As per Mopar:
How Does Ram 1500's eTorque Mild Hybrid Technology Work?
A 48-volt battery pack works with the motor generator to create:
- a seamless start/stop function;
- a short-duration torque addition to the engine crankshaft in particular driving conditions; and,
- brake energy regeneration to increase efficiency and responsiveness.
With the engine is running and the truck ready, Ram eTorque's motor generator unit delivers 48-volt current to a 430 watt-hour lithium-ion Nickel Manganese Cobalt (NMC)-Graphite battery. The battery pack on these Ram pickups includes a 3-kilowatt DC-to-DC converter. This holds the battery's charge and converts 48 volts to 12 volts so that power can be use to power Ram 1500's accessories and charge its conventional 12-volt lead-acid battery.
About the size of a small suitcase, the air-cooled battery plant is mounted to the interior rear wall of Ram 1500's cabin. The battery pack's case is insulated to hush the noise generate by the dual cooling fans. Cooling air is then drawn from the truck interior and released through the built-in cabin exhausters.
Because of its greater efficiency in extreme temperatures, both the V6 engine and V8 engine with Ram eTorque technology will keep a traditional 12-volt starter motor, which is ideal for cold starts and the initial start of the day.
Beyond spinning the engine for restarts, the eTorque also recaptures energy during deceleration and braking to recharge the battery pack. Further, Ram eTorque also bolsters the driving experience of the 2019 and 2020 Ram 1500 with additional torque to the crankshaft during gear changes, which minimizes noise, vibration, and harshness (NVH).
There is a slight variation in the Ram eTorque motor generator between the 3.6-liter Pentastar V-6 and the 5.7-liter HEMI V-8 applications to optimize performance in both powertrains. The Pentastar sports a liquid-cooled Ram eTorque unit mounted on the front of the engine. The HEMI V-8 features an air-cooled Ram eTorque unit that is mounted toward the top of the engine where a traditional alternator would be located.