Of the two attached piccies, I suspect that one is of the battery condition monitor - they are both in the right place (I guess) on top of the battery measuring something, presumably voltage, across the battery terminals.

I've googled the part numbers and am none the wiser, except that they can cost a bomb.

My favourite guess is that its the white one, attached to the battery -ve terminal, and that the black one is simply the main cable from the positive supply.

Can anyone shed any light, and also point me to where I can find its datasheet/operating parameters?

Thanks - Richard.

Car is a 2020 Focus MK4 120ps diesel ST-Line.

As my German friend will tell you in his YouTube video it is White unit that is the BMS which monitors the SOC.

Watch the video and he explains (sub titles if you don't speak German) at [2:33] about the sensor and that some cars have the wrong sensor fitted.

 

Thanks Unofix - I wanted to see what/where it was primary because I've read such a lot about what problems it can cause on earlier versions of the Focus on this forum. Its obviously not under the washer bottle(!) and is probably easier to protect from water ingress in the longer term.

I also wanted if possible to see how it works - whether it evaluates battery condition and sends the result back to the cars ecu, or whther it simply sends the raw data (e.g. voltage) back for the ecu to evaluate. I doubt however that Ford will have publicised this data any more than they do the content of software updates, at least as far as I can find out!

Cheers - Richard

37 minutes ago, RMurphy195 said:

because I've read such a lot about what problems it can cause on earlier versions of the Focus on this forum. Its obviously not under the washer bottle(!) and is probably easier to protect from water ingress in the longer term.

It is the BCM [Body Control Module] that suffers from problems with water ingress caused by the screen wash pump. The BMS [Battery Monitor System] is practically bomb proof, it is hermetically sealed, you could jet wash it if you like. It's not a very clever unit, just a calibrated current shunt which can also detect the flow of current in to, or out of, the battery.