Swytch kit: compatibility with non-Swytch components?

[cheesemonkey]

Hello everyone,

Overall, I've been a happy customer of Swytch kit (got PRO kit in Oct 2020), I would have not got into pedelec bike without it. After ~4,000miles of usage, 3x replacement battery packs (all received within one year warranty period), I've ran out of working battery packs (all failed due to fried controller). Shame that there's no way to source the replacement controller other than via Swytch customer service (a topic already covered elsewhere).

I'm now looking to see if I can still keep the front motor hub and find a kit (battery, controller, display) that is compatible. The hub itself doesn't have much info other than engraved "Swytch" with some numbers (no indication of the actual hub manufacturer).

Has anyone attempted plugging non-Swytch components to keep the bike going?

If not then it'll mean getting a whole conversion kit possibly from Woosh bikes. I prefer not to throw things away if they can still be used...

Thank you and happy cycling!

 

[peterjd]

I don't see why not. I have only used the Swytch originated controller (replacement from Swytch used on Gen.1 model with Hall bypass lead). The batteries I use are a Yose 10.5 Ah and various Bosch (genuine and compatible) 2.5 and 5Ah batteries when only lower capacity required, usually located on or in rear pannier rack or bag.

 

[JCRollins]

I am interested in doing something similar and chanced upon your request when searching for answers

I found this forum which seems to have quite a lot of technical advice :

Endless Sphere DIY EV Forum

DIY forum for Ebikes, Scooters, Motorcycles, ATVs, other EVs

endless-sphere.com

On a quick look at it, I thought this might take you (& I) some way towards working it out:

Motor not running, are my components compatible?

I had a Swytch bike kit but the battery/controller pack got stolen. I decided to try to buy a separate controller and battery to be able to use the existing motor. I thought I got all the required elements but when I put it together, the motor does not run. Here is what I have: Original Swytch...

endless-sphere.com

I'll keep digging around for anything further over time and if I find anything update you

 

[Nealh]

Hub motors are nothing special in that they are generic three phase and mostly today sensored, if the hub motor cable is a 9 pin julet type ( show a pic to confirm) then yes simply buy a new controller paired with a new display form the same supplier. If you want speed control then any of the cheap £30 buys will work, however if you want a much better ride experience with varying levels of current control (power) then buy a Kt controller and display for approx. £80 - £100.

Any two wire generic battery will work so you have as much choice as you like.

 

[cheesemonkey]

Thanks both, especially JCRollins for the second link - that's exactly what I'm trying to do.

There are some numbers on the motor hub:
Switch
11 digit number that I assume is a serial number (so I won't put on here)
100SX-6XX-36H-S

Bit of Googling tells me that:
100SX could mean Aikema (AKM) 100SX hub
6XX - no idea
36H - 36 spokes
S - no idea

So at least I know that the hub is likely to be a generic Aikema 100SX (it is indeed for 100mm fork). In theory the 9 julet pin (based on Swytch website) should be able to communicate with any controller and display?

I also know that Swytch controller is LSW1452-1-6F (36V, max 12A, rated 6A, protection 31V, throttle 1.2-1.4V). There's a replacement in Aliexpress but another thread on here rendered not a wise purchase.

JCRollins' second link mentions controller KT 36/48ZWSR-ffF02 and display KT900s. This is a minefield for me - what are the differences between all the controllers and displays from KT? Also the original poster couldn't get the Swytch pedal assist sensor working on KT but the walk test was successful (guessing a KT PAS is needed to work instead of Swytch supplied PAS).

This is a good step further for me. I'm now more confident getting a KT kit (but which one exactly? and battery?) to salvage teh Sywtch motor hub.

Any advice on which controller/display kit + battery set-up would be very thankful.

Thank you and happy cycling.

 

[Nealh]

Hub is aikema 100sx.
Controller is lishui , the controller and display often need paring up via programming.
It best to simply use the well regarded KT systems to replace any controller for ver sitility & compatibility issues.

 

[cheesemonkey]

Thanks very much Nealh,

KT (kunteng) seems to have lots of different models for controller, display and PAS.

How do I go about finding the right combination of controller, display, PAS and battery unit to work with Swytch's 100sx motor hub?

Where do I begin with the search?

I am completely out of my depth about this so any help or guidance would be very thankful.

 

[Nealh]

One can use any KT controller or lcd display , they will all be compatable if the connector are the same so buy from the same seller. There are few exceptions where some companies go down the custom route using their own software but these are far and few between.

The 100sx will be suitable with a 15 or 17a controller and any lcd. The favourite displayis the lcd3 though there are others you can use if you like something else. The smaller lcd4 size wise is nice but I had some minor issues with mine as have afew others. Buttons not always working correctly and speed corrulation not always correct.

I use topbikekit for my KT stuff or use a couple of Aliexpress sellers saved in my account, the most issues that arise are simple ones like not having the correct P or C parameters set in the settings . They are easily sorted with forum help.

 

[Nealh]

For controllers I now use the 9 mosfet ones as they have more mosfets and handle heat better then the 6 mosfet controllers , but one may be constrained by the space available to fit one. I opt for a 22a model and simply reduce the current parameter via the display settings.
For PAS it depends on your current BB as to which is best, I prefer the simpler two piece disc and sensor behind the chain wheel/s.
The other main issue is whether to opt for W/P wiring or the older SM block connector wiring, the latter is the obvious and easiest for fault finding for a diyer esp if it is contained in saddle bag or under bar bag. One can fault find the W/P wiring but means one will need to make up custom Y leads ( for a couple of £'s) to carry out the finding.

Show us your bike for recommendations.

The thing with KT if not a custom set up from a third party is almost total compatibilty between the two main component parts which are display and controller , they need no programming and should work straight out of the box.

 

[AGS]

You will probably have a compatibility issue with all of the connectors to the controller. When I modified my Greaser I bought a JST connector kit from eBay so I could interface the existing wiring to the KT controller. This is what NealH is referring to as SM (small block) wiring as opposed to W/P (water proof) wiring. But all of my connections are relatively waterproof inside the battery covers.

I also changed the hall sensor plug on the controller from molex to JST. This is what Grin Technologies do on all the controllers they sell. But they are Canada based, so I didn’t get my controller from them. I just used followed the wiring schematic on their website for the hall wires into the JST connector.

Also you will need to consider how you are going to connect the battery and phase wires. I am currently using one of those yellow 5 way terminal blocks, but I have read that people often have issues with them overheating and melting, so I am keeping a careful eye on mine.

Nealh advice is good regarding buying the next size up controller than you need. It costs a little bit more, but won’t be operating close to maximum capacity so it should be more reliable. And then adjust the C5 setting to reduce the maximum current.

Oh and as for PAS not working, mine ran backwards when I tested it, but the KT controller has a function to reverse the PAS using the C1 setting to save messing around moving the sensor to the opposite side.

I have attached an image showing the sort of wiring that you will have to contend with on KT controller.

So there are several things more to consider when you are doing a component build rather than buying a complete plug and play kit. And you will probably kiss goodbye to any warranty claim if your controller fails after you have hacked the connectors about.

 

[cheesemonkey]

Thank you both for your advice!

Realistically, I don't have the time (with two young kids and full-time job on site) to explore all the options and face the risk of things not being compatible. I'm effectively just keeping the 100sx hub motor from the Swytch kit and replace everything else (though it would be nice to be able to use Swytch batteries; I have two of them and a few spare Amass XT30 terminals). It's all quite over my head.

I wonder is Woosh bikes will be able to give advice / supply a set without the hub motor.

 

[Nealh]

If your motor cale is 9 pin then here is a
9 mosfet Kt controller kit with or without integrated e -brake levers.
Simply select the kit from the thum nail boxes #6,7 8 or 9.
Waterproof Connector Ebike Controller 36v 48v 500w Electric Bicycle Controller 22a 9 Mosfet Compatible Kt Lcd3 Lcd4 Lcd5 Display - Electric Bicycle Accessories - AliExpress

If you want the smaller 6 mosfet controller then choose option #2 or 5.

Kt Ebike Controller Waterproof 250w 350w For Bafang Hub Motor 36v 48v Electric Bike Controller With Lcd3 Lcd4 Lcd5 Display - Electric Bicycle Accessories - AliExpress

 

[Nealh]

Alternatively just select items needed from the drop down boxes from TBK.
T09S 36V/48V500W 22A KT Sine Wave Controller For ebike [T09S KT 9Mosfers Controller] - $26.60 : Zen Cart!, The Art of E-commerce (topbikekit.com)

 

[cheesemonkey]

Thank you nealh for the links. I'm getting my head around.

Another challenge I realised is the battery removal for security and charging. I'll need a waterproof container for the controller and a convenient way to disconnect the battery and the rest of the set up.

Salvaging the Swytch power pack bag is unlikely:
1. a new controller would not fit in it (its a very tight space in the pack).
2. power cable to Swytch battery and set of cables out to PAS, display and the motor would need to be connected directly, bypassing Swytch handlebar bracket (which works as a docking mechanism for easy removal of the battery pack).

More thoughts in to this plan...

 

[cheesemonkey]

ok had some more time to do some research.

Thanks to Nealh, I'm looking at topbikekit website for the controller.

SOLUTION 1 is to get a controller kit and try to get Swytch battery to connect:
Two choice of controller kit that I see:
T06S 24V/36V250W 15A KT Sine Wave Controller with Julet Waterproof Connector [T06S controller Waterproof Plug] - $26.60 : Zen Cart!, The Art of E-commerce (topbikekit.com)

T09S 36V/48V500W 22A KT Sine Wave Controller with Julet Waterproof connector [T09S controller waterproof plug] - $33.25 : Zen Cart!, The Art of E-commerce (topbikekit.com)

Adding the options (for simplicity; KT LCD5, 9pin 60cm extention, no brakes or throttles, KTD12L PAS), T06S comes at $66.40 and T09S comes at $73.50.

The differences I see are:
T06S is 6MOSFET (I don't know what MOSFET is so I need to learn about that) ,250W, max 15A
T09S is 9MOSFET and 500W, 22A.

Comparing the two, I'm assuming T09S is the go for and still compatible (though it's for 500W and max 22A?) with Swytch motor 250W (controller was max 12A; I opened one, only to see that inside was packed with some sort of silicone / glue and no way to investigate further).

Happy to do some soldering for battery connection to Swytch batteries that I have (Amass XT30 terminals; Have some spare terminals from previous attempt to repair).

Issue still is the battery removability. I could get a controller box from topbikekit (or somewhere else) and have the battery cable to the Swytch powerpack. Or get something like this (similar size to the Swytch power pack): 36V10AH Samsung INR21700-50E Li-ion Battery Pack+Bag [36V10AH Samsung 21700+Bag] - $151.05 : Zen Cart!, The Art of E-commerce (topbikekit.com)

SOLUTION 2 is to get a downtube battery kit (i.e. ditch everything form Sywtch kit but the motor):
Or I came across Hailong (1 or 2) integrated controller battery holder + KT LCD5 & PAS for £86.95 (a website): 36v 250w hailong built in kt controller set with Julet connector-Greenbikekit.com BBS, ebike batteries, Bafang M620, Bafang M600, Bafang M500, Bafang M510, KT controller with display-GreenBikeKit.com. I won't be able to use the Sywtch batteries but could get a downtube battery pack (+$150-200 for 10Ah battery?). Shame that Swytch batteries can't be used (I have two; 5.2Ah which is enough for my current use of 2.5mile nursery run with two kids on the trailer).

Can either solutions work? What challenges will I face?

 

[AGS]

You may run into problems trying to connect the switch battery to anything else apart from a switch controller. It’s integrated into the connection module and I think it’s potted, so unless you can dig out the potting and remove the controller to access the battery connections inside the controller you won’t be able to interface your battery to an aftermarket controller.

 

[cheesemonkey]

You may run into problems trying to connect the switch battery to anything else apart from a switch controller. It’s integrated into the connection module and I think it’s potted, so unless you can dig out the potting and remove the controller to access the battery connections inside the controller you won’t be able to interface your battery to an aftermarket controller.

Thanks for the comment AGS. As far as I can see inside the power pack, Lishui controller and the battery can be separated (Amass XT30 terminals). Out of curiosity, I dismantled one power pack before (this one had XT30 completely melted due to poor soldering at factory) and the battery unit is encased in a plastic box (with "warranty void if seal broken" seal). Inside the plastic box is the actual battery cells, which is wrapped in blue soft plastic. There are few cables that come out of that (XT30 terminals and another plug for charging point). There's some potting (I had to look up what that meant) over the cables, terminals and corners of the box to secure the battery cells but it wasn't hard to cut the unit loose.

The battery cell and the cables that come out of it looks like this (not the exact model or size, but as an example):

So I'm guessing, as long as the power terminal from a controller is XT30, the battery unit can be connected to a controller and charged again?

 

[Nealh]

XT 30's aren't usually used for ebikes , the XT60 is the most common default option used.
As long as the switch battery is a generic two wire option an dit can be used as a stand alone item then it will work with any KT or generic type controller.

The mosfets are used as phase voltage swtiches , 6 fet 2x fets per phase and 9 fet 3 x fets per phase. SImply the 9 fet cna handle more heat due to higher current so less chnace of thermal heat cut out.

I use to use 6 mosfet KT at 20a but suffered with thermal heat cut out at 17 - 20a when climbing involving slow speed, so opted for 9 mosfet to overcome the heating issue.
For most use 6 mosfet is fine , it is only if using at the upper reaches of current rating above 15a continuous for a while.

 

[Nealh]

Controller saren't wattage rated it is just typical of china listings, the only thing of importance is the controller current rating and that your battery continuous discharge rate can cover above the controller rating. The advantage of KT is one can reduce the current rating by some 5a or 50% of the rating dependant on the version supplied.

 

[cheesemonkey]

Thanks very much Nealh,

The actual battery unit in Swytch kit (or at least the ones I have; I've seen different kinds on Google Image) seems to be a generic blue wrapped cell unit with red&black wire battery (+the input socket for charging) so I'm convinced it can be connected to a controller. I think Swytch uses XT30 for keeping everything as small as possible. Inside the powerpack is so crammed it's nightmare each time to investigate the controller or the battery.

Thanks for the MOSFET explanation; that makes sense as my first battery pack fried in a hot day (27c I think it was) going up countryside hills. I also experienced cut outs in last year's heatwave. I believe Swytch controller is 6MOSFET (based on the physical size of the controller and max 12A capacity).

A bit more investigation and I found out that the reason for one of the powerpacks I have is failing is the poor connection between the powerpack and the handlebar mount. The metal pins weren't connecting well; a simple pinching of the powerpack pins rectified this and I have, at least for now, a functioning set-up. The other powerpack doesn't even turn on so that's another issue. I seem to have bought some more time for now but will continue to look for solution to move away from Swytch components.