Genesis V2100 72V overvolted build log

[Baron]

I have been building simple e-bikes since last winter using a 48V 1000W kit from ebay, namely this one: http://www.ebay.com/itm/48V1000W-26...-Conversion-/371289491857?hash=item5672940991

This will be the third bike I strap this kit to, however this time I want to try feeding it more voltage. This is the controller I will be using: http://www.aliexpress.com/item/Free...-s-Electric-Bicycle-Controller/499889986.html
It arrived a few days ago, I asked Leo to configure it for 72V, 30A max, 70V cutoff. Hall/phase combinations have been a pita to test. More info on the controller and wiring in the next post.

I will be using these batteries in 20S2P: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=58976
The batteries arrived last week and I have been busy balancing and testing them with my 48V kit to make sure there are no duds. So far so good, just waiting for more 4mm bullet connectors in the mail so I can wire up some harnesses.

It will be interesting to see how the 1000W motor will react to being fed ~2400 peak watts. At the minimum it will probably require beefing up the phase wires, maybe even some motor ventilation mods. But, that's the point of this build log!

 

[Baron]

I picked up a dirt cheap Genesis V2100 from craigslist. These are decent bikes for e-bike conversions as you can see in these builds:
https://endless-sphere.com/forums/viewtopic.php?f=31&t=66978&hilit=Genesis+V2100
https://endless-sphere.com/forums/viewtopic.php?f=6&t=62159
https://endless-sphere.com/forums/viewtopic.php?f=6&t=36437
https://endless-sphere.com/forums/viewtopic.php?f=2&t=35301
https://endless-sphere.com/forums/viewtopic.php?f=3&t=68436&p=1053851&hilit=Genesis+V2100#p1053851

^Those builds were largely my inspiration for getting a genesis and creating this build. I wanted something with full suspension and disc brakes on the cheap, and the genesis fit the bill. Many people report that the bike is worth the price of admission for the frame/swingarm/pivot arm alone, and the rest of the components are garbage. I would have to agree.



^Pics of the bike after just getting it. It was in rough shape, tires were shot, handlebars bent, no seat, nothing set up. Note the bright lime-green paint job. I actually thought it looked good but the colors were so faded from sitting in the sun that I decided to paint it. 2nd pic is after I got it fixed up and rideable. Initial impressions: the suspension is terrible, but at least the brakes are good once you tune them. I like the brake/shifter combo, I think they will make it into the final build.

 

[Baron]

Painting the frame. I used a razor blade to remove the stickers, then sanded the frame to rough it up so new paint would stick. Didn't have tools on hand to remove the crank and swingarm so I just painted around them. A couple coats of primer, then matte black (used pretty much a whole can), then clear.




View attachment 3


^Test fit with the triangle frame bag I'll be using to hold my batteries. Also replaced the fork with a manitou spyder, it's an older fork but definitely an upgrade from the stock genesis fork.

 

[Baron]

Fitting the torque arm. I think this is the best configuration, considering it wouldn't be possible to clamp to the upper part of the frame that moves a little bit when the rear suspension is active. If anyone knows a better way to mount this torque arm to a v2100 frame, let me know

 

[Baron]

These pics are the bike set up with the 48V kit. I could easily fit 3-6 batteries in the triangle bag to test the bike out with 12S. I've since replaced the clip pedals for aluminum ones since clips don't help much on an electric bike. The rear shock has been upgraded to a dnm dv-22 which is a slight upgrade from the stock genesis shock. Tomorrow I'll be picking up a Fox Vanilla R rear shock from a guy on craigslist. It's 8" eye to eye, but I think that should just barely work in this frame. Or is it too long?

I'm still sorting out the new 72V controller so it's not installed yet, but expect some new updates in the next week after I get my bullet connectors in the mail.

edit: some info I forgot to mention. the frame bag is an Ibera triangle bag (large) http://www.amazon.com/gp/product/B00H55I8J8?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s01 and I have upgraded the freewheel to a 7-speed with 11t on the smallest cog.

 

[Baron]

greentime(?) controller

installed it and went for a test ride the other day. conclusion: me go fast now
i was hitting 44mph on a slight downward grade. just testing top speed and heat build up on a 1/8 mile secluded road. I most definitely need to cool this motor as it became way too hot, just placing my hand on the motor shell I could feel it, and the phase wires were pretty hot too. I am definitely air-cooling this motor and upgrading the wires. I'll be drilling holes in the hub motor and using some insulating varnish http://www.ebay.com/itm/221519695337?_trksid=p2057872.m2749.l2649&ssPageName=STRK:MEBIDX:IT on the inside.

This is my first time opening up a hub motor myself but I have lurked and read a lot about the procedure here on e-s. if anyone has any tips for me please feel free to add them here.

 

[Ellou]

How does the stock swing arm hold up on these? Most of the builds used the farfle swing arm no longer produced. Just curious if I should pic up a cheap donor off CG for a later build. It's a like new one for 80 now but could probably get it cheaper.

Also what's your hieght? I'm 6ft and wondering how small of a bike it really is. I know you don't pedal much but if I had to I wouldn't want to be cramped.

 

[Baron]

How does the stock swing arm hold up on these? Most of the builds used the farfle swing arm no longer produced. Just curious if I should pic up a cheap donor off CG for a later build. It's a like new one for 80 now but could probably get it cheaper.

Also what's your hieght? I'm 6ft and wondering how small of a bike it really is. I know you don't pedal much but if I had to I wouldn't want to be cramped.

regarding the swing arm - it's a pretty standard aluminum swing arm with 135mm dropout width. I wish the dropouts were deeper but the torque arm holds my motor solidly in place. I believe people who where upgrading to a farfle were doing it for the increased length, wider dropout width, stronger construction, etc. You could fit a wider motor like the mxus v2 in the farfle. I would really like to get my hands on a farfle swing arm or similar for a future high-powered build.

I am 5'11" with long arms and the bike fits me okay. With the seat at the height you can see in the pictures, my legs are almost straight when fully extended. I actually try to pedal as much as possible to get a little workout in. I forgot to mention above but I have upgraded the stock freewheel that came with the 48V kit to a 7-speed freewheel with 11t on the smallest cog. Along with the 48t up front, this lets me pedal up to 30mph.

 

[Ellou]

Ok. Thanks. I didn't understand what you meant about how many batteries the bag would hold. I was looking at that bag on ebay. I'm planning on using the multistar 6s 16ah. Do you think it would fit 2 with the 48v controller?

Is 30mph without pedaling realistic on a 1000w? I don't want to go that speed all the time but when I go camping it be nice to do some speed runs.

 

[Baron]

Ok. Thanks. I didn't understand what you meant about how many batteries the bag would hold. I was looking at that bag on ebay. I'm planning on using the multistar 6s 16ah. Do you think it would fit 2 with the 48v controller?

Is 30mph without pedaling realistic on a 1000w? I don't want to go that speed all the time but when I go camping it be nice to do some speed runs.

With the stock 48v 1000w kit and 13S li-ion I was getting around 28 mph on flat ground without pedalling.

The bag measures 16" x 17" x 11" according to amazon and my testing shows it can stretch to around 3-4" wide in the central area of the bag. I can't recommend putting your controller in the bag, especially with such limited space.

Update on this build: I've been road testing this controller a bit. Tonight I wired up a voltmeter/ammeter to my handlebars to monitor battery voltage and motor amps. Well it turns out the amps were as high as 45-50 for short burst when I was accelerating. With my 20s lipos (74V nominal) this is roughly 3700-4000w. I really don't think this motor can handle 4kw lol. I asked the seller to configure the controller for max 30A so this was unexpected. I'm still going to do the cooling mods/phase wire upgrades to the motor, I just won't push it as hard now knowing that its peaking at 4kw. i should probably install a temp sensor in the motor, been lurking this thread for ideas https://endless-sphere.com/forums/viewtopic.php?f=1&t=25502

 

[Baron]

It turns out one of my hall sensor wires was completely shredded inside the axle. That explains why it felt like the controller was running sensorless. I did a whole bunch of hall/phase wire combination testing but all that amounted to was telling me something was broken in either my controller or motor.

I opened up my motor using this guide https://endless-sphere.com/forums/viewtopic.php?f=14&t=30211&p=436758

Replaced the old phase wires which were around 15awg. First I tried getting 10awg through the axle but they were too big even with shrink wrap as insulation, so I settled for 12awg.

I have all the halls soldered, taped, and heatshrinked as you can see in the pics. I even added an extra wire (brown) for a future temperature sensor inside the hub. Still left to do: solder the phase wires inside hub, solder 10awg phase wires outside the motor to connect to the controller, test that everything works, drill holes in the motor covers, spray insulating varnish on the hub internals. I also have a new wattmeter and moped mirrors to install.



View attachment 2

 

[Baron]

can anyone help me with installing a temperature sensor in my hub? this thread https://endless-sphere.com/forums/viewtopic.php?f=1&t=25502 says I should get a 10K NTC thermistor. I would like it to be compatible with a cycle analyst 3.0, which I will eventually be getting, or in the meantime be able to read temperatures through some other means like a voltmeter or ohm reader? can someone help me find one for my build? preferably from ebay

http://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=10K+NTC+thermistor&_sacat=0

more pics of the hub opened up:







View attachment 1

 

[Ellou]

Not sure if this will help you but this is a link I saved for installing a temp sensor.
https://sites.google.com/site/shelbyelectro/motors/mods/installing-a-temp-sensor-in-a-hub-motor

 

[Baron]

Not sure if this will help you but this is a link I saved for installing a temp sensor.
https://sites.google.com/site/shelbyelectro/motors/mods/installing-a-temp-sensor-in-a-hub-motor

Thanks but I'm looking for something compatible with a cycle analyst. Need to find a 10k NTC thermistor apparently, just need to choose the right one.

 

[Baron]

Update to the build: efficiency is pretty terrible. I did a road test for WOT, it gets up to 3000W accelerating to top speed which is around 40-45mph, and it only tapers off to 2500W at cruising speed. While I don't maintain this top speed for more than 10 seconds at a time, I can't imagine it being very efficient at lower speeds either. It's really fun going 45 but it's sucking the battery dry. I think I need to go to a smaller diameter wheel or lower the voltage down to something like 16S or 12S. That should take a huge load off the motor.

The good news is that it doesn't heat up as much as before. The cooling mods are doing work. But I didn't stress test it very hard yet. I don't have a temp sensor in the motor so I'm wary of smoking it. I do have an unused wire in there waiting to solder to a temp sensor tho. I realize these cooling mods are overkill for a motor of this class but it's really more than enough power for me.

i want to get tubeless tires and disc brakes for better safety at high speeds

moar pics:

View attachment 5

View attachment 3

 

[Baron]

my 72v 1500w greentime controller seems to be stuck in sensorless mode. every combination of halls/phase either results in a forward or backward rotation. for example, for a static set of halls, the 6 combinations of phase wires result in 3 forward and 3 reverse. this holds true for every static hall combination. i have confirmed that the motor isn't the problem, the halls were damaged inside the motor axle but i fixed them and the sensorless problem remains. i tested the motor with my old 48v controller and confirmed that it works properly in sensored mode. i don't know what the problem is with the greentime controller but perhaps it's stuck on some kind of "self-learn" mode. i've skimmed through the greentime controller thread to no avail https://endless-sphere.com/forums/viewtopic.php?f=30&t=40900&start=850

 

[Baron]

so until i figure out how to fix the 72v controller, i am experimenting with my old 48V controller. info on that controller can be found here: https://endless-sphere.com/forums/viewtopic.php?f=3&t=72201&p=1089925#p1089925
i am testing the effects of running more cells in series, as well as shunt mods to increase the max current. 16s might be too much for the controller (caps are rated 63v) but i'm running it anyway b/c i really don't care if it breaks.

rough calculations for my motor:
12S = 48V = 480.00 rpm = 37.00 mph in 26"" wheel no-load = 31.00 mph in 17" moped rim no-load = 28 mph cruising speed WOT in 26" wheel = 600-900W cruising speed WOT = 23.45 mph 17" moped rim (?)
16S = 64V = 559.13 rpm = 43.10 mph in 26"" wheel no-load = 36.11 mph in 17" moped rim no-load = 32-35 mph cruising speed WOT in 26" wheel = 1300-1400W cruising speed WOT = 27.64 mph 17" moped rim (?)
20S = 80V = 651.30 rpm (?) = 50.21 mph in 26"" wheel no-load (?) = 42.07 mph in 17" moped rim no-load (?) = 40-45 mph cruising speed (with 40A controller) in 26" wheel = 2500-3000W cruising speed WOT = 35.18 mph 17 moped (?)

the figures marked with a (?) are educated guesses based on the rest of the info. so the setup i am aiming for is either 16s in a 26" wheel or 20s in a moped rim to get the speed i want. i don't really like 20s on my 26" wheel with the 72v controller but reducing the size to something like a 17" moped rim with tire (about 21" total diameter) would be a better combination. a smaller wheel would improve torque, efficicency, lower heat, and i'm ok with the reduction in top speed. 45mph is way too fast for my bike anyway. if i had disc brakes, tubeless tires, a longer wheelbase, and a lower center of mass, then maybe it would make sense. but until then, i'll probably be running 16s @ 40A max on my 26" wheel with the 48V controller.

The only thing i have to solve for in my 16s setup is the lvc. right now my only lvc is the wattmeter that i have strapped to my handlebars, you can set an alarm to go off when a certain voltage is reached. range is 0-100V. when i ride with 16s, i set the alarm to go off at 56V so i know when my lipos reach 3.5V per cell. the only problem is, the alarm is simply the wattmeter's backlight flashing, I can't see the alarm in the daytime, only at night.

 

[Ellou]

I don't know which watt meter you have but my suggestion would be piezu buzzer. Open up the watt meter and solder the buzzer to the flashing led. (If it's a separate set of wires that make it flash. You could also use the lvc beeping connectors that go on the balance plugs. There small, cheap, accurate and loud as hell.

Please report back about the 16s setup. I have the same kit and would like to see how it works out.

 

[Baron]

I don't know which watt meter you have but my suggestion would be piezu buzzer. Open up the watt meter and solder the buzzer to the flashing led. (If it's a separate set of wires that make it flash. You could also use the lvc beeping connectors that go on the balance plugs. There small, cheap, accurate and loud as hell.

Please report back about the 16s setup. I have the same kit and would like to see how it works out.

The piezu buzzer just makes noise when the led is active? That could be useful, but it would also mean I couldn't always have the backlight on at night..
What do you mean by "the lvc beeping connectors that go on the balance plugs." An alarm that plugs into lipo balance charge wires? Got a link?

My wattmeter is this. It's kinda like a mini cycle analyst. It's one of the only ones on ebay I could find that did over 60V. I really dig it. It runs off the bike's main batteries, I mounted it to my handlebars with zip ties

I've done some road tests with 16s but note that i've done a shunt mod to the stock 48V controller. It draws around 33A peak now instead of 25A. Not a big improvement, barely noticeable actually but I'm still playing around with the shunt mod to get more amps. Aiming for around 40A which is the max rated for that controller. The shunt mod only seems to effect acceleration from a stop, I haven't noticed much higher amps under other riding conditions.

I'm basically riding around at WOT to test speed and heat buildup. I'm only going around 7-10 miles at a time. Speeds are something like 33 mph on flat ground, 24-28 mph uphill 37mph downhill. Uses about 1800W peak and around 1400-1600W cruising. I think this well within the realm of safety for my vented motor. The motor is rated to do 1000W all day long, but I've read here that people have pushed 72V 40A into this motor for around 10 miles without burning it up.

 

[Ellou]

http://www.hobbyking.com/hobbyking/store/__74024__HobbyKing_8482_Lipo_Voltage_Checker_2S_8S_.html

This connects to the balance lead of your lipo. Some you can set to a specific voltage and when the first cell dips below say 3.5. Loud beeping. I mean really loud I use them on my planes sometimes and hete them clear as day from 1000ft. Downside you need one for each pack. Plus side there cheap but work good. I'm coming from an rc background so some of my ideas won't cross over to e bikes.

I think I'm going to have to sell my v2100 though. I can't find a good mounting option for my batteries.

 

[Baron]

http://www.hobbyking.com/hobbyking/store/__74024__HobbyKing_8482_Lipo_Voltage_Checker_2S_8S_.html

This connects to the balance lead of your lipo. Some you can set to a specific voltage and when the first cell dips below say 3.5. Loud beeping. I mean really loud I use them on my planes sometimes and hete them clear as day from 1000ft. Downside you need one for each pack. Plus side there cheap but work good. I'm coming from an rc background so some of my ideas won't cross over to e bikes.

I think I'm going to have to sell my v2100 though. I can't find a good mounting option for my batteries.

Thanks for that, I just bought 2 on ebay. Should be covered for up to 16s now.

 

[Baron]

I have my 72v 1500w controller working properly now. There was a "self-learn" wire that teaches the controller how to run sensored. Basically you connect everything on your controller to your bike normally, but also connect the self-learn wires. Turn the controller on, the wheel will start spinning on it's own. If it spins the wrong way, unplug the self-learn wire and plug it in again. It should spin the right way, unplug the self-learn wires and you're done. The controller has now "learned" how to run sensored with your motor. The self-learn wires should be disconnected during normal operation. This saves you the hassle of dealing with phase/hall combinations hunting for the right combo that runs forward smoothly.

This site was really helpful in setting this up: http://www.etotheipiplusone.net/?p=2373

Running this motor at 20s (74v nominal) is pretty overkill but if I get a temperature sensor installed I'll feel a little better about it.
Now I need to find out how to disable the LVC so I can run lower voltages...maybe get a cycle analyst too.