Suggestions how to go about this?

[Glenn74Swe]

Hello everyone! Glenn from Sweden here

.

(Yet another noob here having some questions regarding tuning an e-bike)

I have a Viarelli Fat Bike with the following components: 36v, 13ah, li-ion, 250w small hub motor, PAS assisted and a LCD computer. Everything preinstalled. (controller 12A, 6 fets labelled "LVBELAN" as manufacturer http://motorsweden.se/reservdelar/fordon/elcykel/viarelli-fatbike36/controller-fatbike36)
The bike is legally restricted to 25 km/h and like many others I would like to go a bit faster. Now, I don’t want a speed demon but I would like it to go in the 35-40 km/h range with PAS assist only. I can set the speed to 60 km/h on the LCD computer but that wont make the bike to go any faster. I have also tried to set the wheel size to both bigger and smaller but that doesn’t help either.

1. I understand that some controllers have a wire loop that, if you disconnect it, will increase speed somewhat. My controller doesn’t have a loop which led me to think that somewhere on the circuit board there is fixed loop although the cables don’t stick out. Any thoughts on that? On the underside of the circuit board there is a brownish capacitor (I think) that looks kinda out of place that I haven't seen on other controller boards. Is this some kind of restrictor? It looks something like this if I remember correctly: http://kaizerpowerelectronics.dk/wp-content/uploads/47nK-250-480x480.jpg (the numbers aside)

2. I’m really tossing and turning weather to modify the controller I have or to buy another one. I have read A LOT regarding tuning an e-bike the last couple of days but I am not getting any wiser. From my understanding the only way to increase speed is to up the voltage but I don’t want to buy a bigger battery and arouse the police. I want it to be a ”sleeper”. But if you can disconnect a cable to make a motor to spin faster then what happens inside the controller?

3. I know about the shunt mod and add solder to the traces to increase amp, but I am unsure to what swapping out the fets really does. Won’t that increase the voltage? (the caps are rated 50v by the way)

4. I have seen pictures of the hall sensors inside the motor and some sits pretty close together. Would separating them fool the controller into thinking that the speed is lower than it really is?

5. I don’t plan to use the bike to go offroad, but I will use it during the winter so I guess the cooling problem is solved. In the summer I will use the bike on plain straight roads without much hills.

6. Would I benefit from buying a controller with the following specs: 36v, 350w, 22A (http://www.ebay.com/itm/161826966209?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT), OR should I modify the controller I already have? I know how to solder and how to tinker, but I'm not a electric savvy guy.

7. If you wish I could take some pictures of the controller, but it is situated inside the frame in the small compartment between the battery and the paddle crank housing and it's VERY cramped.

8. Also, if anyone have a manual for this LCD computer I would be a happy camper! http://motorsweden.se/reservdelar/fordon/elcykel/viarelli-fatbike36/display-lcd-36v-fatbike36 The company where I bought the bike can't get hold of any manual and it has a ton of adjustable parameters that I don't have a clue what it is for.

9. Sorry about the lengthy post

 

[Glenn74Swe]

Thanks for the reply. I'll try to post some pictures of the controller shortly.

 

[d8veh]

It's very rare to find a speed limit loop on ebike controllers now. The speed limit can sometimes be adjusted through the LCD buttons. Try this:
As soon as you switch it on, press and hold the middle button for a long time to see if the display changes to settings
If that doesn't work, try again, but press and hold the + and - buttons.

One of those too might go to settings. If you don't find something that says 25 km/h, press and hold the same button/s for at least 10 seconds to see if it switches to more settings.

Let us know if either of those works.

If none of that works, you can use the KT controller in your link, but be aware that you need a KT LCD to go with it. It would probably be a good idea to get the controller, LCD, throttle and PAS together to make sure that they're compatible. That KT controller is for sensored motors so make sure your motor is sensored ( 3 thick wires plus 5 or 6 thin ones), otherwise you need the S06P controller from BMSBattery.com.

 

[Ianhill]

Is there a magnet on the rear wheel with a sensor in the frame that picks up the wheel speed, On the Bosch and Yamaha bike the sensor can be spun round and the magnet placed on the pedal arm so it measures the pedal speed instead of the wheel that way the speed is way out so it will accelerate upto 30mph there abouts with pedaling but think its doing much less. I would not do a full discharge at 30mph the bike is not designed to do that I have no experience with it or I'm I responsible for any damage occurred but it should be fine many have done it.

 

[Glenn74Swe]

d8veh:
Like I said in my initial post I can set a bunch of parameters on my LCD, however the abbreviations are very confusing. It doesn't say "Max speed" and give you the option to adjust it. It says "LS" and from what I have found on the net this have to do with adjusting the speed. However, it doesn't matter if I set the speed to 60 km/h. The max speed is still 25 km/h. (just to be clear, the LCD doesn't say km/h. It just say "LS" and then you can adjust it between 12 and 60)

What is the difference between the "KT LCD" and my LCD?

Ianhill:
There is no sensor/magnet on the spokes what so ever.

 

[Glenn74Swe]

I uploaded a video about the settings on my LCD: https://youtu.be/klBhtnGj_uw

 

[Glenn74Swe]

Managed to get the controller out. Even if nothing can be done with this controller perhaps the pictures can help someone else in the future.

edit: for some reason the pictures was rotated when I uploaded them.

The fets are: HY1707 FS014322 G

 

[Glenn74Swe]

Almost forgot. This is the only marking I can find on the motor.

 

[dogman dan]

12 amps controller will limit max watts, and hence speed. Bigger controller or shunt mod may stress the hell out of your battery though.

 

[d8veh]

It's a standard Chinese controller for hall sensor motors. You can replace it with a S06S and a S-LCD3 (or s-LCD5) display from BMSBattery. You'll have to thread the LCD wire through- and the throttle if you don't already have one. You'll also have to cut some of the connectors off and solder the wires directly.

 

[docw009]

Right now, the thinking is your speed is not software limited, but is motor/current limited. If it were me, I'd try the shunt mod, soldering a wire across the two hoops in your shunt. If that worked, then I'd consider smoother street tires like the Vee Rubber speedsters, which made my Fat Bike a lot easier to pedal, so they might increase top speed if there is no speed limiter.

If the shunt don't work, then you are software limited. By the way, is there a speed sensor on the frame? Looking at the controller pics, there doesn't appear to be one in the motor, as what appears to be your Hall sensor connector only has five wires. (There would be a sixth white one for rpm.) My controller has a programming setting for the #pulses/rev for a wheel rpm sensor. If you could ID that parameter, that could be another way to trick the controller. You're already near the biggest wheel size, so there's no tricking the controller that way.

 

[Glenn74Swe]

12 amps controller will limit max watts, and hence speed. Bigger controller or shunt mod may stress the hell out of your battery though.

How do I determine how much my battery can handle?

It's a standard Chinese controller for hall sensor motors. You can replace it with a S06S and a S-LCD3 (or s-LCD5) display from BMSBattery. You'll have to thread the LCD wire through- and the throttle if you don't already have one. You'll also have to cut some of the connectors off and solder the wires directly.

So if I buy another controller I can't use my display?
edit: my display has a round plug connector but what I meant was: can I use my display if I cut off the plug and strip the wires? Or is it two different standards?

If it were me, I'd try the shunt mod, soldering a wire across the two hoops in your shunt.

Perhaps I'll try just that.
edit: I just did the shunt mod. Yesterday I decided to get a thumb throttle from the same place I ordered the bike and today I got it in the mail. Before the shunt mod the bike did 26.6 km/h with the bike upside down and the wheel free spinning at full throttle. After the mod it went up to 27.1 km/h. I also took a very short trip and it didn't blow up (The battery is not fully charged though).

No, I can't find any sensors on the frame.

Sorry, the picture of the bike is a bit misrepresentative. I have already bought and fitted smoother road tires, but very soon it's winter and i'll be shifting back to the off-road tires.

 

[ColinB]

About the battery; from what I know, a battery is rated to handle a certain amount of power. If you are pulling too much power from it, it will:
- heat up. (Heat is bad.)
- drop voltage when used hard.
- give you lower capacity
- wear out sooner.

If your bike goes 27.1km/hr upside down, that tells you that 27km/hr is the maximum speed for that motor. To make it go faster then that, you will need to increase voltage. Which means a new controller and battery, and very possibly a new motor with a higher power limit.

If your riding speed is say 15km/hr that tells us the motor is having trouble reaching it's maximum possible speed. Adding power can help. But then what is your "weakest link?" Or make your bike more efficient - the smoother tires, proper tire inflation, no brakes dragging, etc.

An amp meter/voltage meter on your battery can be very handy for this type of thing. I like the ebikes.ca Cycle Analyst but there are other options too.

Colin

 

[d8veh]

I can guarantee that you won't have problems with the battery current. You can go from the present 12 amps to 18 amp. which will give you 50% more torque, but it won't give you any more speed. The extra speed you saw was just because it overshot the speed limit because it got there more quickly and the controller didn't react in time.

You can check whether the motor is limited by the controller. If it has the same maximum speed whether the battery is fully charged or nearly empty, it's limited by the controller.

I doubt that your LCD will work with any other controller. It'll switch it on, but that's about it. The software in the LCD has to be matched with the software in the controller.

 

[Glenn74Swe]

Great answers. Thank you all.

Tonight I took the bike for a little longer trip (about 6 kilometers) with the new thumb throttle and the shunt mod. Everything went fine and i could not fel any particular heat from the controller.

I noticed that the display said 15W-25W when ridning on flat ground with full throttle, and I reached around 25 km/h when maxed out.