KHB - Project eTurd - 2000W - LiFePO4 48V 24Ah

K

kreal

1 W
Joined
Jan 18, 2016
Messages
59
So I finished my daily driver e-scooter: https://endless-sphere.com/forums/viewtopic.php?f=12&t=105234 and want a new project.

Welcome to Project eTurd:

C9fo9UA-SpqtlbRP6BR5IA.jpg

I was thinking about using a QSMotor 3000w 13870h chain driven 14T front, 45T back, with 17inch wheels.

The only controller I have right now because of virus and shipping is halted is a generic no name 1500watt, however it goes up to 64v, so might be able to do 23amps!

4e185136c963f589e7dddbe04664a391.jpg_720x720q80.jpg

My goal is to accomplish something like this:

eTurd.jpg
Screenshot 2020-04-02 at 21.21.32.png

I will use the back from a Honda MSX, and the front from a Suzuki step 125
 
I think you'd better copyright that name. Might be stolen by some electric commode corporation types.

That's a good looking bike! I've been wanting to do something w/ those 12V 5AH batteries ever since I discovered that you can buy an 8 pack of them (see link below) for under $100, and that's delivered to my door. Might be just the thing for my eTrike project. Good job.
https://www.batterysharks.com/12-Volt-SLA-Batteries-s/1213.htm
 
kreal said:
What would you suggest to have really good acceleration with the 3000w motor?

14T in front and 65T in back ?

The lead acid batteries I have for this can pump out around 60amps
Click to expand...

1:7 is about right for wheel popping acceleration, coupled with a 500A (phase) controller. Those lead acids and that controller won’t do it if you want ”really good acceleration”
 
I think you will not have much fun with 5Ah.

Simplified calculation:
3000W/72V -> ~40 A
So with your 5 Ah you can operate the motor at full power for at about 0,125 hours (1/8 of an hour)...
This is 7,5 Minutes, or 450 seconds...

I am also planning to begin with LeadAcid, but at least 20-30 Ah.
 
Why bother at all with lead acid? It doesn’t have enough performance for this motor which can take +20kW. A 72v 60A 5Ah pack will deliver too little in every way.

If looking for cheap then buy some chinese lipo or even better some used hybrid car cells. Lead acid is never worth it (unless you have unlimited space and weight. On a bike you don’t.)

I’d go as far as to say that the only place for lead acid these days might be in a home energy storage system (if you get the batteries for a very low price.) They don’t belong in EV:s anymore.
 
kreal said:
Still work in process, I think this might be the final reversion, just don't know if the shock is to steep?

IMG_20210515_005533.jpg
Click to expand...

Not sure about the angle of the rear shock. But I'd say its upper fixing point is designed too weak.

And in my opinion, the steering angle (front fork to frame) is way too flat...
 
Elektrosherpa said:
kreal said:
Still work in process, I think this might be the final reversion, just don't know if the shock is to steep?

IMG_20210515_005533.jpg
Click to expand...

Not sure about the angle of the rear shock. But I'd say its upper fixing point is designed too weak.

And in my opinion, the steering angle (front fork to frame) is way too flat...
Click to expand...

The rear shock fixing point will be reinforced with bunny ears.
 
Brake caliber added, and adjusted the shock for better angle.

Found a second hand foot brake, even though it's not really needed on a electric bike :)
1.jpg

I'm thinking a much larger battery could go here, as I see on many others, as I made plenty of ground clearance.
2.jpg

Motor will go here or similar I think.
2.jpg

Will most likely use the new one.
New-Arrival-QS138-70H-V3-72V-100kmph-Mid-Drive-Motor-with-1-2-35-gearbox-for.png_.png

Also made air intake for cooling in the front.
Screenshot 2021-05-16 at 04.21.15.png
 
Elektrosherpa said:
kreal said:
Still work in process, I think this might be the final reversion, just don't know if the shock is to steep?

IMG_20210515_005533.jpg
Click to expand...

Not sure about the angle of the rear shock. But I'd say its upper fixing point is designed too weak.

And in my opinion, the steering angle (front fork to frame) is way too flat...
Click to expand...

Also will be reinforced with seat, like this.

Screenshot 2021-05-17 at 05.30.00.png
 
Interesting build but please bare this in mind for lead-acid:
https://en.wikipedia.org/wiki/Peukert%27s_law
 
stan.distortion said:
Interesting build but please bare this in mind for lead-acid:
https://en.wikipedia.org/wiki/Peukert%27s_law
Click to expand...

Thanks, yeah I'm going with LiFePO4 instead, as they should be the safest type, in case I crash in the jungle.

Also I found this motor kit very cheap, the QS motor is to expensive still for this build.

d89d48be23fcdf93ae54cad03e6c747e.jpg_720x720q80.jpeg

around $130

However I am unsure of the AH I need for battery to support 2000w since motor is rated for 42A

I can get a really good and cheap 48v 12AH ( 16S-2P )

  • Battery LiFePO432650 3.2V 6Ah(6000mAh)
    Charge and discharge standard: constant current and constant voltage (CC/CV)
    Nominal voltage: 3.2V
    Charge upper limit voltage: 3.65V
    Lower discharge voltage: 2.0V
    Nominal capacity: 6000mAh (6AH)
    Measured capacity: 6000mAh or more (6A test)
    Maximum continuous charging: (1C 5A)
    Maximum continuous discharge: (3C 15A)
    Maximum instantaneous discharge: (5C 25A)
    Charging temperature (°C): -20~45
    Discharge temperature (°C): -20～60
    Storage temperature (°C): -20~35

But I guess I might need ( 16S-3P ) for a total of 18Ah to support a continuous discharge of 45 amps ?
 
Battery ready.

Battery LiFePO432650 3.2V 6Ah(6000mAh)
Maximum continuous discharge: (3C 15A)

16S-4P

This should give me 60A continuous and 100A instantaneous discharge, if my math is correct ?

So plenty of juice for motor at 42A / 48v = 2016watt

Could probably get a better controller and run it at 50A / 2880watt

Screenshot 2021-05-22 at 15.32.22.png
 
You must log in or register to reply here.

Similar threads

K
KHB - Suzuki skydrive 125 electric conversion
Replies
15
Views
3,404
kreal
K
Back
Top