JK BMS DIY power button? Pin out?

[rumdev]

I have several JK BMS B1A8S20P, the silver looking open cased ones, not the earlier black enclosed versions. I’d like to add a power button (I have no screen). I’ve ordered my own switches (non-latching) and some suitable connectors, but am struggling to figure out how to actually make the switch work.

Bridging pins 1-2 of the display connector will turn the BMS off, but I can’t figure out how to get it to come on again with the switch. I read an old thread that mentioned a 10k resistor but adding this didn’t do anything.

Can anyone shed any light on this for me?

 

[rumdev]

 

[rumdev]

@upnorthandpersonal do you happen to have any knowledge on this for the more recent models? ?

 

[upnorthandpersonal]

Have a look here:

esphome-jk-bms/docs/display-port.md at main · syssi/esphome-jk-bms

ESPHome component to monitor and control a Jikong Battery Management System (JK-BMS) via UART-TTL or BLE - syssi/esphome-jk-bms

github.com

 

[rumdev]

Have a look here:

esphome-jk-bms/docs/display-port.md at main · syssi/esphome-jk-bms

ESPHome component to monitor and control a Jikong Battery Management System (JK-BMS) via UART-TTL or BLE - syssi/esphome-jk-bms

github.com

Thank you. Unfortunately shorting pins 1&2 with a 10k resistor does nothing for me. Shorting the same pins with just a wire or switch turns the BMS off instantly, but won’t turn it on again even holding for 5 seconds. So unless I’ve got the pins the wrong way and I’m actually shorting pins 5&6, my BMS is not behaving as described in the link above ?

 

[rumdev]

Have a look here:

esphome-jk-bms/docs/display-port.md at main · syssi/esphome-jk-bms

ESPHome component to monitor and control a Jikong Battery Management System (JK-BMS) via UART-TTL or BLE - syssi/esphome-jk-bms

github.com

Is it pins K+ and K- on that diagram? If so, looks like I indeed had the wrong pins ??‍

 

[upnorthandpersonal]

Is it pins K+ and K- on that diagram? If so, looks like I indeed had the wrong pins ??‍

Yes, that's what I hoped you would see - I wanted to point out they have different pin-outs.

 

[rumdev]

Yes, that's what I hoped you would see - I wanted to point out they have different pin-outs.

Nice one. Yeah it seems I was using the pinout for the older models. I did wonder if I had the wrong pins but didn’t want to risk trying the other two. Ironically I’d been taking that risk unwittingly anyway ?.

Tried it with the correct pins and it works. Thank you very much for your help pointing me in the right direction. ?

 

[Berseker]

I have several JK BMS B1A8S20P, the silver looking open cased ones, not the earlier black enclosed versions. I’d like to add a power button (I have no screen). I’ve ordered my own switches (non-latching) and some suitable connectors, but am struggling to figure out how to actually make the switch work.

Bridging pins 1-2 of the display connector will turn the BMS off, but I can’t figure out how to get it to come on again with the switch. I read an old thread that mentioned a 10k resistor but adding this didn’t do anything.

Can anyone shed any light on this for me?

am i missing something?. why not buy the original cheap jk bms standalone ON switch?..less than 5 dollars

 

[740GLE]

View attachment 178090

What’s the connector pn that’s used for the BMS?

I have a broker connector on my switch.

 

[sillared]

What’s the connector pn that’s used for the BMS?

I have a broker connector on my switch.

740GLE, did you ever find out what that connector is called? My on/off switch port met an untimely demise... *too short of cable* and I have good friend with rockin soldering skills that can replace the port if I can find out what the dang port is and order a replacement...