Battery and Cables
WARNING: This page is about a different car, the 2015 Ford F-150. However, it is still accessible from the selected car via links, so may be relevant.
Vehicles are equipped with a 12-volt, maintenance-free battery. The battery is a 12V DC source connected in a negative ground system and is a voltage stabilizer for the 12V electrical system.
The 2.7L EcoBoost engine is equipped with a battery monitor sensor attached to the negative battery cable. Refer to: Charging System - 2.7L EcoBoost (238kW/324PS) - System Operation and Component Description .
All other engines are equipped with a battery current sensor attached to the negative battery cable. Refer to: Charging System - 3.5L Duratec (209kW/284PS)/3.5L EcoBoost (272kW/370PS)/5.0L 32V Ti-VCT - System Operation and Component Description .
A generator current sensor is attached to the positive battery cable: