For Those that have relocated their battery . . .

[cidsamuth]

With the motor swap on my stripped track car, I relocated the battery to the back. The weight distribution change was nice, but it also allowed me to put an effective kill switch on the car.

Anyway, for those who have done it, what did you do with the Battery Monitoring System sensor on the negative battery post? For a track car, I'm hoping it's fine to simply unplug and delete it. But, if necessary, I'll run the wires all the way to the battery in the rear . . .

 

[thecman02]

I'm looking into the operation theory of the BMS. On most Fords its at least measuring current flow. I'm not sure if the Fiesta BMS also can measure battery temp. I think unfortunately you will want to extend wires.

Or if you want to get tricky you can figure out a normal operating range underload and come up with a plug in BMS delete. We'd need to find diagnostic information on what module the BMS reports too. I'm assuming it would go to BCM (Body Control Module). BMS values are important to numerous systems on the car. If charging output isn't correct you'll have unintended consequences. Off the top of my head you might have a situation where electronic power steering is sent to a reduced output mode which could be bad.

 

[cidsamuth]

Hmmmm, not what I was hoping to read, but I’ll do what I have to.

On a few F150 forums, simply unplugging it had zero consequences, other than disabling the Auto Stop/Start (which was their intent). I’ve also read some models allow BMS to be turned off in FORSCAN, but I haven’t looked yet if that’s available on the FiST.

 

[thecman02]

I'm trying to find you some more concrete information other than just spitballing. If I find anything I'll definitely chime in if you haven't already found the info.

 

[cidsamuth]

So …. because I didn’t want to have another issue to work through later with this motor swap, I put the sensor on the battery and ran the wires back to the engine bay. Thanks for the help.