Swytch Pro/Max yellow battery connector secrets revealed?

[Cisco-man]

There’s a genuine Swytch charger on ebay currently WITH the correct OD connector (currently £12ish buyitnow). Search for “SWYTCH E Bike 2A Charger Adapter New Official Genuine In Box”

 

[Tipidave1]

Iwould like to use my original gen 1 10.2 Ah battery and wire it into the gen 3 mount. Does anyone know how to get the output terminals to go live without connecting it to the original gen 1 controller? I have tried shorting across the 'switch connector'

 

[matthewslack]

I have no Swytch experience, just a dangerous amount of curiosity.

I would be looking at the thing that plugs in to the switch connector, to work out what it does to switch the Swytch battery on... if not shorting out the wires (I'm assuming only 2 in that connector?), does it perhaps apply a voltage, and thereby operate a relay or other kind of switch? Or is it hokey pokey canny bussy?

If that is not possible, the only other option which is only suitable for the sufficiently careful is to open up the battery pack and see what is inside.

 

[Tipidave1]

I have no Swytch experience, just a dangerous amount of curiosity.

I would be looking at the thing that plugs in to the switch connector, to work out what it does to switch the Swytch battery on... if not shorting out the wires (I'm assuming only 2 in that connector?), does it perhaps apply a voltage, and thereby operate a relay or other kind of switch? Or is it hokey pokey canny bussy?

If that is not possible, the only other option which is only suitable for the sufficiently careful is to open up the battery pack and see what is inside.

I am somewhat averse to just open and fiddle… rather hoping to gather some intel ir schematic first

 

[saneagle]

Iwould like to use my original gen 1 10.2 Ah battery and wire it into the gen 3 mount. Does anyone know how to get the output terminals to go live without connecting it to the original gen 1 controller? I have tried shorting across the 'switch connector' View attachment 56255

I'm no expert, but I would have thought "switch" might have been a clue.

 

[Tipidave1]

I'm no expert, but I would have thought "switch" might have been a clue.

I of course tried this but it does not make the output live

 

[matthewslack]

I am somewhat averse to just open and fiddle… rather hoping to gather some intel ir schematic first

Fair enough. For me it depends on how easy it is to open, and whether there is a chance of a very simple answer once I can see inside.

I have to admit to having dismantled many more things than I have mantled.

 

[thelarkbox]

Fair enough. For me it depends on how easy it is to open, and whether there is a chance of a very simple answer once I can see inside.

I have to admit to having dismantled many more things than I have mantled.

how many things re - mantled didnt have bits left over??
#1 rule for dismantling.. Never use a box with bottom flaps to keep screws/washers in on a strip down as something will always find its way under one of the flaps only to be discovered weeks later..

 

[saneagle]

Iwould like to use my original gen 1 10.2 Ah battery and wire it into the gen 3 mount. Does anyone know how to get the output terminals to go live without connecting it to the original gen 1 controller? I have tried shorting across the 'switch connector' View attachment 56255

The Swytch mk1 has a switch next to the charge socket that switches the battery on and off. AFAICS, it's a momentary switch, which means the battery has a smart BMS controlled by a microprocessor. I've not seen that switch in the flesh, so I can't be certain.

The logical thing to do is take the screws out of the case and look inside, which should take less than two minutes, then you have your answer, and at the same time you can check the cell-pack voltages because it could be them that prevent switching on.

 

[Cisco-man]

I’ve just finished modding my wife’s Swytch Max bike so she can have extra (non Swytch) batteries, and still use a Swytch pack if she likes for shorter journeys.
The transistor thing screwed to the back of the Swytch handlebar battery holder is a twin 30A schottky diode (number visible in photo). The red wire between the yellow top connector and the controller is cut, the yellow connector end is brought out to an outer leg of the schottky, and the controller end is brought out to the middle leg of the schottky. The black wire between the yellow top connector is T’ed into, and brought out to an XT60 connector. The + side of the XT60 connector is taken up to the other outer leg of the schottky. An additional battery pack can now be connected to the XT60 connector without fear of upsetting any batteries that may or may not be connected or which maybe in a different charge state.

 

[Cdfghglz]

Hi

I would like to use something like this to control the charge capacity: https://www.aliexpress.us/item/1005005278656856.html?spm=a2g0o.productlist.main.13.667bN88qN88qYo&algo_pvid=d426c673-b8c7-48e5-b134-85a644a4a288&algo_exp_id=d426c673-b8c7-48e5-b134-85a644a4a288-6&pdp_npi=4@dis!USD!2.87!2.87!!!20.71!20.71!@2101e9ec17143727560768493e75bd!12000032464153029!sea!US!850824197!&curPageLogUid=ZFZ5kvXgte9c&utparam-url=scene:search|query_from:&gatewayAdapt=4itemAdapt

The device however takes power from the "detection end" (battery), which the swytch battery pack does not seem to provide even when I press the indicator button.

Do you think it would be a good idea to short the inner flat pins and charge via the outer ones (normally the power output)?

 

[Cisco-man]

With nothing plugged into the battery pack the output of the battery pack isn’t presented to the outside world - for safety when carrying the battery in your backpack, etc. Shorting the two inner flat pins on the yellow plug turns on the output of the battery pack and presents the power to the outside two flat pins. I’ve got no knowledge of what circuitry is inside the battery pack to turn the output on and off, so I believe that back-feeding the battery output pins (through whatever circuitry is there) would be a bad idea. Doesn’t get my vote!

 

[Cisco-man]

Using the “reverse O-D” IC5 type connector in the centre of the battery yellow connector (that you normally charge through) might be possible way forward for you, but again it probably will have protection circuitry.
At £300+ a go, I wouldn’t be risking blowing your pack up just for a “nice to have” modification!

 

[Cisco-man]

Final thoughts (I promise!). The Swytch charger is very good quality and is trustworthy. Maybe do what I have done and put a connector in the charging cable that allows you to have a voltmeter inline that’ll give you a good indication as to the charging progress. secondly, I use a 240v count-down timer (eBay) in the charger wall socket. I can tell it to charge for fixed periods of time, and when I forget to check how it’s going, it has turned it off automatically at a reasonable time interval.

 

[Cdfghglz]

Thank you for your insights.
I want a zero cognitive load solution, setting a timer is not an option for me.
Well I happen to have 3 air packs atm. I was mentally ready to lose one when I was reworking it to 21700 batteries. All went well so I mentally still have one to break ;-). I feel like the worst case is i blow the BMS, which should not be a big deal to replace with a different one.
I am still waiting for a datasheet about the BMS from the producer. I will let u know once I have any news.

 

[Cdfghglz]

I have not heard from the producer so I decided to risk the charging on a "turned on" Air unit - tl;dr: it works.

I started a little more carefully with a power source at 0.1A. All went well so I ended up with this test setup :-D



Interesting note: despite the charging pins reporting identical voltage with the outer flat ones when "on" they could not turn on the XH-M604. Swytch must have protected the charging pins somehow inside the yellow connector, since there are only 4 cables from the BMS.

 

[Cisco-man]

I’m pleased it worked for you - it all adds to our knowledge. The puzzle for me though is why then have separate connectors for putting power into the battery (the OD connections), to taking power out on the outer flat pins, if everything can be accomplished via the flat pins.

 

[StuartsProjects]

OK, sounds like you found a way of 'forcing' an external charge ?

Whilst that might work, what are the exact implications ?

Given the issues there can be with charging eBike batteries, if you have a setup that does not behave in an expected manner with regaurds to charging, you would want to be really really sure that what you are doing is appropriate and safe.

This yellow connector is the key to the understanding, what is inside it, if there was nothing in there then why would there be any issues with connecting a standard charger ?

 

[saneagle]

I’m pleased it worked for you - it all adds to our knowledge. The puzzle for me though is why then have separate connectors for putting power into the battery (the OD connections), to taking power out on the outer flat pins, if everything can be accomplished via the flat pins.

It's a safety measure to stop the pins shorting when you carry the battery in your pocket or bag, otherwise a loose 10p coin would start a fire there.

 

[Georgezx9]

Hi all thinking about doing this on my wifes swytch max, with battery on the front, due to terrible range.
Based on what has been said, I need to have the standard battery fitted as well, or the outer ports dont do anything to the other controls, in effect fitting a second 36v battery and having both power the bike