Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

General Discussion about large electric scooters and motorcycles and other things with no pedals.
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MrBeeeeee   100 µW

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Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 09 2018 3:03am

Hi guys,

I decided to finally get in on the EV game by purchasing a pretty old Oxygen Lepton just for commuting and tooling around my neighborhood. I loved it, but hated the range that four lead-acid batteries in series gave me.

I endeavored to replace the battery pack with 10 Nissan Leaf battery modules setup in series (84v) and replaced the stock controller (made by Lafert) with a Kelly Controller KLS8415H.

The original controller was rated at 60A RMS and 100A peak with a 48v battery pack supplying. The Kelly is rated at 60A continuous and 160A peak with an 84v battery. The performance gain has been absolutely marginal (except for range). I'm not sure there's been in any improvement in top speed or acceleration. Monitoring the controller via bluetooth it looks like I'm getting expected current values when accelerating, but it drops to 30A as I approach 25 mph or so. If the motor is unloaded, it runs up to 45+ mph in a flash.

I am using the stock motor which is a puny little Lafert 1.8kw inrunner with a hall sensor array.

My question is, if I want to improve my hill climbing and ability to get off the line without any shudder, can I squeeze more performance out of the motor with a bigger controller, or am I just running into the limits of the motor's torque curve?

Here's a photo of motor nameplate.

And an album of the build progress

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eee291   10 kW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by eee291 » Nov 09 2018 3:22pm

Could you post your Kelly settings?

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 10 2018 1:45am

Here they are. I had to take screenshots of the Android App and stitch them together for this.
Attachments
kelly settings 1.png
First page of settings
kelly settings 2.png
Second page of settings
kelly settings 3.png
Third page of settings
kelly settings 4.png
Controller Status when throttle released and still

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eee291   10 kW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by eee291 » Nov 10 2018 3:46am

Try changing your torque ki and kp settings to the highest rated number. I think it's something like 323678.

Also set your battery current back to 100. I think if you set it too night it will just ignore the value and default back to 60 or so.

That should help your hill climbing ability.

Always change the settings withing the range that the app tells you to.

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 10 2018 12:37pm

Thanks! I'll try that and report back after I've had a chance to tackle some hills.

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 11 2018 3:22pm

So changing the PID settings for ki and kp to max definitely seemed to help off the line and hill climbing definitely seemed to improve slightly as well, but I was still hoping to be able to hit 30 mph easier.

I've attached a screenshot of the controller readout of it climbing a relatively gentle grade at full throttle. The scooter's speed topped out at 25 mph during the climb. On that same slope, I was able to reach 30 mph relatively easily going downhill.
Screenshot_20181111-112947.png
So, if my ultimate goal is 35 mph under all conditions, do I need to look at upgrading the controller or the motor first?

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eee291   10 kW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by eee291 » Nov 11 2018 3:46pm

Well with only 60 battery Amps you can't really expect much. If the motor temp doesn't reach some crazy values like 120C with the 60 Amps then I would recommend going to at least 80-100A with a drop-in replacement Kelly like:
http://kellycontroller.com/kls7230s24v- ... -1343.html
or
http://kellycontroller.com/kls7218s24v- ... -1401.html

I'm sure the leaf cells can handle hundreds of Amps but make sure you have a good BMS that can handle more. it will shut down or overheat otherwise.

I had a Johnway Lambda with a Kelly 7218S and a 72V Battery.
Oh man, that thing was a blast! It would do 44mph on the straight and most serious slopes with the same speed :D
The only time it slowed down on one was on a seriously steep hill. I might measure the actual angle of it.

I did have to mount a PC fan to it because the Controller would overheat on anything but the straights with no airflow.
Last edited by eee291 on Nov 11 2018 4:03pm, edited 2 times in total.

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 11 2018 3:53pm

Wait, do you think I'm running into an issue with the batteries not supplying enough current, or the controller not supplying enough current? When I come off the line I'm definitely seeing the readout go over 140A for "Phase Current" before coming down to something more nominal.

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eee291   10 kW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by eee291 » Nov 11 2018 4:02pm

It doesn't matter what the Phase current is.

Power is measured by multiplying the drawn Battery Amps and Volts.
Phase Amps help acceleration and at full speed Battery Amps = Phase Amps

So your max output at any given time is 84Vx60A= 5Kw or less if you have a lower volt battery.
Unless you count that 30-second boost that Kellys have but I sure as hell can't rely on that to get me up a hill :lol:

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 11 2018 4:16pm

So, how should I direct my efforts? Am I battery limited, controller limited, or motor limited? Can I apply a methodology to figuring out what my performance bottleneck is?

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eee291   10 kW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by eee291 » Nov 11 2018 4:27pm

Like I said, Your battery can handle more than enough. Question is the BMS, what is it rated for?
After climbing the slope I would check the Motor temp to see if I can push it further. If the Motor internal temp is above 100C after climbing the slope I'd say it reached its limit.

The Controller is pushing 60A which is obviously not enough. Amps = torque, so going with any of the two I linked above you should see quite an improvement. Unless you have an 84V Battery then you will need an 84V Controller:
80A http://kellycontroller.com/kls8422h24v- ... -1452.html
100A http://kellycontroller.com/kls8430h24v- ... -1453.html

Also, check the Controller temp while climbing to make sure that it isn't reducing Battery current in order to stay cool.

MrBeeeeee   100 µW

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Re: Modifying an Oxygen Lepton with Leaf Batteries and a Kelly Controller

Post by MrBeeeeee » Nov 17 2018 1:53am

I ran it up the biggest hill in neighborhood, down again, then back up and the motor never got warmer than 50C. Controller stayed cool to tbr touch as well.

So I guess I'll get the biggest controller I can mount and see what it takes to make that motor hot.

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