I'd building a pack of 18650's in a 12s, 4p configuration. The application is an electric unicycle which (I hope) will use a regenerative BLDC controller. Since Li-Ion are extremely sensitive to how they are charged, is it wise to use a regenerative charging? Or will everything be okay as long as I limit the motor controller to re-charge the batteries below a set voltage and current?
Using a Regenerative Controller with Li-Ion Cells?
- Thread starter HacknMod
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Hillhater
100 TW
Im intrigued as to how you plan to control a powered unicycle ?
RC hand controls maybe? but how do you "modulate" for balance ?
It would seem that some form of advanced torque or pressure sensing in the cranks would be needed.
Torque reaction from the motor will be "interesting" also !
RC hand controls maybe? but how do you "modulate" for balance ?
It would seem that some form of advanced torque or pressure sensing in the cranks would be needed.
Torque reaction from the motor will be "interesting" also !
liveforphysics
100 TW
Justing made an electric unicycle, and it works great for him. You should really use LiPo rather than some crappy 18650's though, weight and space matter a lot on a unicycle. In Justin's case, I think he said a single 6s5Ah LiPo brick would last over 100miles if I'm not mistaken. Some crazy low wh/mile.
Hillhater said:Im intrigued as to how you plan to control a powered unicycle ?
RC hand controls maybe? but how do you "modulate" for balance ?
It would seem that some form of advanced torque or pressure sensing in the cranks would be needed.
Torque reaction from the motor will be "interesting" also !
Forward/back tilt is handled just like a Segway: using an accelerometer and gyro. Left/Right lean is up to the rider to maintain.
liveforphysics said:
I found a few electric unicycle posts by justin_le, but they don't discuss the battery tech much?
Hillhater
100 TW
liveforphysics said:
1 Whr/mile ???????????...thats not giving much assistance then ?
something makes me think a uni cycle would use power when not even moving,..just to balance , so how could it have a lower consumption than an Ebike with 2 wheels ??
I know Segways chew through battery power real fast.
liveforphysics
100 TW
Justin didn't write much about his battery, because I think it was just a single 6s 40c lipo brick from HobbyKing if I remember right. I actually tried to ride it for like 2seconds, failing badly. Lol
He jams on it though! Flys along weaving through objects with better precision than a bicycle could do rides it down stairs and really goes much faster on it then I ever would have expected was possible for a unicycle.
He jams on it though! Flys along weaving through objects with better precision than a bicycle could do rides it down stairs and really goes much faster on it then I ever would have expected was possible for a unicycle.
ohzee
100 kW
Id love to see some video of that - he have any up ?
Sorry to jerk this back to my original question, but: Is it safe to use a regenerative controller with lithium (poly, ion, anything) batteries? Or is there additional protection circuitry necessary? Or... will everything be okay as long as I limit the motor controller to re-charge the batteries below a set voltage and current?
AussieJester
1 TW
liveforphysics said:
Yup agreed Luke :wink: i already gave him link to the nano teks on HK in the other thread he
started about the 18650 li-ion cells
KiM
Since regen is electrically the same thing as plugging in the charger, then as long as it is limited to the same max charging rates it would be while charging normally, it would have the same effects.
Hillhater
100 TW
Other than the "cool" factor for bragging rights, ..i think you are wasting time effort, and money using a regen system...certainly if the consumption is anything like Luke suggests.
Its not as if this is going to be a primary transport device, with high speeds and range issues !
you will have plenty of other controller ( and control) issues to figure out without the extra hassle of regen.
Its not as if this is going to be a primary transport device, with high speeds and range issues !
you will have plenty of other controller ( and control) issues to figure out without the extra hassle of regen.
Awesome, thanks for the replies everyone. The only question I have now is...If I don't use regen, could I use an ESC? I started a new thread about this.
liveforphysics
100 TW
Lol... you have so so much to learn.
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