Hacking a Couple Stromers

[GCinDC]

cool, thx allex.

re the batt, no doubt it's shrink wrapped, but it might be interesting to reveal the bms. probably looks something like this (tho this is 48V one)

screenshot taken from this vid:
[youtube]ASV9VrNpn3U[/youtube]

 

[Allex]

Well, that video...Just an awsome bike!

 

[dbaker]

78 cells, 48 volt.. perhaps 13s6p for 12ah

Sad that you can't revive the display and the phone features

Or maybe you can

 

[GCinDC]

Sad that you can't revive the display and the phone features

no, no, that vid is of the latest version. mine are several versions older, likely the first version - why i removed "ST1" from the title. i'm not sure what version they are, and the local bike shops that carry them don't know either! :lol:

 

[SamM]

I was seriously looking at the Stromer ST2 when I found the Fighter for sale. The 7k price and 28mph top speed scared me away. These look like great bikes though. Great features. I wish my Fighter had that much technology integration in it.

SamM

 

[GCinDC]

wired the temp sensor to the hall + instead of the GND, so i had to take this lovely motor apart again to fix it..

then i cut existing throttle and ebrake wires in order to connect to adaptto connector/pigtail (lower left):

since existing throttle colors were brown, red and orange, it took a bit of trial and error w/ the ebike tester to sort it out...

all soldered up:

done and perfectly sized to connect to ebrakes connectors, not three feet longer like i usually do. lol

 

[Alan B]

Nice Project!

There are a couple Stromer bikes at work. Very nice, but they do seem to fail from time to time. They are designed for bike shop swap-out, not repair. So they make them reliable but not serviceable.

One fellow I know has had to have replaced (under warranty) rear wheel (torque sensor/control problems), battery (failing to take full charge), then whole bike (more battery issues). They're probably overstressing the battery, or their BMS has problems. But they're very nice when they work. Hopefully they have straightened all that out in the new models.

 

[GCinDC]

wheel back together. ran adaptto autodetect on the bench w/ stromer batt using aligator clips:

rewired batt port inside bike to go thru frame to controller under BB:

i fastened all the wires up ship shape, popped the battery in, adjusted the min/max voltage and gave her a ride.

a tiny thrust of power under boost mode (20A), but then power dropped rather quickly. seemed to have some power at start, but faded at speed. and the odd thing (clue?) was that the speedometer never read above 4mph. seemed like to it, 5mph read only as 1mph. 10mph read as 2mph. 15mph as 3mph, and 20mph as 4mph. so this makes me think there may be some odd controller configs.

actually, first i just thought the batt was toast; that it was floating up at full charge voltage, but it was gutless. voltage was read as low as 36V under load, but that's not that bad..

anyway, to rule it out, i took it out to have a peek:

i unscrewed the leads to borrow the connector...

and put in 2x 6s packs in series, for 44V nominal

got a nice kick at first, but then gradually, power drops to nothing..

and the same deal w/ speedometer, max 4mph when should read 20mph.

here's a vid of acceleration. unless i'm braking, it's WOT:
[youtube]t4yxZ34uEHk[/youtube]

i have boost profile set to 56A/146Ip A.

damn, i thought i'd have this done today.

any thoughts anyone?

be nice if the batt was ok, and it was just an adaptto callibration thing.. i count 18 poles on the motor, right?

 

[dnmun]

i counted 16 magnets so that would be 8 magnetic poles i think is how it should be entered. maybe miles or someone who knows can comment.

 

[GCinDC]

i could aways get it running with another motor.. here's the hs540

but do you see that? the freewheel side is in tight and the wheel's more or less centered, but the disc is over an inch off, and i'll need a million washers:

my rule maxes out at 153 and is at least 5mm short:

certainly heaver than wanted, but it's got the temp sensor and all the connectors. just a wee crack in the rim. :x

still, a worthwhile exercise even w/o rear brake to test the 36V batt...

speaking of which:

 

[TSAR]

8 pole pairs, Dnmun is right. With a 26" wheel your adaptto speed ratio number should be between 250 and 280 depending on tire size.
It would still run autodetect with an incorrect speed ratio, but you would get the speedometer errors and power loss. Which is exactly what is happening. I learned all of that the hard way trying to calibrate a BMC motor.
How wide is the ultramotor axle, shoulder to shoulder? Both my motors came off A2Bs, and they are 142mm shoulder to shoulder.

 

[GCinDC]

8 pole pairs, Dnmun is right. With a 26" wheel your adaptto speed ratio number should be between 250 and 280 depending on tire size.
It would still run autodetect with an incorrect speed ratio, but you would get the speedometer errors and power loss. Which is exactly what is happening. I learned all of that the hard way trying to calibrate a BMC motor.
How wide is the ultramotor axle, shoulder to shoulder? Both my motors came off A2Bs, and they are 142mm shoulder to shoulder.

cool, thanks. the axel's gotta be around 157 mm shoulder to shoulder. and it's not too long outside the dropouts either. barely enough room for a washer on the drive side. both bikes seem to have come with nordlock washers, but only one will fit on drive side.

thanks for tip about speed ratio. i ping allex about manual adaptto configs and am pasting his words from elsewhere here, for my own reference:

Take "Angle Corr" and "Ind Timing"

First Angles, lift up the wheel accelerate to 10-15km/h and adjust your angle so you have a smooth rotation. If the angle is wrong you will hear it and also the wheel will turn more slowly.
You can also test it on a very long stretch. Find a flat road and drive 15km/h with one setting, take note of the motor temperature and then change the value. If the temp. will get lower, then the new value is more correct, keep going until you get the lowest possible temp.

Same goes with Ind Timing. But this time you need to have a constant speed of ~50km/h. Take note of the motor temperature and then change the value. If the temp. will get lower, then the new value is more correct, keep going until you get the lowest possible temp.
Note: Dial OVS down to 0 when you do this.

Then you have PWR timing. Adjust this value so you have maximum torque when you go WOT from 50km/h.Works best at about +1,5-2,5 with Cro and my Crystalyte 5403

i won't be hitting those speeds @ 36 or 48V, but def need to remind myself i might need torque arms if i test above 20A!

 

[Allex]

Yeah if you have 37Volts then adjust your PWR when accelerationg from about 15-25km/h

 

[GCinDC]

mystery solved. there may have been two issues. the lipos i was using were too low, so they were actually dropping off the cliff. lazy mistake. but that didn't explain why the stromer batt wasn't working (which it is now)

i did a system reset on the adaptto controller and she purred like a kitten. actually, wasn't that noisy. this was the adaptto that i was just running on my dh comp, until i got the max-e. so while i had run autodetect on it, it still had all my other configs, except the bms settings which i'd already changed. i took a vid of the settings before, and i'm not sure which it was, but after the reset and another autodetect, ran great with new lipos, and very nicely on the 36V stromer pack, which i really want my wife to use over any lipos, mainly for charging.

maybe some pics/vids tomorrow.

oh, and thanks TSAR for the speed ratio tip. that really helped. i left it at 265 for now and seemed fairly close.

 

[dbaker]

Is it a wheelie machine now

 

[TSAR]

No problem, glad I could help.

BTW, that motor is a beast, I got it up to 40mph cruising speed (and more, up to about 47) on 21s and Lyen 18fet sensorless in a 24" wheel. That thing has a lot of torque.

Have fun with the other one

 

[dbaker]

Is the battery 10s5p, Samsung 22P cells? EM3EV sells a 36v 10.25ah frame pack with the 22P cells and the BMS limits discharge current to 20amps

http://em3ev.com/store/index.php?route=product/product&path=35&product_id=160

 

[GCinDC]

i should have scrutinized the pack, esp to understand capacity. def looks like those samsung cells tho. need to ride it around more to test, but here's the walkaround and test ride:
[youtube]HeYTx8IH7k4[/youtube]

 

[GCinDC]

the old lady has just received basic training for the modified stromer (by me of course) and wil commute on it tomorrow. i only put about 2 miles on it to test, but the battery level seemed ok. and she'll mostly pedal, using throttle only when nec.

her old 250W batts are dead. she's even been taking the charger in to work with her, which she hates doing, and only for a few strategic trickles of current. here's the old workhorse:

has 10,000 miles on it, easy. she's probably dropped it at least 10 times too. the thumb throttle snapped off a couple years ago and this little mod has been holding steady, lol:

so out with the old, in the with new, at least until i find a 36v controller to use and put the adaptto to a higher purpose, now that we don't have to worry about cell balancing, etc...

 

[GCinDC]

bike is working like a charm for commuting.

first day, return commute, she fooled around w/ menu and got stuck in charge mode somehow. made some changes and saved them, so hopefully nothing much!

chain fell off several times too, and got stuck next to miniE. need an inner chain guard.

here's the stats after there and back commute:

unfortunately, after charge, the battery doesn't go to 100%. the charge port is only wired to batt leads, so i guess since i'm not using charge port, the system doesn't know the battery's been recharged. she'll have to manually reset it until i can wire the charge port to the charge GND on the adaptto.

 

[GCinDC]

after a week, besides the stromer seat (which i replaced w/ comfort seat), the only complaint from the old lady is that it goes so fast she doesn't need to pedal as much!

i've been checking her bike at night, mainly to make sure she's charging it properly, but amused to see she's going faster and faster.

it's not so much about going faster per se, but being able to get to work/home quicker. :wink:

i have no idea what the range really is; at some point will have to run it down.

 

[dbaker]

How is the battery working out? Do you use the BMS on the battery and charge with a dedicated charger?

Forecast next week looks miserable. High of 32 on Tuesday. With rain on Monday there could be ice on Tuesday morning ride in. Are you recuperating or riding?

 

[dbaker]

Looks like you have max of 700 watts. For 36 volts this would mean you can use a 20 amp controller?

 

[GCinDC]

How is the battery working out? Do you use the BMS on the battery and charge with a dedicated charger?

battery seems to be working fine, but i need to check the voltage after the ride. anyone know the discharge curve for those cells?

and yes, using bms on batt w/ dedicated charger. has an annoying feature - it MUST be plugged into pack BEFORE AC goes on/plugged in or else it won't charge.

Are you recuperating or riding?

metro with arm in sling. sux about weather next week. i was liking the warm temps!

Looks like you have max of 700 watts. For 36 volts this would mean you can use a 20 amp controller?

she's got the miniE i was using two weeks ago, so i could easily up the current. just not sure how much the batts can put out. i suppose i could jack up the current and see what they put out, but i'm thinking that might be a good way to kill them, no? know what those cells are capable of?

 

[Allex]

10C in peak and
7.10 Cycle Life (2)
Each cycle is an interval between the charge (charge current 2150mA) with 0.05C
cutoff and the discharge (discharge current 4300mA) with 2.75V cut-off.
Capacity after 300cycles
Capacity ≥ 1600mAh (80% of Rated Capacity)


http://aku-bat.cz/index.php?s=download_userfile&id=2994&filename=1409928724.dat