My electric bikes & projects
 

Thought I'd start a thread, since there seems to be no end to my electric scooter/bikes. They tend to come to me in various states of distress, and those which don't, end up in such a state pretty quick. ;)

Really, I love battery-electric powered doo-dads that do something useful and enjoy working on them, and I like the freedom of riding without a cabin/cage around me, so it's no wonder I keep coming back to these and jump on any good deals that come my way.

Let's start with my original, a Luyuan electric scooter(that conforms to Canadian electric bicycle laws) sold around hear a decade ago as a "Green World EV":

http://photoshare.shaw.ca/image/b/2/...nscooter-0.jpg

...complete with my kid, when she was 3 years old. That was a while back. That's one of those child carrier seats, and I built the bar it sat upon, so she would be in the safest spot. She and I, or she and my wife, rode around four a couple of years like that, until she outgrew the seat.

Bike was neglected. Batteries were pretty weak, but it was a starting point.
The 48v, 350w motor went nicely, until you got on an above-average incline, then it would grind to a halt. Wasn't long before I modified the controller to permit more current. It worked quite well, but the already weak batteries didn't survive long. I would still use it for short trips, but the range was non existent after that.

I don't seem to have any older pics of my second one, that came a few months after the first. It's current state can be seen here beside the blue one, where they currently sit "decommissioned":

http://photoshare.shaw.ca/image/b/2/...kes00001-0.jpg

I traded a motorcycle that I got on the cheap for it and fixed up, when the carbs on said motorcycle started acting up again and I got fed up with it...

It too is a Luyuan/GWEV, but has a 500w motor on it instead. It had good batteries, and since the bike was identical in all but running gear, the battery fit the blue bike as well. Hence how I got a couple of years out of the blue bike. If I went with my daughter, we'd take the (slower) blue bike. And if I was going out on my own, I'd take the more powerful black & silver.

Being greedy or some such, I tried modifying the controller for the black one, but at some point I screwed up and fried it. I recall shorting something out on the board with a screwdriver or a screw or something when testing it out after, and I probably fried the 5V bus. One year, I'll get around to trying to fixing it.

Instead, I dropped a new 1500w, 72v ebay controller in to it and had fun getting the phase/hall wiring right and rewiring the bike with heavier wiring and a switch setup for dual voltage - 72v & 48v, because it would go illegally fast on the road at 72v. It did about 45km/hr on level or slight inclines, and more with a downward incline. It was fun, but I only got a couple of uses out of it before the battery selection switch fried. Apparently, they're not built to withstand the intense discharge of all those capacitors in the bigger controller when dropping from 72v down to 48. :rolleyes:

I replaced the switch, figuring I'd just be more careful/give the capacitors time to self-discharge before switching, until I felt like adding some minor circuitry to prevent it. Well, the new switch didn't hold up well to the large current flowing through it, and also died within a couple of rides. It was late in the season, so I just packed it away and satisfied myself with the blue one instead.

I mentioned rewiring it. This was the instrument cluster I put together when I did that:

http://photoshare.shaw.ca/image/b/2/...kes00002-0.jpg

Active voltage, current (100a shunt mounted under the leg shield), and a much more accurate speedo...since the new controller didn't have a speed output to run the old, inaccurate one. And it didn't go high enough, either.

It was nice to see exactly how much power was being sucked out of the batteries, which was up to 40 odd amps. The motor got luke-warm to the touch after a while, but that was it. Lost regen braking with the cheap controller, mind you, so slowing/stopping became pretty hairy.

As a side note, for those who don't know...you can trick one of these motor controllers in to powering on in spite of being above or below it's operating voltage range by having a different voltage going to the power(on/off) then is going to the main battery input for the controller. IE, the controller circuitry was seeing ~72v, even though I was only feeding 48v through the controller to the motor. (if the FETs and capacitors were rated high enough, this could mean feeding 84v or 96v through the controller while the control circuitry only sees 72v)

Some day, I'll come back to this bike and/or re-purpose the motor. I doubt it compares well to modern ones, but it was certainly powerful and fast enough for my purposes.

That will do for the first post... :snail:

I got the chance to ride a small Pit Bike with an Etek motor and Prius batteries. It had squarish wheels. I mustered the courage to go full throttle to the geared top speed of ~40-45mph and it scared the crap out of me. I now realize it had the power of a real motorcycle and i should not have been allowed to ride it. But boy did i get an EV grin!

Laste year, I picked up a bunch of B-grade A123 20ah LiFePO4 cells off of ebay, and painstakingly built a "48v" battery...

http://photoshare.shaw.ca/image/b/2/...trike002-0.jpg

http://photoshare.shaw.ca/image/b/2/...trike001-0.jpg

http://photoshare.shaw.ca/image/b/2/...trike003-0.jpg

http://photoshare.shaw.ca/image/b/2/...trike004-0.jpg

After some issues with my own ignorance and then issues with the BMS I had, I had to replaced cells as often as I used it. I've got it under control now, but I no longer have enough cells to make a second such battery.

This was how it looked:
http://photoshare.shaw.ca/image/b/2/...han00001-0.jpg

I added further protection, in the form of low-voltage alarms made for RC batteries:

http://photoshare.shaw.ca/image/b/2/...ion00064-0.jpg

This is how it looks now:

http://photoshare.shaw.ca/image/b/2/...kes00004-0.jpg

It's trouble free at the moment, and it makes audible noise if any cell drop below 3V, so if I accidentally leave my ebike turned on again for some reason, I have a chance of preventing damage...

Specs: 20ah @ ~52V. BMS supposed limit: 100a peak, 50a continuous. I can get 30-40 km on a charge on my current e-bike, running at full speed, with a small passenger. :thumbup:

Wow! The battery build here is impressive (love the pic of the "small passenger" too). How did the battery do over these last 8 months? How much do you think you spent trying to build it? My 14ahr 36 volt set up cost about $500 for the battery alone.

Great project and good job) Powerful battery, cool! I'm in the process of creating my e-bike kind of EGO BIKE 26” Fat Bike) I hope to get something out of it:rolleyes:

All the thread photos are dead :(

Yeah. I want to know what so impressive about the battery build

Nothing impressive about the battery build. The A123 20ah cells are stupidly powerful(high amperage) though.

So what's happening with this bike these days? You are riding it?

I have it. Not riding it much. Kiddo has grown to the point of wanting to ride her own bike, so we're using old-fashioned leg power this season. I just took her for her first motorcycle ride on the weekend, so she's still getting rides...just faster ones.

Awesome. Kid on a motorbike. If you can get them on early and loving it, sooner or later they'll want her own motor.

She's 9 and is already saving her pocket money to buy a car like my purple firefly when she's old enough. Meaning she's already picking up on my same interests and enthusiasm towards them.

Of course, she gets distracted and buys other things now and then. ;)

I slapped together a pedal generator this morning, using an old exercise bike that I bought for this eventual purpose, and a treadmill motor I bought on the weekend for such experimental purposes.

http://ecomodder.com/forum/attachmen...1&d=1509475289

Friction drive, with the tire rubbing against the flywheel of the motor. Its a 130v permanent magnet motor, runs at about 400 rpm off of 12 volts, so it just happens that running friction drive against the tire gives you probably 500 rpm at a steady cycling speed.

I put a load on it (100w inverter, and a sub 100w fan), and a diode to prevent the battery from running the motor, and tested it to see how hard it was to keep the battery voltage steady.

http://ecomodder.com/forum/attachmen...1&d=1509475304

That steady, easy pedaling speed would put out about 4 amps and hold the voltage around 12.6v. I'm out of shape, but if I got going fast enough, I could get it up past 14v, and about 8 amps.

It took a bit of screwing around, and my lungs got a good workout...but maybe now that I've combined a "doohickie" with exercise, I might be inclined to get some. :P

https://youtu.be/S4O5voOCqAQ
Olympic Cyclist Vs. Toaster: Can He Power It?

Dude's legs are nearly as thick as my waist!

All that to generate just a bit less than one horsepower. :eek:

So much energy we use that we take for granted like a tank of fuel in a car for $30. How many people would it take to push a car uphill through the snow for 200 miles and how long would it take and how much would you have to pay them?
.
Man made is a misnomer. Everything you see around you that is "man made" is really made from huge amounts of super cheap fossil fuel energy. And a small amount of raw materials that were harvested and processed with huge amounts of fossil fuel energy.

So I 'll stick to making toast on an wood fire;)

Doesn't a gallon of gas contain 31,500 Calories? Someone calculated that walking gets 400 MPG.

I'd rather drink apple juice than gasoline. Riding a velomobile is even more efficient.

Been thinking I need to stop screwing around with cheap, basically broken crap, in general, and start replacing it with "something nice".

That being said, I've been vaguely looking out for a Giant hybrid bicycle - I used to own a half decent one, and it was a great machine - with thoughts of making it electric. My classified searching came up with a "barely used" one that came factory electric, with dead batteries, that was about the kind of price I figured I'd have to pay for a non-electric Giant hybrid. A few emails and a drive later, I brought her home:

http://ecomodder.com/forum/attachmen...1&d=1518337204

I'll see if I can revive the batteries this weekend. And, if not, well, it was still worth the price, even if I have to buy new cells for it. :)

Right now in New York state all electric bikes are expressly illegal and are being fined and confiscated in NYC. But there is legislation sitting in commitee that will legalize Class 1 pedal assist bikes as they are well known in Europe for many years and bring the legislation into line with what California and D.C. have already done which is to say that a class 1 e-bike is still a bike. Not a moped or motorcycle. Contact your state legislators to get all states onboard with legal e-bikes.
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https://peopleforbikes.org/
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They're perfectly legal here. Up to 500-watts. Have been as far back as they've been selling cheap chinese ones, 15+ years ago. There are some other stipulations, like needing a seat and pedals, but that's the extent of it. My other one is shaped the same as a 50cc scooter(moped, as some of you call 'em), except it has pedals, so it's legally an electric bike!

Back on topic...batteries don't appear to be completely dead. Self-discharged beyond what's safe...I'm trickle charging them at something stupidly low(safe?), ~1 watt, with a "dumb" charger. Either the charger they come with doesn't know how to deal with over-discharged batteries, or else the BMS is blocking them from charging. Probably a good thing, since who knows what will happen if you put full charging current in to a "dead" battery.

http://ecomodder.com/forum/attachmen...1&d=1518418111

The first one has come up and stayed up. I briefly tested that the charger that came with them is now willing to charge them, but only for a few seconds. I want to bring them up gently. The second one has just started it's slow recovery. Fingers crossed, they come back to life and still retain reasonable capacity. I don't think I want to have to try and replace the cells, the way they're basically "woven" together by the bus-bars!

OooOOooh....it's a nice ride, even without electric assist. I can keep up with my kid again! ;)

Battery charged up without complaint. Cells perfectly balanced. Bike powered up and works. Battery didn't complain with a heavy load put on it. All is looking well at this point!

It took a good 90% of full amp-hours to charge the battery, with very little heat given off by the cells. Promising. Proper battery capacity/load testing will commence tonight.

http://ecomodder.com/forum/attachmen...1&d=1518608418

Full capacity!! :eek:

:cool:

:D

Bike works flawlessly. I move on it like I was 20 and in shape again! ;)

Loving this little guy right now:

http://ecomodder.com/forum/attachmen...1&d=1519073265

It's a digital DC-DC converter / Power supply -- give it power, from a battery or a fixed DC power supply, and set it to whatever voltage and current combination you want. Up to 60v DC in, up to 120v DC out, up to 15A in or out.

In the photo, I was charging a "nonoperational" 18v lithium cordless power tool pack. It was being powered by a 12v/5a power supply I have a few of. Set the final charging voltage, set the maximum current I wanted to charge at (output watts equal or less than input, of course), and just let it do it's thing.

I didn't trust it's accuracy at first, but after confirming that it was stupidly accurate (identical current and voltage readings as my best DVM), I decided I could trust it. Which is a relief...especially when dealing with lithium cells!

Lithium...my new-to-me hybrid bike has given me new appreciation for it. And I've been learning a fair bit about it. But that's a topic for another time...

I've been mostly tidying up my shop...I'm one messy pup when I get working on things. It was something to do while keeping an eye on charging batteries and staying in out of the cold...

I cooked the 24v SLA charger I was using, somehow. It survived charging the ebike batteries (though it required adding a bunch of resistance to slow it down and not overload it), and then went out on something else in spite of all the resistance I had in to slow it down. Go figure?

Took it apart this morn. Not the first charger like this I've "cooked". Found what I was looking for pretty quick...

http://ecomodder.com/forum/attachmen...1&d=1519243525

http://ecomodder.com/forum/attachmen...1&d=1519243534

That was a 1 ohm resistor. Seeing as I had bought two when I fixed the other charger, I still had one hanging around. Easy fix.

Adjusted the output voltage as well. It was too low for my liking...

http://ecomodder.com/forum/attachmen...1&d=1519243543

Might help keep the batteries healthier. Probably wishful thinking. But hey, while I was in there, why not?

I shouldn't be frying any more, seeing as I rediscovered my programmable power supply. It can give me exactly the voltage and current I want to output to a battery of just about any voltage. :p

Where did you get said little guy?

Ebay. They're about $25. Search for "120v DC-DC converter 900w" and dozens should pop up.

Another cool thread. I just replace my bike charger. But first I investigated. The insides were mostly greek to me. I want to learn though. I'd also love to learn how to safetly adjust voltage. I have a 12s lithium battery. Most of the cheaper chargers are about 1.5 volts below what I need because they are for 10s lithium.

Look for a mini "pot" (potentiometer, in other words a variable resistor), usually near the output wires. Turn it one way or the other with a small screwdriver. Look like this, though maybe only 1/4" or smaller across:

http://www.faranux.com/wp-content/up...e-resistor.jpg

You might "cook" the charger like I did, mind you, as you can probably expect a lithium battery to suck down the amps faster than a cheap lead-acid charger will want to put out. Might not too. Should be OK with one meant for lithium.

You can probably get away with one made for slightly higher voltage, seeing as your BMS should determine when it's time to cut off the power. (Err...do this at your own risk, mind you!)

Never mind on most of that; found your thread again!

My luck...not only has it been too cold to ride, it dang well snowed!

It never snows here. Ok, rarely. We get a couple of inches once or twice a year. Usually by this late in February, it's 10 above or more and all the trees are in full bloom.

If this is what mother nature is going to do when I get an eco-friendly ride, maybe I need to go dance naked around a tire fire to offset it!

Oh, hey...it looks like I never continued my story from the first post. Ha! Only took a couple of years to notice.

About to and a half years back, I bought another fixer-upper ebike. Bit better quality than the ones I originally had. Bigger batteries, more power. As she was when I picked her up:

http://ecomodder.com/forum/attachmen...1&d=1519329823

Dead batteries, flat rear tire, plus a year or more weathering to undo, which meant taking apart all the switches and cleaning the contacts as well as cleaning and removing rust. She's been a faithful ride ever since.

http://ecomodder.com/forum/attachmen...1&d=1519330110

And here's trouble brewing:

http://ecomodder.com/forum/attachmen...1&d=1519330245

This is the "bike" I was referring to "still riding around" in earlier posts. It ran well with my LiFePO4 pack for a while, but I lost another cell or two, and it got shelved, as I was out of replacements. Expensive learning experience! I've recently(if 3 months ago is recent) built it a brick of healthy used lithium batteries. For now I'm still using their original BMSs and charging each of the 5 packs off its own charger, as I trust their BMSs.

Brick:

http://ecomodder.com/forum/attachmen...1&d=1519331002

Plenty of room where the big old 20ah SLA's were: (Still room for one more of the packs it's built from)

http://ecomodder.com/forum/attachmen...1&d=1519331023

I also "upgraded" the controller. Somewhat unnecessarily. I was trying to give the "bike" regen braking. Turns out that "EBS" (electronic assist braking) is not the same as regen braking. :o In fact, I have no idea what it is because it doesn't seem to make a difference.

I did get more power out of it - it's a 40 amp controller vs maybe 27...? - so it has a lot more gusto. The controller is also rated up to 64v...which is good, since the nominal voltage of my pack is 55 and the full-charge voltage is 63. (which is what the capacitors inside it are rated for, so no going higher yet).

I still need to test the actual capacity of said brick, but expect to have 1.25kwh based on the tests already done on some of the cells. Maybe that will be a project for tomorrow...

Regenerative braking is when the motor is used as a generator to charge the battery. Dynamic braking is when the armature terminals are connected so the motion creates a current and magnetic field that works against the magnetic field from the field coils. It does not lock the wheel.

And EBS is neither!

Continuing my current obsession with lithium-ion batteries, I wanted to know more specifically what kind of capacity I would get out of my "bricks" in my electric scooter "bike"...

Finding a test load was a bit of an annoyance. At least one with any significant current draw. I started with an inverter to run something on AC, but the low voltage shut-off on it kicked in half way through. So I boosted the output, but that was a PITA and flaky. I needed something simple and reliable. And I had a box full of incandescent 12v bulbs from switching over a few cars to LEDs, so this was my setup:

http://ecomodder.com/forum/attachmen...1&d=1519534312

I remembered making something similar as a kid for much smaller bulbs. Nothing to it but a 1x4 with 5/8" holes and two pieces of aluminum foil:

http://ecomodder.com/forum/attachmen...1&d=1519534322

Good for burning off 10 amps! (and doesn't care if the voltage drops, either)

So far, I've been getting a good 21AH out of each of the smaller bricks that makes the bigger brick:

http://ecomodder.com/forum/attachmen...1&d=1519534333

That's actual, usable amp-hours, under load and going through the BMS for both charging cut-off and low-voltage discharge cut-off. Cells settled around 4.15v after charging (a touch low), and low voltage cutoff was a hair below 3v.

Temperature makes a fair bit of difference too, according to the data sheet for the cells. And its fairly chill in my work shop.

I'm fairly pleased with the results. 21ah under a decent load totally blows away lead-acid, and the battery weighs 1/3rd as much.

Do I want more lithium batteries?

No, nevermind...that's a given! :p

Do I need more? That's the real question. :confused:

I haven't even settled on what to do with some of the ones I have! :rolleyes:

Took the hybrid for a real ride today. (It was decently above freezing at last)

http://ecomodder.com/forum/attachmen...1&d=1519673664

18km!

Ok, that might not sound like much compared to people who are used to it, but it's probably twice what I could do without assistance. And I probably would have ruptured something trying! :o

Batteries were at 28.3v (I used 2 bars, so about 25%) and 27.1v (it had 2 bars left at one point).

Don't know how accurate that LED display is, since when I turned it off or switched to the other battery, it showed full or almost full again. The same battery that was showing only 2 before was showing only 2 used when I got home...

But rough estimate based on voltage...the first used about 15% and the second used 50% of capacity(those numbers could be out to lunch since I am looking at a generic voltage vs capacity chart). 65% of 9ah, 152 watt-hours, ~8.5 wh/km.

:thumbup:

I won't know without using my AH meter to check how much it take to recharge the batteries (too late, this round), but that should be in ball park range. That's right around 1/3rd what my all-electric powered electric scooter/bike runs at.

The real point though is that I got an hour of decent exercise without killing myself, and felt productive doing so. This should make for a pleasant pass-time in the spring and summer!

PS: I just realized that's farther than I "commute" to work!

PPS: Theoretical range of 55km between both batteries.

Stiff an sore! :(

Everywhere but my legs!? :confused: