Body And Components Of 48 V On-Board Electrical System - SN00.00-P-0070-14S
Model all (CAR)
Structure
On-board electrical system integration is centered on the 48 V powerpack (A) from Mercedes-Benz. It is the size of a conventional 12 V battery but weighs around 5 kg.
The lower part of the powerpack is the 48 V battery (2). It consists of 12 lithium-ion cells connected in series with a peak output of 16 kW and has a capacity of 20 Ah. The battery has its own control electronics including battery management system (BMS).
The bidirectional DC/DC converter (1) for variable coupling of the 12 V and 48 V side is integrated on the top side of the powerpack. The DC/DC converter can either supply the 12 V on-board electrical system with 3 kW of continuous output or charge the 48 V on-board electrical system with up to 1 kW of output from the 12 V on-board electrical system.
The DC/DC converter also forms the signal interface between the energy management of the drivetrain, the energy management of the overall vehicle and the large and powerful 48 V battery.
In addition, a heat sink with a water connection (3) and a thermal rapid cooling and heating element have been integrated into the 48 V powerpack. When the battery is cold, the cooling and heating element acts as a battery heater, and when the battery is hot, it improves the cooling performance and thereby guarantees optimized and energy-efficient performance of the 48 V on-board electrical system even in extreme temperatures.
There are variants of the powerpack in use with which no distinction is made between the 48 V battery and the DC/DC converter. In these cases, the powerpack is passively cooled and if replacement is necessary, the entire powerpack is replaced.
Shown: 48 V on-board electrical system, shown on model 223 with engine 256
Shown: 48 V on-board electrical system, shown on model 206
Components in the 48 V on-board electrical system
The 48 V E-ACTIVE BODY CONTROL (eABC) suspension is used as an option in the STAR3 model series. This type of active suspension cannot realistically be implemented with existing 12 V technology due to the necessary power and high currents.
The 48 V suspension consumes valuable electrical energy only for dynamic interventions to compensate for pitching, rolling and tilting. During body countermovements, it feeds charge back into the 48 V powerpack.
Consequently, energy recuperation has been implemented not only during braking and coasting but also in the suspension itself.
Also new, for example, are two fast and powerful electric 48 V heaters, which provide a more pleasant climate in the vehicle interior in cold weather. Switching the heater over from 12 V to 48 V not only offers more comfort but also reduces energy transmission loss due to lower current at identical output.