Looking for advice on a new controller

[MrSpeedy]

Hi, I'm fairly new to the Ebike world with only 5-6 months of riding. But now I would like to upgrade my bike for a touch more speed. My bike has a 48v17.5ah battery, and a Bafang 750 hub motor. The controller I have is speed limited at 25 for throttle only and 28 for pedal assist. Its rated at 25 peak amps. I'd like to raise the speed to 32-35 on throttle due to the fact I ride along roads with traffic at a much faster speed than me and feel i need just a bit more. My current controller is limited. Is there any other controller that can work with setup? I've been reading through this site and there is a tremendous amount of great knowledge here. I'm hoping someone can assist me. Thank you to everyone in advance.

 

[vfr400]

Why don't you unlimit the controller you already have?

 

[MrSpeedy]

Why don't you unlimit the controller you already have?

I've actually been trying, the controller I have is a Lishui. I've looked everywhere online and can't find anyway to unlock it. There's a program I think can download but there's no mention of a way to access the settings or needed wire or where it goes. Everything I've read, it seems the Lishui controller is extremely difficult to unlock.

 

[vfr400]

I've actually been trying, the controller I have is a Lishui. I've looked everywhere online and can't find anyway to unlock it. There's a program I think can download but there's no mention of a way to access the settings or needed wire or where it goes. Everything I've read, it seems the Lishui controller is extremely difficult to unlock.

OK, I thought it might be a Bafang controller to go with your motor, especially as it's 750w. I don't think I've ever seen a 750w Lishui controller. How many amps is on the label and where and how have you installed it?

 

[MrSpeedy]

This is the controller that came with the bike...

 

[MrSpeedy]

It came installed on the bike, its a Revibikes Cheetah.

 

[vfr400]

You can get a KT controller from BMSBattery. Also look at Topbikekit, Greenbikekit and PSWpower. Assuming that you have a sensored motor, you want the one they call sine wave torque simulation controller. You have to get the LCD to go with it. You need the 12 mosfet one - S12S from BMSB.

Check the size to make sure it fits.

 

[MrSpeedy]

Awesome thank you, I will look into it

 

[MrSpeedy]

You can get a KT controller from BMSBattery. Also look at Topbikekit, Greenbikekit and PSWpower. Assuming that you have a sensored motor, you want the one they call sine wave torque simulation controller. You have to get the LCD to go with it. You need the 12 mosfet one - S12S from BMSB.

Check the size to make sure it fits.

So, I have a question.... I have the 750w bafang motor, I looked for the controller but the BMS site wont load, but i found specs elsewhere. It states that its a 500w controller... Why would this work as a replacement controller to help me gain a bit more speed if its only rated at 500w? Im asking cause I don't know.

 

[vfr400]

So, I have a question.... I have the 750w bafang motor, I looked for the controller but the BMS site wont load, but i found specs elsewhere. It states that its a 500w controller... Why would this work as a replacement controller to help me gain a bit more speed if its only rated at 500w? Im asking cause I don't know.

The power they quote is meaningless. Your old controller is 25 amps, so you should replace it with another 25 amp controller, or higher if you want more power. Here it is from Topbikekit at 30 amps. You can turn the power down in the LCD if your battery can't handle 30 amps. Check the size and don't forget the LCD3:

T12S 36V/48V750W-1000W 30A KT Sine Wave Controller For ebike [T12S 36V/48Vsine wave controller] - $31.35 : Zen Cart!, The Art of E-commerce

Zen Cart! T12S 36V/48V750W-1000W 30A KT Sine Wave Controller For ebike [T12S 36V/48Vsine wave controller] - ★★★★★ T12S 36V/48V750W-1000W Torque Simulation Sine Wave Controller For ebike 1--Rate Voltage: 36V/48V Compatible 2--Maximum Current:30±1A 3--Low Voltage Protection:DC30±0.5V 4--Speed...

www.topbikekit.com

 

[MrSpeedy]

Ok gotcha, but you mentioned something about the battery also, how can I tell how much the battery can take? Its a 48v 17.5ah. Do I also just multiple the volts and amps here also to get watts?

 

[vfr400]

Ok gotcha, but you mentioned something about the battery also, how can I tell how much the battery can take? Its a 48v 17.5ah. Do I also just multiple the volts and amps here also to get watts?

The only place is in the battery listing. you should consider the continuous current as well, but the deal-breaker is the mac current or burst current. The BMS will cut when you go over the max current as a means of protection, so if your BMS allows 25 amps and you try and draw 30 amps, it'll cut out. Your battery will probably be OK.

It's best not to think about watts. It's current that gives you torque, which is what you feel as power. 30 amps will accelerate you 20% faster and allow you to clump 25% steeper hills with the same effort as before.

The KT controllers have current control, so on level 1 you might get 2 or 3 amps. You only get 30 amps on level 5, so you get lots of options to conserve power and pedal as hard or as easy you want.

 

[MrSpeedy]

The only place is in the battery listing. you should consider the continuous current as well, but the deal-breaker is the mac current or burst current. The BMS will cut when you go over the max current as a means of protection, so if your BMS allows 25 amps and you try and draw 30 amps, it'll cut out. Your battery will probably be OK.

It's best not to think about watts. It's current that gives you torque, which is what you feel as power. 30 amps will accelerate you 20% faster and allow you to clump 25% steeper hills with the same effort as before.

The KT controllers have current control, so on level 1 you might get 2 or 3 amps. You only get 30 amps on level 5, so you get lots of options to conserve power and pedal as hard or as easy you want.

Ok , thank you very much for all your help, this is an awsome site

 

[MrSpeedy]

Hi again, sorry bout the million questions but, I went back to the site to study the controller more and realized that my motor plug is different. I would have to hardwire the motor. Is there a place for a wiring diagram?

 

[vfr400]

Hi again, sorry bout the million questions but, I went back to the site to study the controller more and realized that my motor plug is different. I would have to hardwire the motor. Is there a place for a wiring diagram?

All modern decent controllers work the same:
3 motor phase wires
5 hall sensor wires plus one speed sensor wire
2 battery wires
3 throttle wires
3 PAS wires
5 LCD wires (unless it has LCD light connector)
2 wire brake connectors (sometimes additional 3 wire ones.

You can always cut connectors off and join the wires.

Some controllers have additional things like self-learning wires, three-speed switch, light switches, additional power wires, high level brake switch, ignition wires for a separate ignition switch, cruise control , EABS, etc, which can mainly be ignored or used as you wish. Always leave the cruise control jumper disconnected.

You can buy motor cables with the right connectors on Ebay to save a lot of work. you might have to swap over a couple of pins in the hall connector:

E-Bike Parts Motor Cable Connector Electric Bicycle Waterproof Useful Accessorie | eBay

Find many great new & used options and get the best deals for E-Bike Parts Motor Cable Connector Electric Bicycle Waterproof Useful Accessorie at the best online prices at eBay! Free delivery for many products!

www.ebay.co.uk

 

[MrSpeedy]

Ok, kool, this will be a neat little project to do, thanks!

 

[vfr400]

Ask again if you're not sure of anything when the controller arrives.

 

[MrSpeedy]

Hello, so the controller has arrived and I'm looking it over listing what control wire extentions Ill need, and I realized, Im going to have to extent either the motor wires or the battery wires. Is there a preference to which should be lengthened and how long? I know if I extend either one Ill have to go up in wire size, but the size will decrease again once at its end point.

 

[Nealh]

Battery wires are easiest to extend, though one can also buy 9 pin motor wire extensions though might be a bit too long.