copper tape and mumetal. I think thats what its called.

Thx, just ordered some, will give it a go. I can find very little on its use in UAVs, I played a bit with it for GPS interference a few years ago, not yet for compass.
What thickness did you use?