JK bms LCD - what is the attached ring?

[mangchi]

Hi All, I bought a couple JK 8s BMS in January of 2022. I'm about to assemble a set, opened the box containing the mini LCD and there is this big black ring attached to the LCD display. See pictures below. What the heck is this? Thanks!

 

[packrat1969]

Hi,
Sorry, I have no experience with JK BMS units, but is there any chance it could be some kind of current-sensing coil? Post more pictures, especially of any connectors that might attach to the BMS or display.

 

[Texas-Mark]

It's a current sensor.

 

[mangchi]

So am I supposed to put the ground wire through the hole? Feels stupid because you would typically mount the LCD display outside of the battery box. Would there be a problem if I just left it alone? I would be using the LCD for the just switch and quick visual confirmation that the pack is operational. Victron Cerbo screen would be mounted in a more accessible location and would be the primary point for monitoring.

Looking at Minerals aliexpress store (and other storefronts), it seems they aren't selling these anymore. The ones for sale look identical minus the current ring. So were these very early production models when they just start making these mini LCd screens?

 

[mangchi]

Hi,
Sorry, I have no experience with JK BMS units, but is there any chance it could be some kind of current-sensing coil? Post more pictures, especially of any connectors that might attach to the BMS or display.

All the connectors can be seen in the second pic. It connects to the 486 port on the bms, just like all other LCD connections to these bms's. FYI, mine is the one without the heater port, bought in Jan of 2022.

 

[Sky-HHI]

I found one on Aliexpress and the review said "Small display for handlebar mount. Good brightness but no settings possible". Looks like it is a handlebar mount for an ebike. Is there a set screw to attach it to a handle bar?

 

[mangchi]

I found one on Aliexpress and the review said "Small display for handlebar mount. Good brightness but no settings possible". Looks like it is a handlebar mount for an ebike. Is there a set screw to attach it to a handle bar?

This makes a lot more sense. Yeah, there is a set screw. So it looks like I can just saw off that part.

This LCD came with 200A BMS, 8s. Who would mount 8 high current cells on a bike?!?!?

 

[Texas-Mark]

Looks like it is a handlebar mount for an ebike.

Wow, I would have never guessed.

 

[TorC]

It just disassembles from the display. I forget how off the top of my head, but it was pretty easy to figure out.

 

[Tiziano]

HI
I am also interested in JK-BMS, mine is B2A8S20P.
As far as I could see there are two displays available, one specific for some models and another for others.
None have a current sensor though, there is in the BMS.

 

[upnorthandpersonal]

Who would mount 8 high current cells on a bike?!?!?

The screens were just adapted to fit their entire range of BMS.