S12S 500W Torque Simulation Sine Wave Controller

[anotherkiwi]

I am going to get one of these, I know it is big but I have the luxury of sufficient space to tuck it away.

Quick question:

Is there enough room inside to tuck away the unwanted wires (speed sensor, throttle...)?

 

[Deleted member 4366]

There's several versions. The last one I had was a smaller PCB in a big case, so there would be some room in there, but things do get a bit hot, so there's a chance of melting through wires.

 

[anotherkiwi]

OK thanks. Best to clip them leaving a tail long enough outside for soldering "in case" then.

 

[anotherkiwi]

Lets say (for fun) I get one of these https://bmsbattery.com/ebike-kit/736-s12sn-72v1kw-40a-torque-simulation-sine-wave-controller-ebike-kit.html and limit my use of current to 10 A (assistance level 3). Chuck an 18 S 72 V LiPo battery behind it and plug the lot into a 36 V 201 rpm Q128C.

I double V so multiply speed X 2 = 400 rpm = ? km/h (65 km/h?)
I am only feeding 720 W to a 500 W rated motor so not much extra heat

Or is the rocket science more complex than that?

 

[Deleted member 4366]

It's more complicated than that. The Q128C spins to 28 mph at 123S in a 26" wheel, which would be 39 mph at 18S. Motor efficiency drops off rapidly when you give full power below 50% max speed and goes into the danger zone at any speed below 30% max speed, in this case 13 mph. With low efficiency, you get low power, so your 720w would only be 240w at 13 mph, plus 480w heat. At 10 mph, it would be even worse and you'd have very little power to pull away from a start. Hill-climbing ower would also ne compromised in the same way.

The only way that could work is if you used only pedal power up to say 13 mph, then used the motor to boost your speed, like some people do on road bikes with small motors.

Normally people want it the other way round, with assistance at low speed and for climbing.

 

[anotherkiwi]

Having a gander at the KT web site after having downloaded the bluetooth software and firing it up (damned good software!) I come away perplexed. They make controllers with waterproof connectors, why isn't anyone selling those? They make them in red and black as well as silver, ditto?

So I have decided I want a KT bluetooth dongle:

- alibaba first shop $70 and don't ship to France
- another one $400...
- BMSbattery with a stupid square wave controller 30.60€...

S09P 500W Torque Simulation Square Wave Controller = 18.70 alone, with Bluetooth dongle 30.60€. Difference a Y splice on the LCD conector plus the dongle = 11.90€.

I am going to try and negotiate a S12S with the dongle and without the Y splice for 40€

Our controllers should look like this:

More or less, if there was a light output it would be even better. And another version with a cable for the external speed sensor... How many cents do the resellers save by skipping the water resistant plugs? Compare, same controller...

 

[Woosh]

They make controllers with waterproof connectors, why isn't anyone selling those?

all the big companies make them, the choice between them has more to do with inventory and how much (or how little) you want to expose the system parameters. In general, from the suppliers' point of view, as little as possible.
Another point is the plug system. The old style JST may seem messy but it makes sense to all and most people can cope with replacing or even repairing broken wires. The push click connectors run the risk of bending pins. No system is perfect.

 

[Deleted member 4366]

It's almost impossible to test what's wrong when they use those waterproof connectors. You can have the situation where you have a faulty display that kills controllers. All you can do with the waterproof connectors is replace parts, so you just end up with a pile of dead controllers and LCDs and a bike that doesn't work.

The JST connectors don't need to be waterroof if you stick the controller in a waterproof box or bag.

 

[Nealh]

The controllers with the higo/Juliet type connectors appear to be only used on plug and play kits or OEM bikes for neatness
and ease of fitting for the kit market. After market sales of these are rare to find on a lot of sellers.
The Oxydrive DAS-kits are an example for my Oxydrive's noisy controller although not Bluetooth I want to replace with a nice KT, so when I get around to it I have some soldering to do to swap over the various cable connectors. The pcb I need to remove to fit into my integrated battery frame mount.

 

[anotherkiwi]

The waterproof connectors I have on the 09 battery bottle controller and the only way you can bend the pins is to keep plugging and unplugging the controller. In principle you plug the bits into the controller once and it is done. We all agree that kits with controllers in the battery that are plug and play are neat and tidy. The wires are shorter and less exposed. The BBS0x has an internal controller that is plug and play with watertight o the only complaints I hear are that the wires are too long or too short.

The KT Bluetooth software tells you where the fault is! PAS not working? It shows you on the screen. LCD plug loose idem...

 

[Deleted member 4366]

The KT Bluetooth software tells you where the fault is! PAS not working? It shows you on the screen. LCD plug loose idem...

It doesn't show you why, nor does it give any clues to the other normal problems you get. the Bafang one isn't much use either. The error codes give you some clues, but you can't test anything to see why it's giving you the errors. They're all great until something goes wrong.

What about these communication errors that many members have had? How can you test where the break in the communication is?

 

[anotherkiwi]

Touching wood... The worst I have had is a pulled PAS plug after falling over.