Swytch Max biker looking to add an extra battery

[saneagle]

Hi John Bucklebury, I am trying to do the same thing. Did you get to any conclusion? I will try to purchase the XT60 or XT30 connectors and adapt them to check if they fit

If I were trying to solve the problem, I'd be looking inside the battery receiver thing to see how the controller is connected. There might be an easier way to connect a battery to it. At least you'll be able to find out if the outer connectors do anything.

 

[theabsurdman]

Could somebody with a Swytch Air or Max battery who knows what they are doing please put a voltmeter negative probe in the discharge slot numbered 1 in my attached image below and report the measured voltages on the positive probe across slots 2, 3 and 4? Include any negative signs and be very careful not to short any of the slots through the probes!

Thanks.

 

[Cisco-man]

Hi.

I’ve just found this thread and it seems to be about exactly what I’m intested in - adding other battery packs onto the Swytch Max set up. I’ve got a number of Makita 18v packs for my power tools and I would like to use them for my bike by having two Makita batteries in series - giving 36 - 40v at 6Ah capacity.

As a newbie - both to this forum and to pedelecs - I‘ve no wish to upset anyone by either gate-crashing another thread, or spouting off a load of b*locks. I’m nevertheless keen to try and glean as much info I can from this forum about adding different batteries.

As I posted on the wrong thread, if you measure the charge connector in the middle you get full battery voltage (around 42v). If you measure at the output slots you get 32v. When the battery declares that it’s flat, the battery is 32.6v. I Accept that my crude analysis of this may well be wrong, but in my experience as a humble electronics engineer I would feel that there is a power transistor circuit in the battery housing taking it down to 32v in order to keep the feed at this voltage, and the 0.6v is the voltage drop across the semiconductor junction.

Any thoughts?

 

[saneagle]

Hi.

I’ve just found this thread and it seems to be about exactly what I’m intested in - adding other battery packs onto the Swytch Max set up. I’ve got a number of Makita 18v packs for my power tools and I would like to use them for my bike by having two Makita batteries in series - giving 36 - 40v at 6Ah capacity.

As a newbie - both to this forum and to pedelecs - I‘ve no wish to upset anyone by either gate-crashing another thread, or spouting off a load of b*locks. I’m nevertheless keen to try and glean as much info I can from this forum about adding different batteries.

As I posted on the wrong thread, if you measure the charge connector in the middle you get full battery voltage (around 42v). If you measure at the output slots you get 32v. When the battery declares that it’s flat, the battery is 32.6v. I Accept that my crude analysis of this may well be wrong, but in my experience as a humble electronics engineer I would feel that there is a power transistor circuit in the battery housing taking it down to 32v in order to keep the feed at this voltage, and the 0.6v is the voltage drop across the semiconductor junction.

Any thoughts?

Look on the controller side connector. There are just two wires - red and black. That means that the controller is completely dumb regarding the battery. Inside the box is a normal controller, probably KT as the LCD is the same as KT LCD4, but there are a load of clones. The controller is dumb and works on 36v (42v-31v) There wouldn't be any sense in restricting the battery voltage to 32v. it would be a lot easier to restrict current. Put a 36v charger to the controller or any opposite pair of outer pins on the connector and you'll see whether the bike works, which it almost certainly will. Make sure you get correct polarity.

I don't understand you guys at all. It's a very quick job to open the controller box and look inside. Then you get all the answers. Instead, you waste everybody's time in making trumped up theories and asking unanswerable questions when you have the answer right in front of you. If you're two scared to undo two screws or whatever it is, you shouldn't be messing around with these things.

Please, for the love of god, open the 'kin box and show everybody what's inside.

 

[Cisco-man]

Look on the controller side connector. There are just two wires - red and black. That means that the controller is completely dumb regarding the battery. Inside the box is a normal controller, probably KT as the LCD is the same as KT LCD4, but there are a load of clones. The controller is dumb and works on 36v (42v-31v) There wouldn't be any sense in restricting the battery voltage to 32v. it would be a lot easier to restrict current. Put a 36v charger to the controller or any opposite pair of outer pins on the connector and you'll see whether the bike works, which it almost certainly will. Make sure you get correct polarity.

I don't understand you guys at all. It's a very quick job to open the controller box and look inside. Then you get all the answers. Instead, you waste everybody's time in making trumped up theories and asking unanswerable questions when you have the answer right in front of you. If you're two scared to undo two screws or whatever it is, you shouldn't be messing around with these things.

Please, for the love of god, open the 'kin box and show everybody what's inside.

Thanks Saneagle.

What you say is exactly what I want to hear from this forum - the voice of experience. I shall take onboard what you say and learn.
I was hoping that someone would offer up some photos of what is inside the controller box. I’m no coward when it comes to opening things up to explore, but my kit is currently under warranty and I don’t have enough money to break it needlessly. I want to set myself up so that I’m ready to proceed when the warranty expires.

 

[saneagle]

Thanks Saneagle.

What you say is exactly what I want to hear from this forum - the voice of experience. I shall take onboard what you say and learn.
I was hoping that someone would offer up some photos of what is inside the controller box. I’m no coward when it comes to opening things up to explore, but my kit is currently under warranty and I don’t have enough money to break it needlessly. I want to set myself up so that I’m ready to proceed when the warranty expires.

Everybody that has a Swych kit is asking each other the same questions, but none of them will give the answers, and they all have the answers in front of them. Until someone does open one, all we can do is guess, though I'm pretty sure I'm right.

 

[Solarbake]

Look here I have some answers works a treat on external 36 v battery’s or makita power tool battery’s

21700 10 Ah Battery Build: Peer Review

Hi, I have completed a 10 Ah battery and, as well as my own learning, would appreciate thoughts and improvement suggestions relating to safety, performance and electrical maths. Key points: 10S2P using branded 5mAh cells Daly 20A BMS Waterproof Common Port 30A Internal Fuse 0.15mm nickel...

www.pedelecs.co.uk

 

[Cisco-man]

I shall read and absorb! I spent a long evening yesterday reading through as many posts as poss. I did find a post that had a photo of the inside of the Swytch Pro/Max battery holder. It confirms what Saneagle says - that there is just two wires (red and black) coming down from the yellow connector, to a LSW1542-1-10-1E controller (by isdzs.com). Input to this controller being a nominal 36v at 6A constant/12A max, LVP at 29v, throttle adjustment 1.2v-4.4v.
I still need to bottom-out whats going on with the actual yellow connector. I accept that there are only two wire coming from it, but (ignoring the two charging pins) there are strange voltage readings across the four flat connectors (unless my voltmeter is bug*ered). Could this be some form of anti-tampering detection e.g. if you connect up wrong, then something in the connector blows - or is my imagination going off on tangents again!

Thanks all for your input.

 

[saneagle]

I shall read and absorb! I spent a long evening yesterday reading through as many posts as poss. I did find a post that had a photo of the inside of the Swytch Pro/Max battery holder. It confirms what Saneagle says - that there is just two wires (red and black) coming down from the yellow connector, to a LSW1542-1-10-1E controller (by isdzs.com). Input to this controller being a nominal 36v at 6A constant/12A max, LVP at 29v, throttle adjustment 1.2v-4.4v.
I still need to bottom-out whats going on with the actual yellow connector. I accept that there are only two wire coming from it, but (ignoring the two charging pins) there are strange voltage readings across the four flat connectors (unless my voltmeter is bug*ered). Could this be some form of anti-tampering detection e.g. if you connect up wrong, then something in the connector blows - or is my imagination going off on tangents again!

Thanks all for your input.

The only way to know would be to open the battery. It could be a bad solder joint. Another idea would be to put a small load on the 32v to see if it collapses. If it's switched off by a MOSFET, you can get some minute amount of charge bleeding through, and the voltage you measure depends on the impedence of your meter.

With only two wires on the controller side, I can't see how the battery could have any internal switching, and it wouldn't make sense that the other terminal is switched on.

Can you give me a link to the picture of the inside of the battery holder? i've searched endlessly and never found one.

 

[Cisco-man]

The only way to know would be to open the battery. It could be a bad solder joint. Another idea would be to put a small load on the 32v to see if it collapses. If it's switched off by a MOSFET, you can get some minute amount of charge bleeding through, and the voltage you measure depends on the impedence of your meter.

With only two wires on the controller side, I can't see how the battery could have any internal switching, and it wouldn't make sense that the other terminal is switched on.

Can you give me a link to the picture of the inside of the battery holder? i've searched endlessly and never found one.

I should have made a note of which thread it was I found them on. I have saved the photos. Do you think the owner of the photos would mind if I reposted them? I can’t face trawling through all the threads again. It’s all for a common cause, and they can claim ownership for them on this thread!

 

[Cisco-man]

I should have made a note of which thread it was I found them on. I have saved the photos. Do you think the owner of the photos would mind if I reposted them? I can’t face trawling through all the threads again. It’s all for a common cause, and they can claim ownership for them on this thread!

Found the thread. It’s”Swytch kit: compatability with non-Swytch componenets” started by Benjahmin, and photos posted by Quintessence.

 

[lenny]

https://www.pedelecs.co.uk/forum/threads/swytch-kit-compatibility-with-non-swytch-components.44851/

 

[Cisco-man]

So the “bike side” of all this is understood. You take a 36v battery of whatever make, and you tap into the red and black wires inside the controller (confirmation would be appreciated!).
although not my worry, there is some weird sh*t going on inside the Swytch battery. I’m pretty handy with electrics, so this is bugging me that I just look stupid at the mo! On the charging pins of the battery pack you get full voltage of the pack - steady and stable. We can ignore these because they don’t connect to the bike in any way - they are just for charging with the stand-alone charger. Measuring (again) on the four flat connections that do connect to bike, I get various, very fluctuating readings on my voltmeter. Nowhere can I find a full-voltage, steady reading. I don’t want to load any of these connections up until I know whats going on, but it’s strange. Either way, my goal is only to be able to add alternative batteries to the Swytch bike, such as my numerous Makita packs, so the Swytch pack can be as weird as it likes!

 

[saneagle]

So the “bike side” of all this is understood. You take a 36v battery of whatever make, and you tap into the red and black wires inside the controller (confirmation would be appreciated!).
although not my worry, there is some weird sh*t going on inside the Swytch battery. I’m pretty handy with electrics, so this is bugging me that I just look stupid at the mo! On the charging pins of the battery pack you get full voltage of the pack - steady and stable. We can ignore these because they don’t connect to the bike in any way - they are just for charging with the stand-alone charger. Measuring (again) on the four flat connections that do connect to bike, I get various, very fluctuating readings on my voltmeter. Nowhere can I find a full-voltage, steady reading. I don’t want to load any of these connections up until I know whats going on, but it’s strange. Either way, my goal is only to be able to add alternative batteries to the Swytch bike, such as my numerous Makita packs, so the Swytch pack can be as weird as it likes!

What I'd do is run the controller and the connector wires outside the box and fit XT60 connectors. Then, whenever you want, you can connect any 36v battery you want or the Swytch battery. The controller doesn't care what 36v battery you use. It's a standard 36v controller that you find on any 36v ebike.

Whatever is going on in the Swytch battery is irrelevant. The controller doesn't see it. Maybe it's some system to disable the pins when you take the battery off the bike for safety reasons. My guess is that each pair of pins on the controller side are doubled up. You can do a continuity test with a meter to confirm. Then the Swytch battery will only give power when one or each corresponding pair are shorted.

Thanks both for the photos. They make it absolutely clear.

 

[saneagle]

If anybody else opens that box, please measure the controller. It looks long and thin. I'd like to know whether a standard 15A KT one would fit in there because sooner or later people will be asking about replacement controllers.

 

[Cisco-man]

If anybody else opens that box, please measure the controller. It looks long and thin. I'd like to know whether a standard 15A KT one would fit in there because sooner or later people will be asking about replacement controllers.

My next step (so’s not to invalidate my warranty), is to (after suitable continuity testing) connect my 36v Makita battery set-up to the flat contacts of the handlebar battery holder (that contains the controller). I think AMP connectors will do a reasonable job, considering that its fairly high currents going on. I shall then cable to the back of the bike and whatever batteries I’m using (Swytch or otherwise) will be on the back pannier permanently. I don’t like all that weight on the front handlebar With a battery hanging on it.

 

[AGS]

It should be 24mm x 40mm x 86mm, but worth confirming with a real measurement.

Pardon our interruption...

 

[saneagle]

It should be 24mm x 40mm x 86mm, but worth confirming with a real measurement.

Pardon our interruption...

Thanks. 40mm is very narrow. Too narrow for KT. Blast!

 

[AGS]

How much do these kits cost? They are very basic.

 

[Nealh]

They are basic and very dear for what you get , one is paying all that money for that yellow quick connector , handle bar bag and the delights of tiny ah battery that is approx. £100.
We have said it from the start one can get the smae kit parts for half the price, if wanting a tiny battery in a bar bag it isn't hard to do and one can simply use an anti spark XT90 for the connection.