Laptop Powered E-Bike

jm1

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Im curious if you will have success with those glass fuses and not suffer voltage drop across them under full load of the motor. I have the Bafang BBSHDwhich is supposed to limit to a 30A draw unless I modify it but Im still on the fence to fuse each cell or not due to fear of the voltage drop.
 

Korishan

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the voltage drop across the glass fuse would negligible.
 

Gyroman

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I'm enjoying this thread as I'm working on a very similar project. I've essentially builta 14s8p pack but configuredit as 2- 7s8p packs in series from recovered laptop cells. I tested all my cells to 2200mah+ plus but obviously didn't spend enough time considering resistance or c rating as I'm not getting the power from the pack and it warms up considerably after a bit. This was version 1.0 and I'm learning as I go.
 

rebelrider.mike

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Well, I finally saved up enough money to buy the motor... and then spent it on an ultralight backpacking tent instead. I really need the tent though. I think if I'm going to get this project done, I'm gonna have to settle for a cheaper motor:
https://www.ebay.com/itm/1000W-48V-...-Electric-Bicycle-Conversion-Kit/202404428608

Maybe you all might know of a better deal? I'm looking for a 26" front wheel direct drive motor. Ideally, 500W, 48V. No hurry though. It'll be another couple months of saving before I can try again. Gotta have priorities though. :)
 

ckvlbatteries

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Not really related to batteries ,but what tent did you get? My MSR Thunder Ridgehas treated me well through the years ,although a bit on the heavier side.
 

rebelrider.mike

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I bought a Nemo Hornet 2p. Half the weight of my old REI tent, which is a great tent. I've discovered though, that if I want to keep hiking, I've got to get my pack weight down.
 

Paul

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Feb 12, 2018
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Hallo, ich habe auch ein E-Bike gebaut. Es fhrt mit 80 Laptopzellen. Gesamt 600Wh. Ich habe auch darber gebloggt? Ist der Link von Interesse?

[diy] emanhs [/ diy]

[diy] frpwoq [/ diy]

[diy] jezhhv [/ diy]

Entschuldigung, ich habe Probleme beim Hochladen der Bilder.



[diy] ogdope [/ diy] [diy] pyfgvu [/ diy] [diy] arqadv [/ diy]


Ich kann keine Bilder hochladen ... Wie auch immer, hier ist der Link: http://pauls-werkstatt.blogspot.com/2018/10/ebike.html
 

Korishan

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Paul said:
Ich kann keine Bilder hochladen ... Wie auch immer, hier ist der Link: http://pauls-werkstatt.blogspot.com/2018/10/ebike.html

You can't upload any pictures because it is your first post. You should be able to go back and edit the post and re-add the images now, tho. You will have to do a full edit and remove the previous [ diy ] flags.
 

rebelrider.mike

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Thanks paul. I was able to read your writ-up from the link in your signature.

I'mswitching gears (no pun intended) and I've been looking into car alternators or starter motors as the motor for my ebike. Or maybe an old washing machine motor. Each would have it's technical challenges, but they'd all be way cheaper than any hub motor I could find. It is fun to work through technical challenges, but I wonder if the bike will work as well as it would with bolt-on parts.

I'll have to re-think the battery too. It will have to be made to accommodate whatever motor I end up using. Maybe I'll see if I can get some of alarmhookup's modem backup batteries. They may be able to tolerate a higher current than laptop cells. I'd have to change the title of the thread if I did that though, LOL.
 

rebelrider.mike

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Finally have a potential motor for the eBike! Along with a sprocket for the rear wheel.

image_ppnter.jpg


I'll have to figure out a way to make the two work together. As they are, they're not compatible. I've also made a purchase from BatteryHookup's website. Twenty Five batteries, or 100 cells total. These are modem backup cells, Samsung ICR18650-22Fand are rated for 4.4A continuous discharge. This way I'll need 60-100 cells for the eBike instead of the 200-300 laptop cells I would have needed.

And so, my testing station is back in service. Pay no attention to the red cells. They're not for this project. :)

image_twamig.jpg


I'm a little ignorant about some aspects of electric motors. This starter motor was designed to be used at something like 11-14V in a car, and use something like 400A I guess? I haven't found the exact specs yet. But that works out to 4,800W. At most, I'd be putting 1,600W and 140Ainto it if I use all 100 cells. I wonder if that will be enough to push the bike and I up hill? I'm also aware that starter motors are not designed to operate continuously. I wonder if there will be heat issues?. Maybe with the smaller Wattage, it won't be a problem. I've seen other eBikes using starter motors, so hopefully, mine will work out too. I also wonder if the Voltage could be increased to cut down on the Amps. I'll have to use some beaffy wires otherwise!
 

Korishan

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The only reason the 400A is turn over a motor that's under compression multiple times. Moving you and the bikes weight would be nothing in comparison to the torque needed.

Starter motors are not designed to run continuously, correct. However, you could probably cut some of the metal shell off, or, better yet, add some heatsink to it. That would help get rid of the heat. Mount it so that the air would blow over the heatsink while moving.
 

Geek

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Korishan said:
The only reason the 400A is turn over a motor that's under compression multiple times. Moving you and the bikes weight would be nothing in comparison to the torque needed.

Starter motors are not designed to run continuously, correct. However, you could probably cut some of the metal shell off, or, better yet, add some heatsink to it. That would help get rid of the heat. Mount it so that the air would blow over the heatsink while moving.

There are videos on YouTube that explain how to turn an alternator into an electric motor. And alternators are designed to run continuously.
 

Korishan

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An alternator is not a starter ;) I know alternators can run continuously. But he didn't say he was using an alt, but using a starter.

Now, if rebel mike can get an alt and convert it over, that'd be a far better option.
 

rebelrider.mike

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The time has been approaching to dismantle my original batteries that I build for the eBike. I suppose I got ahead of myself building the batteries before getting the motor. Since I'll be using a different motor, with different power requirements, these batteries are now useless, so the cells will be better off separated and ready to use for future projects.

image_twdcmc.jpg


I mentioned earlier that the modem cells I got from BatteryHookup.com are SamsungICR18650-22F. I went through my stash of good cells, and the cells recovered from the defunkt ebike batteries, and came up with an additional 27 identical to the ones from the modem batteries. Not quite done with testing, but it looks like I'll have 127 identical cells to work with for the new eBike battery.

image_shurpx.jpg


But I've learned my lesson: I won't be doing any soldering until I've got the actual motor installed on the bike. Especially as now I'm experimenting with unorthodox motors and won't know anything for sure until it's done.
 

rebelrider.mike

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Well, I ended up with 132 of the same type of cell, all of which passed testing! The best 128 will get used in the new battery.

I finally took some actual measurements to see what kind of space I've got available in the triangular space in the middle of the bike. Since I've changed my plans, as well as the cells I'm using, I want to put the battery in the triangular section. I got lengths and angles, and It looks like I can make the battery fit.

Here's the new idea as to how the components will go in the bike:

image_jbwaeh.jpg


I spent quite a while thinking of exactly how I want to wire things up. I want to use a PWM controller with a remote Potentiometer to control the current to the motor. I also want to use a momentary on switch to turn the motor on and off as I ride. Rather than routing the battery power to the handlebar and then to the motor, I plan to use a relay so I can put little wires to the on/off switch, and thick short wires from the battery to the motor.

Anyway, a diagram will probably make more sense than me writing about it:

image_oyesar.jpg


Each cell will have a fuse, and the battery willhave a fuse. I'll also be using a BMS. Not sure if the motor really needs it's own on/off switch, but I think I want to put a toggle switch somewhere.

I also made a lot of progress on the motor today. Maybe I'll make a video of it. More on that later...
 

Korishan

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Kewls!

I hope the little blue guy isn't an accurate depiction of the rider :p

Correct, you don't want to run the power wires up to the handle bars and then back to the motor. Not only is that a lot of extra wiring, but it'd also make steering a little more difficult as the wire would have to be 1 or 2 sizes larger for the double run to minimize losses. Large gauge wire doesn't like to flex all that well, and I doubt you'll use welding wiring for this project (altho, it wouldn't hurt, just be a little pricey)

For the momentary switch/relay, is that so you can get full power when you want without going through the controller? If not, I don't see why you'd have an extra switch. The controller should go 100% duty cycle on the PWM on full throttle.
You could just put the power button right on the battery pack, or right at the controller. It's not like you'd be operating the switch 10's of times a day like a delivery service (or are you?)
 

rebelrider.mike

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I decided to get back into video recording my projects. Nothing fancy or professional, but hopefully not too awful either.

Anyway, here is part 1 of the dirt cheap ebike project:

Korishan, to answer your question: I want a "dead man" switch on the handle bar to cut power to the motor the instant I take my hand away for whatever reason. I'm not sure yet if the starter motor will work for me, but whatever motor I use, I'm hoping that I can pedal more often than being dependent on the motor. It's all just ideas for now.
 

Korishan

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Ohhh, ok. Now the "dead-man" switch I understand. Like one of those keys that are fastened to your wrist/ankle on snowboarders and jetskis. Got it! :)

You did a pretty good job on the video. Only issue I saw, well more like heard, was that the sound was too low. Even having my volume boosted and turned up, I had a hard time hearing you. If you use your cell phone to do the recording, see about getting a bluetooth headset and record your audio that way. That's how I do mine most of the time and the sound is super clear.
 

rebelrider.mike

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Thanks Korishan,
I boosted the volume while editing, but I'll have to boost it more. I guess part of the problem is my computer volume is super loud. I keep the volume around 5-10% and I still often have to turn the volume on YouTube down when I watch.I'll keep it in mind for future videos.

In the meantime, here is a second installment:

Jury's still out on whether this motor will even work, but I still give it a solid "maybe", LOL.
 

Korishan

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Another video! Startin to crank them out ;)

The audio is still really low. Maybe you should test the audio on your cell before making the video live. That way you can hear the actual volume. I have Harmon Kardon powered speakers, a Volume Booster extension for Chrome. I still had to turn YT audio to 100%, system volume to 100% to hear things clearly.

That massive heatsink you have will work great. Especially if you were able to mount the motor so that it was parallel to the bike (this would make needing a spider gear to drive the bike, tho)

With the springs on rotor, you should probably leave them alone. Less contact means more potential for spark which will burn up the commutator and brushes faster. The heat would be better to deal with than having to replace the commutator contact pads. IMHO

As for the bearings, I would recommend upgrading them to high output bearings. Remember, the original design of the starter was for minimal use. Maybe the entire life time of a starter, the bearings would be engaged for about 5 seconds at a time, and average 6 times a day. If we figure 6 days a week, that comes to about 180 - 200 seconds per week, or 9,360 seconds a year. This would be a total 156 hours of run time. This isn't much in the life of a standard bearing. However, see if you can find the numbers stamped on the bearings you have to see what grade they are.
 
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