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Super Capacitor & Regen

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Posts: 96
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(@socomods)
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Joined: 4 years ago

I am playing around with an idea for using regen to charge a super capacitor (array of high capacity caps), that can be used to give a brief boost to initial acceleration - its a big change to the way the bike works, but has the potential to make the Soco allot safer to run in cities and busy roads

I don't know anything about the way the socos regen works, but i have allot of experience working with high voltage & capacity capacitors - i would still welcome any input from anyone who may have experience with super capacitors

does anyone have any technical info & data about regen in the soco? (preferably specific to the TS, as that is my bike)

Once i have that info, i will draw up a circuit schematic (will drop it here for anyone interested) and build a prototype to test 😎 (if i cant get enough info on regen, i can still test by charging via the battery, not ideal, but also has potential uses - i think the ability to switch between regen and battery charging could be gokd)

 

first prototype will still be limited by the maximum power the motor can handle, although as the TS maxes out at around 2.5k, that gives some headroom for brief boosts upto 3k - eventually i want to switch in an 11kW motor, and has the potential for some serious acceleration (assuming the bike can handle it and remain stable)

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Posts: 177
(@flyingelectric)
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Joined: 5 years ago

In theory it sounds cool and awesome but compare this

A big capacitor or capacitors in the size of the original battery and weight maybe only has the energy content as one (1) 18650 cell. The original battery consist of about 150 cells.

2.7v Green cap capacitor has a real capacity of 100mah or 0,1ah I think and cost 5$ while you can get one 18650 cell with 3200% larger capacity for the same price. 

However true is that a cap bank is good for example as additional power for a lead acid battery in a car that's getting old to get more use of it.

Capacitor, measuring voltage and more:

https://www.youtube.com/watch?v=uG8KtlLtbVE

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Posts: 96
Topic starter
(@socomods)
Trusted Member
Joined: 4 years ago

the comparison is not quite right, because a capacitor is not providing sustained power, and is able to deliver significantly higher current over a short period, in comparison to lithium over the same time - this is not about providing additional capacity and range, but increasing acceleration potential

 

i'll post my calculations up when i get home (also we are talking about super capacitors, so banks around 1kF @ 64V as a start) - super capacitors are the future of EV (there are at least 2 prototypes which use them exclusively)

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Posts: 96
Topic starter
(@socomods)
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Joined: 4 years ago

Capacitive energy: (for simplicity i am ignoring quite a few things, but you should see the potential...)

E = 1/2 * C * V^2

0.5 * 1000F * (64V^2=4096) = 2,048,000 Joules

(max energy it can store under ideal conditions and with maximum charge available)

potential power:

W = E / t 

if we set our discharge time at 10s, we get:

2,048,000 / 10 = 204.8kW

obviously this is the theoretical power available and not real world, and is still limited by charge

the current available is

i = P / V

204,800 / 64 = 3,200A

limiting factor will be Regen, rather than the caps, i don't yet have the data for that - that will tell us how much energy we can actually store in the capacitor - the above calcs are largely irrelevant, other than to show the max potential

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Posts: 177
(@flyingelectric)
Estimable Member
Joined: 5 years ago

OK

You need a 71,4v capable cap (17series*4,2voltage max) = battery max charge, normal charge 69,7v

Some capacitor sizes: 32v, 63v 100v 

If you try it out it will at least "up" the efficiency at start of accelerations. Potential from the regen energy is the vehicle mass. A bike is 10:1 in size of a car. Potential can be 3-10% regenerated energy from a fully charged battery. 

You're question if the capacitors will be enough to store regenerated energy. The battery connected on the Super Soco can do this without the added capacitor already.

How does regen work? Instead of pushing energy in three phases into the motor. This energy when regen is active goes into the controller and then back to the battery.

I was also thinking how am I gonna calculated mah, the energy a capacitor can store? From the video linked before, a 2,7v x 500F = 100mah or 0,1AH. Doing the same calculation. It wasn't really a calculation as the F's stand for energy capacity I joules or whatever. 63v x 1000F = 200mah 0,2AH. SO a 63v cap with double F capacity but higher voltage, still only doubles the mah. Calculating watt hour for 63v cap (63 x 0,2 = 12,6wh )

Maybe that is wrong. I'm not 100% sure but at least closer to answer than the start. Also 2mil joules is like 500wh and its calculated per hour so 10 seconds (1/60/60) hours at that power equates 0,15wh.

I found this website and I think it can be helpful to calculate jouls to wh and more:
https://www.rc-electronics-usa.com/battery-electronics-101.html

 

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