one more try at sorting out this flaky motor issue ...

[woofnbike]

yes, poor connections on the phase wires. sheesh. now at least the motor still runs. i changed the order of the phase wires. only the original one turns the wheel. the other two combos made the motor sound like it was running but the wheel didn't turn.
went ahead and ordered that controller. guess i can send it back if it doesn't help.

 

[woofnbike]

well, crap. it looks like my new controller doesn't have plugs for a display. instead, maybe, it's got something labelled '3 speed line,' which translates as 'high, med, low speed.' with those, i gather that the moment you connect the battery, everything is powered up as your chosen speed with no way to turn it on or off. then again, maybe i'm not thinking about things right. this was one of the few controllers i saw that didn't require hall connections. perhaps there's a workaround for the display on/off issue?

 

[woofnbike]

hello? anyone home? meanwhile, i can't find a sensorless controller anywhere. the ones linked to earlier in this thread are all OSS and no alternatives have announced themselves. crumb.
just grasping at straws here, but maybe i'll try hooking up the hall wires and see if that makes a diff. i mean, what else is there left for me to try, except a great big heave-ho into the trash barrel with the whole kit-n-kaboodle?

 

[TommyCat]

perhaps there's a workaround for the display on/off issue?

The controller is enabled by providing full battery power to the smaller RED wire, one of the 3 at the battery connector. (Two RED, one BLACK.)
This can be verified by reviewing the “product description” on the link for your new controller. Under “how to connect” item #2.

This circuit is often know by “ignition”, or ”key lock”. Althogh being high voltage, it uses very little current. And as such can easily be controlled by a switch and run thru typical E-bike cable wiring. Only until this circuit is made, will 5vdc be available for the electronics.

Do NOT get this high voltage mixed up with the low voltage throttle or controller electronics wiring!

To start, you could just jumper this connection to verify operation, or add a switch to this jumper. Or just turn your system on and off by battery connection.

Later if desired, you could upgrade your thumb throttle or add switch controls to include.
Keyed switch or power button. (ON/OFF)
Cruise control button. (Momentary ON) Please verify the ‘momentary‘ first.
3-speed selector switch. (On/Off/ON) Three wire.
Battery voltage indicator. (Easily available with key switch)

If available in the configuration you desire, to make it easy to control your new and previously liked features.

 

[woofnbike]

i jumped the connection and after a bit of fiddling the motor came to life at full speed. guess i'll have to find a suitable keyed switch now, so i can get on/off and voltage.
thanks for all your help TC. could not have gotten this far without you, obviously!

edit: think something like this might do? https://www.amazon.com/Haosie-Throt...efix=ebike+voltage+display+key,aps,145&sr=8-1

also, i noticed that the new controller is rated for 17a while my battery is a 10a one. is that something to worry about?

 

[TommyCat]

Hey, great way to start the day! Congratulations on a job well done. Glad to help.

Thoughts on the key switch selection…
Note that it doesn’t have a throttle included. (Not that you need another one, but if you don’t have the room…)
And a blue voltage display might be easier to read. (But the red does go well with your bikes color.)
I like my cruise feature a lot and would recommend it. So you would need a button. But I do use a bike…

i noticed that the new controller is rated for 17a while my battery is a 10a one. is that something to worry about?

I don’t think you’ve ever mentioned your battery’s voltage or chemistry. Or the wattage of your motor?
But tripping a BMS often would not be desirable.

If you’re lucky, perhaps jumping the 3 speed switch for the “low” speed would keep your amperage draw low enough.
If not, I’ve got a throttle mod that will restrict the top end for you. Oh boy!

 

[bananu7]

From what I've read, the new throttle with the new controller works fine. That being said, if you ever doubt a throttle again, taking a couple of resistors instead is the easiest way to substitute for one. Most controllers run max throttle setting lower than the supply voltage as a fault protection mechanism, but almost always running regular potentiometer throttles will have the middle somewhere in the middle.

So, if you take two (10k) resistors in series across VDC and GND, you can use the middle point as a 50% voltage divider for a 50% throttle signal. Resistor values don't really matter that much as long as they're the same and in reasonable (100 - 1M typical) range.

VDC(red) ------ R1 ----- R2 ------- GND(black)
                     |
                     |
              throttle input

Thusly, for a 5V (typical) signal, VDC-GND should be about 5V, and throttle input - GND exactly half that.

A throttle potentiometer does exactly that, except when you twist the throttle, you increase the R1 while simultaneously decreasing R2, opposite in the other way. Different proportions of R1 and R2 result in different voltage drop across R1, which in turn means that the throttle input sees proportionally higher or lower voltage.

 

[woofnbike]

TC: i'll look for a blue voltage display and will report back. meanwhile, here's the battery info. and jumping black to brown on the 3-speed connect does indeed bring the speed down. plan to take a test ride tomorrow or the next day.

bananu7: thanks much for the info!

 

[TommyCat]

It would be nice to have a current/amperage reading to see what you’re pulling and to keep it under the battery max.

I see that your multi meter maxes out at 10 amps, right at battery max output. If you desire, you could temporarily put it in series with a battery power wire to keep an eye on it. If you’re careful with the throttle and keep the run times short. Hill inclines will increase current draw.

I use this meter for readings, as seen here…
1st Build & E-Bike rider-Magic Pie V5 (rear) -Bottle Batt. 52v*11.5ah-Huffy Parkside - Electricbike.com Ebike Forum

 

[wturber]

<snip>

also, i noticed that the new controller is rated for 17a while my battery is a 10a one. is that something to worry about?

Is that a 10a battery or a 10 amp hour battery? 10 amps seems kind of low for an ebike battery but seems more in line for the amp hour capacity.

Also, I didn't read back about your reasons for a key switch. But if it is for security, you'll want to do something to protect the wires. If exposed, it will be super easy to bypass that keyed switch. A nicely hidden or camouflaged switch may be both simpler and provide better security.

 

[woofnbike]

wturber: thanks for weighing in. how could i tell if the battery is 10a or 10 amp hour?

TC: i ended up getting this. i'll prolly be back asking for help sorting out the wires, when it arrives. green display, not red. https://www.amazon.com/dp/B0CLH8JK68?ref=ppx_yo2ov_dt_b_fed_asin_title . i assume the 3-pin connector wires are for the throttle. that leaves the yellow and purple for the on/off switch. how should i hook them into the controller?

 

[wturber]

wturber: thanks for weighing in. how could i tell if the battery is 10a or 10 amp hour?

TC: i ended up getting this. i'll prolly be back asking for help sorting out the wires, when it arrives. green display, not red. https://www.amazon.com/dp/B0CLH8JK68?ref=ppx_yo2ov_dt_b_fed_asin_title . i assume the 3-pin connector wires are for the throttle. that leaves the yellow and purple for the on/off switch. how should i hook them into the controller?

It would depend on the battery, how it is labeled, etc. Why is it that you think the battery is rated for 10 amps? Note that 10ah labeling refers to capacity or amp hours, not amps. That's the key distinction you need to be aware of - ah = amp hours; mah = milliamp hours. If the battery is manufactured and the manufacturer wisely installed a fuse, you can check the rating of the fuse. The rated output of the battery will generally be a bit below the fuse rating. So if your battery has a 20A fuse, the battery probably safely outputs a bit less than 20 amps. If it has a 10A or 15A fuse, then maybe the battery is really does have a maximum 10 amp output.

If you know the cell configuration you could make a good guess about the battery's amp hour capacity that way as well. Typical 18650 cells will have a capacity of 2-3 amp hours per cell. So if your battery had 4P configuration, you would assume a capacity of 4 * 2-3 amp hours or 8-12 amp hours for the assembled battery. 10 amp hours falls right in that range and would be a reasonable estimate for a 4P battery.

 

[woofnbike]

in the product photo above, the battery is listed as 35v 10a. here's the label on the battery -- very hard to make out anything beyond 378 WH. what's it tell us, do you think?

 

[E-HP]

in the product photo above, the battery is listed as 35v 10a. here's the label on the battery -- very hard to make out anything beyond 378 WH. what's it tell us, do you think?

View attachment 360688

How well was the battery maintained over the last 8 years?

 

[bananu7]

in the product photo above, the battery is listed as 35v 10a. here's the label on the battery -- very hard to make out anything beyond 378 WH. what's it tell us, do you think?

View attachment 360688

It's 36V, 10.5Ah, 36*10.5 = 378Wh.

 

[woofnbike]

e-hp: i don't know. all i do know is that it hasn't seen a lot of use but i guess that's not the same as quality of maintenance.

bananu7: ah yes, i can see that now. thanks.

so ... how many amps is the battery? i'm still trying to see how it'll do with the 17-amp controller ....

 

[TommyCat]

i assume the 3-pin connector wires are for the throttle. that leaves the yellow and purple for the on/off switch. how should i hook them into the controller?

It would be a reasonable assessment. But I would recommend that you test the two wires thought to be going to the switch to verify this.
With the switch "ON", the resistance is 0 ohms. (circuit closed) With the switch "OFF", the resistance is infinity. (circuit open)

Once verified the YELLOW wire goes to the battery+ or positive.
And the BLUE wire goes to the small RED or "ignition" wire only. Which you have temporarily jumped at this time for controller operation.

As the product page doesn't exactly point these connections out. I've referred to like products.

Even if switched, these two high voltage wires would not cause any damage. But if reversed, you would notice that you couldn't turn the digital voltmeter display off with the switch though.

If you have ANY doubt, carefully open it up and see where the colored wires go to.

 

[woofnbike]

thanks much, tc. just to be clear: once verified, yellow goes to the fat red wire and blue goes to the small red wire. right?

will tread carefully (i hope) and report back ...

 

[E-HP]

so ... how many amps is the battery? i'm still trying to see how it'll do with the 17-amp controller ....

Can't say for sure without opening the pack and testing the cells. The number one rule on Chinese built products is that the parts will be spec'd with the absolute minimum, of performance and price, to meet the specs on the sales sheet. That's if you're lucky and the seller is somewhat ethical.

Scooter specs:

Motor 350W Bafang ​

Battery 36V, 10A*​

Speed 26km​

Mileage 40km​

Battery specs:

36V​

10Ah​

378Wh​

Controller specs:

36V​

12A​

350W​

​

Doing some math:

Battery: 36V x 10Ah = 360Wh; doesn't pencil out with 378Wh. Possibilities, battery is actually 10.5Ah, or actually 360Wh​

Controller: 36V x 12A = 432W; running it at full throttle may be an issue based on the 350W rating​

Scooter spec/sales sheet: *10A looks to be a typo, based on the controller requirements of 12A​

​

Applying the math:

A speed of 26km seems reasonable. In order to meet the 40km range spec, and assuming the battery capacity is 378Wh, then the scooter has to be capable of meeting 378/40 = 9.45Wh/km (or 15.21Wh/mile). I'm skeptical about whether the scooter can meet the mileage spec, even with a new battery​

On the battery, I agree that it's likely a 4P pack (10S4P). Most of the generic Chinese cells I've seen are either 2500mAh or 2600mAh, and capable of 4A-5A continuous. So, if the pack is 10.5Ah (being generous), then it's likely made with 2600mAh cells since 2.6 x 4 = 10.4Ah (rounding up to 10.5Ah; rounding up seems to be a common convention). However, and more likely, they are 2500mAh cells, which would result in a 10Ah, consistent with pack specs. Pack discharge rating when new might be between 16A and 20A (4x4 or 4x5). Applying the number one rule again, my guess is 16A, which is still enough to meet the 12A current limit required by the controller.​

​

Conclusion: The battery may possibly have been on the margin for supplying enough current to a 17A controller, when new. However, at 8 years + of age, with unknown history and maintenance, I wouldn't use it for anything greater than the stock 12A rating, if at all. The range spec seems inflated, based on the components, but range is usually the most squishy spec anyway.

​

​

​

 

[woofnbike]

well, thanks for such a complete answer but man o man is the conclusion depressing. now i don't know what to do, since it's doubtful i'll be able to find a sensorless 12A or less controller anywhere. from what you say, i guess i should retire the battery but then that means retiring the whole damn project. crumb.

 

[E-HP]

Just don’t ride around at full throttle until you can replace the battery.

 

[woofnbike]

okay, will do. i take it slow at all times anyway ...

 

[TommyCat]

Whist reviewing possibly using your old display wires for the wiring between your newest throttle and new controller.
It suddenly occurred to me that you could actually use your existing display to turn your controller off and on.
As well as use the rudimentary battery indicator lights as before. Of course, your PAS levels and walk mode could not be used any more, and hard to say how much longer it may work....
It would be a just a hair more difficult to wire in, and not as elegant or nice as the upgraded digital display.
But an option I thought you may want to know about.

 

[woofnbike]

i went w the digital display and had to cut wires, so no going back. the big news is, i took the wee beast out for a ride and it went swimmingly well. everything works just like i'd hoped, thanks to you, TC, and everyone else who chimed in. super pleased, super happy and i am so grateful for all the help. bueno beyond words!

 

[woofnbike]

welp, disaster strikes. all was fine until a buddy 50 lbs heavier than me took the thing up a hill and at the top, the scooter went dead. figured the battery had run out of juice. came back, charged up, pressed the on switch -- nada, nothing. turned the scooter over, only to see that the phase wires were completely shorted out and fried. yikes. took em apart and linked them together again, hit the switch, and ... the voltage meter flickered briefly to life, then went dark, never to return to the green.

could be my wiring shorted things out or i dunno.

in any event, i don't know what damage i've done and how permanent it is but later today, i'll go to the top of this thread and start testing everything again, hoping i didn't kill the motor.