Hi group,
Here is another Kickstarter project with technical challenges:
https://www.kickstarter.com/projects/shawnpwest/30-second-charging-rechargeable-batteryIn the FAQ the stated capacity is 1150 mAh.
So we have 1.5V x 1.15A x 60 x 60 (conversion to seconds) = 6210 Joules.
These Lithium Ion super caps:
http://ca.mouser.com/new/Taiyo-Yuden/taiyo-yuden-lithium-ion-capacitors/in the package that is close to fitting an AA battery (12.5mm diameter x 35 mm) is 40F
Charge these to 3.8V we have:
1/2 CV
2 = 0.5 x 40 x 3.8
2 = 288J
If you allow for the fact you can discharge to 1/2 the maximum voltage, you can extract 3/4 of the energy:
288 x 0.75 = 216 Joules
We only have 1/30 of the energy required
Charging If the rechargeable battery had a useable capacity of 6000 Joules, we would need 8000 Joules.
8000J / 0.5 x 3.8 x 3.8 = 1100F
We would need 1100 Farads.
I = C dv/dt
= 1100F x 2V /30s = 73 Amps
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/facepalm.gif)
I detect a few problems
![Confused :-//](https://www.eevblog.com/forum/Smileys/default/confused0024.gif)
Regards,
Jay_Diddy_B