Using 350 mAh - 25 C Battery on CF2

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tugayalperen
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Using 350 mAh - 25 C Battery on CF2

Post by tugayalperen »

Hi all,
We wanted to try installing a bigger battery like in the picture (3.7V (1S), 350 mAh - 25C) on CF2. Yet, it does not even takeoff. When we send commands to take off it either turn itself off or some propellers are strangely rotating while others are stationary. I am %100 sure about our external positioning system and commanding code because at the instant I switched to original battery (1S, 240 mAh, 15C), everything works fine. Also I can assure you the problem is neither physical integration of battery nor the weight of platform. They are perfectly fine.

Is there anything I can do to work with that battery?
battery2.jpeg
battery1.jpeg
cf-battery.jpeg
Last edited by tugayalperen on Tue Mar 05, 2019 9:02 am, edited 1 time in total.
tobias
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Re: Using 350 mAh - 35 C Battery on CF2

Post by tobias »

Sounds like something is wrong with the battery. You don't happen to have another battery of the same type to test with? I'm guessing it is either the protection circuit in the battery or the cables/connector that has bad contact. To check that you have to open the top part of the battery.
tugayalperen
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Re: Using 350 mAh - 25 C Battery on CF2

Post by tugayalperen »

Hi Tobias,
I have ordered only one to test it if it will work or not but the situtation is more complicated now :) So you think that kind of battery with similar specs should work with crazyflie, right? (I can not see any reasons to not).

I was checking this post (viewtopic.php?f=11&t=2127&hilit=lipo) and you have said that one needs batteries without protection circuit. So do you think there might be a malfunction on the protection circuit of my battery or I should have removed that circuit already to use with crazyflie? Anyway today I will write to seller to change battery or I will buy a new one (maybe different brand) and try it out.
Last edited by tugayalperen on Tue Mar 05, 2019 9:03 am, edited 1 time in total.
tugayalperen
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Posts: 19
Joined: Mon May 14, 2018 8:33 am

Re: Using 350 mAh - 25 C Battery on CF2

Post by tugayalperen »

I also did some tests, want to share it here. First I have connected CF to a desktop power supply on 3.9V. Holding it on my hands, connected via CF Client then tried to take-off. Just by an inspection, I saw numbers higher than 3.8 A for a short time. The stock battery is able to give (0.25(Ah)*15C=)3.75 A continiously. So for stock battery, numbers seem fair. We have a capable Li-Po charger. I used it on discharge mode, set it to 3 A. Stock battery worked well for this test. However, with other battery, charger gives low cell voltage error around 2.4A even though battery is fully charged. From here, I assume the problem is battery as Tobias said. Today, I will try another battery with different brand with exactly same mAh and C rate. I will share the results.
tobias
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Re: Using 350 mAh - 25 C Battery on CF2

Post by tobias »

I would actually recommend batteries with protection circuit as they are harder to damage. If you want max performance though the protection circuit adds resistance so then go for one without.
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