Upgrade current bike

[Poeliii]

Hi all,

New member of the forums here, and electric bike user since May. I use my bike to commute (together with the train) and as its my only transport for all the rest too. I have a silent force bike, which goes upto 25km/h pedeling assist. It has a battery of 36V and goes ok. Flat I put it not on the highest assist I get 23km/h. Downhill I go 35-45 top. Now as I miss my train with only 7 mins from work I wonder if it is possible to upgrade this bike to make it go 30-40 flat? I have been reading around on the forums and I guess it's my controller which needs to be blocked/upgraded. Other than that, just using a 48V battery instead of the 36V won't work I guess? I have a 180W motor, so i don't know if it's possible to obtain such speeds with this motor.
My bike detects when I'm working too and has a cut out at 25km/h. How can I remove this 25km/h limit t make it go faster? (Not too fast of course, but an upgrade to 30-35 would be very nice!)
Thanks for the advice!

 

[Deleted member 4366]

What type of control panel is on the handlebars? If it's a LCD, a photo would help. LCDs normally have a secret setting for speed limit.

If you have no panel or an LED one, the restriction will be in the controller.

Take the side off the controller compartment under the battery and pull out the controller and any wires. Look for two single wires (often white) plugged together to make a loop. If it has them, unplug them. On older bikes, you sometimes see a loop of wire with a small potentiometer on it, which adjusts the speed.

If it doesn't have the loop of wire, the restriction will be inside via a jumper on the PCB.

In the worst case, it's software limited in which case it's not easy to change.

You can always get a new controller, but it depends how much space there is in that compartment. You need to measure your existing controller first..

 

[Poeliii]

Okay thanks for the tips, I took some pictures today.. Difficult thing is there is absolutely no information which controller is used or which motor. It has indeed an lcd display. My controller is in a housing which i can't seem to take out, so no acces to the controller it seems. Here are some pics I took.
https://www.dropbox.com/s/zd9mazq5orh6jmb/2014-09-17 12.53.46.jpg?dl=0
https://www.dropbox.com/s/3waeiw53isyv5op/2014-09-18 08.26.00.jpg?dl=0
https://www.dropbox.com/s/267wzbnoc7g0y8m/2014-09-18 08.26.16.jpg?dl=0
https://www.dropbox.com/s/m50q295r3f30x51/2014-09-18 08.33.24.jpg?dl=0
https://www.dropbox.com/s/2flvjc3smnhgcfy/2014-09-18 08.22.25.jpg?dl=0

Getting a new controller,the current one is rated at 36V 13A, would I need to get a controller than with higher max amps? like 15A or something?

 

[Deleted member 4366]

You press and hold the SET button for about 10 seconds to enter the setup. You'll see the display change when that happens. I think it's the SET button again (short press) to scroll through the parameters until you get to the speed limit. Use the up/down buttons to change it.

Sometimes, the speed limit is the advanced settings, so if you don't find it in the adjustable parameters, press and hold the SET button again for 10 seconds after you enter the first setup screen.

That will release the speed limit. The next thing you need to do is add some solder to the shunt. Put a blob of solder up the side of one leg to just reach the top corner -like in the photo below but a bit thicker and right up to the corner. Leave the soldering iron on the shunt long enough to heat it up and get the solder properly fused. This procedure will increase your current to about 18 amps, which will give a lot more oomph to your motor. Don't get greedy and try to solder further.

 

[Poeliii]

It worked nice! Don't know if I'll do the soldering already and upgrade too because i'm pretty sure it would void my warrant...

 

[D8ve]

Also it's technically illegal to yes a bike that powers over 25kph.
You are open to trouble but if you are carefull and don't take the **** then there is little chance of being caught.

 

[Poeliii]

Just tried one time increase in the setup (of 3 or more i guess), and the result is amazing. I wonder what the others might give me, though i want to keep it safe, and the speed i have now is great!

 

[Poeliii]

One question though, when i now drive on stand 4 its ok but it seems the level 6 is not a small difference. Can it be that the battery is already delivering max amps at level 4? If so, how can i resolve this? The controller is made for max 13A, can I change this one so the battery delivers more than 13amps or is there another problem i'm not seeing?

 

[flecc]

Yes, soldering the shunt will increase the current (amps) as d8veh has advised. He feels 18 amps is realistic. That won't fundamentally increase the speed more, just increase the power to maintain your higher speeds.

The shunt change won't make the battery more capable, but it will enable the controller to take advantage of anything the battery can deliver.
.

 

[Deleted member 4366]

The levels on your display relate to speed targets, not power limits. The controller has its own algorithms for deciding how much current to give to get you to the speed target. They normally depend on the difference between your actual speed and the target speed. Therefore, you may be able to get the maximum current in every level.

 

[Poeliii]

aha, thanks now i understand why the soldering is necessary... dont think i will do it but its nice to know