reention battery question

[QWIC]

My Qwic ebike (dutch brand) works with the reention downtube battery. The connector carries two extra wires (apart from the + and - wires) which have a slightly lower voltage than the battery itself (+37V with fully loaded battery at 42V). Inside the battery this signal comes from the BMS, I gues it's some kind of battery gauge?

I've tried connecting a battery without these two extra wires coming from the BMS and the bike will power up, but it gives an empty battery signal. this means I can only buy batteries from Qwic (and they are, of course, ridiculously overpriced).
Any idea what this signal could be and how I could circumvent this to use any battery with my bike?

 

[Gionnirocket]

It's probably communication between the battery BMS and the motor's controller. Without using the same BMS not sure you can get around it working as the stock battery.
You could just wire in a simple voltage display to monitor battery capacity

 

[QWIC]

The voltage display is a great idea, but I forgot to mention the most important part: the bike powers up, but the motor doesn't work without the extra signal from the battery.
I gues the only option is changing the controller? It's a TDCM motor so I gues it should work with a phaserunner controller. And buying a phaserunner controller with a no brand battery would be cheaper than buying the branded battery!

 

[Gionnirocket]

The voltage display is a great idea, but I forgot to mention the most important part: the bike powers up, but the motor doesn't work without the extra signal from the battery.
I gues the only option is changing the controller? It's a TDCM motor so I gues it should work with a phaserunner controller. And buying a phaserunner controller with a no brand battery would be cheaper than buying the branded battery!

I would confirm with phaserunner but that makes sense.

 

[Blurp]

The 1 and 2 pins on the qwic batteries actually send a 50hz 1.36V peak to peak sinusoidal signal to the bike wit a full battery. I reckon either the amplitude or the frequency of this signal is used to transfer the battery SOC to the bike, which in turn determines if the motor can be engaged or not.

 

[Chevy]

Hi all,

Is there a bms on the market somewhere, which has the same signal? So I can replace the bms?