Capacitor Battery Bank

Hello everyone,

I’m developing a battery bank using FM capacitors


  1. The main objective is to be able to use it in projects where battery recharging happens quickly.

  2. I want to build a power system for my Multirotor using cables ( tethering). Where it will have a UPS with a battery bank like that contingency being fed constantly.

I thank you all for sending criticism and suggestions

Best Regards


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The PDF is missing, looks very interesting!

So 6x550Fx2.7V equals 10937 Ws, which around 3.06Wh.

Not counting the discharge curve and conversion losses, it can fly a copter which needs 300W to hover around 37sec (best case).

From the other angle, the datasheet states 5.69Wh/kg specific energy and it does not count the mass of the PCB. An average LiPo has 100-300Wh/kg…

Perhaps I’m short sighted but don’t see the use case.

Thanks for the comments, they are always very useful.

I implementing a project using NVIDIA Jetson 2 using a drone connected to a power cable.

The idea is that this drone through a set of 4 cameras can identify and control all traffic within an industrial plant through facial biometrics using a market library called OpenCV installed on Jetson inside the Drone.

The whole part of Jetson is ready we are thinking about the cable solution via drone and possible problems that can happen. Because of this we thought about using capacitors in parallel. As soon as the drone cable is broken, the Jetson platform will identify and have time to put the equipment down safely.

The capacitors are just a parallel power resource and the main source backup will be a lithium-ion pack Sanyo UR18650E.

Looks interesting. I hope it’s OK, I moved one of the pictures to the top to make it look prettier on

Sorry Fabio, I still don’t get. (I know I’m stubborn) But you got this nice balancing board from banggood, ( and put it in front of a UR18650E batteries which is used as a safety battery in a Tethered drone system.
Based on the payload and the length of the tether, the power required for hoovering could be around 500-1000w, and when safety battery engaged it needs to provide power to safely land the copter.
(correct me if I’m wrong)
For the landing we can assume that the safety battery must provide current a little below the power requirements of hoovering and handle some peaks (for counteract wind gusts and slowing the descent at the final land stage).
To keep safety battery small as possible you plan to use this capacitor bank to fill in the gaps where the power requirement of the copter is larger than the discharge rating of the batteries ?
It looks like a good idea but what happens when a wind gust force the copter to increased power need and discharge the capacitor bank. That charge will go back to the capacitors from the battery while it still keeps the copter in the air, unless you put some limiter there the current draw will be limited only by the internal resistances…
I’m not saying that is is not possible, but requires lot’s of design and test, and put’s unnecessary point of failures into a subsystem that is there for safety. A small,large discharge rated, LiPo battey that provides enough power for landing from the maximum tether height provides less complexity and more realibility. (IMHO)

One more thought. The board you pictured is for connecting six capacitors in series, which gives you 6x2.7 Volts, 16.2V (it designed for 12V car audio systems). If you use 4s battery, then a fully charged batteries will give 16.8 (16.4 if charged only to 4.1), and not counting in if you using regenerative breaking esc the voltage at the battery can be significant higher…


I thought in a solution like that for an emergency battery for a H2 cell fuel big octo-copter. In such a project, I could manage the extra weight, but I could get beefit of the high discharge rate for limit situations.

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