Hey all, 

So my wife's 2012 Ford Focus 1.0 EcoBoost with low miles have been running great for 5 years straight. Not a single issue. Serviced and looked after. Yesterday she came home from work, no problems, and parked on the driveway. 15 minutes later we were heading out again and the car cranked about 1 turn and then clicked. Tried a few times until it eventually just clicked when cranking. It has the push button start. 

So I went straight for battery and had a look. The battery indicator is green, but that can't always be trusted, so I hooked up my booster to it. No difference. Also tried starting it from a battery that I know is good. No difference. 

Here's when the interesting part comes.. The windows won't go up and down anymore, they all just click. The wipers are twitching. The infotainment system acts out. And more weird electrical issues. Everything has been working perfect before. No warning or check engine lights. 

I've cleaned the ground point. Any ideas? 

The voltage from the battery is extremely low, so even the booster won't start it.

The other battery you tried was also not good enough to power the car.

First port of call would be a new battery, sounds like you have a dead cell

Failing that, you have water damage in the BCM and it's that that's gone down