Bosch has introduced a new 48-volt battery for mild hybrids; similar to the Bosch e-axle, this 48-volt battery is standardized for easy integration into new vehicle models. Established manufacturers and start-ups alike can thus eliminate long and expensive development processes. Bosch intends for this pack—along with its earlier work on mild hybrid systems (earlier post)—to position it as a leader in the burgeoning 48V mild-hybrid market.
The pack configuration is 12s1p with 8Ah, NMC/Graphite cells. Charge power is 13 kW, discharge power is 11 kW. Package weight is less than 7kg. Production of the battery is scheduled to start in late 2018.
Anticipating a large market for entry-level hybrids, Bosch offers other powertrain components for these models in addition to the 48-volt battery. The company estimates that some 15 million 48-volt hybrid vehicles will be on the road by 2025.
Bosch said that it is already in talks with over a dozen customers for the 48V battery and has secured a considerable number of production projects.
The battery offers a comparatively inexpensive way to help reduce vehicle CO2 emissions. This is also due to the product design, as the battery requires no active cooling and its housing is made of plastic, not metal. Both these factors bring costs down still further.
|Bosch opted for an NMC:C chemistry for the 48V pack. Source: Bosch. Click to enlarge.|
The plastic housing presents a real challenge, as lithium-ion cells expand when the battery is charging and over the course of the unit’s service life. As a result, the housing must withstand a certain amount of stress. Bosch engineers rearranged the cells in the 48-volt battery so that even plastic housing can bear the pressure.
We are demonstrating that there is more to a battery than making it perform faster, stronger, farther; instead, there is an art to finding a suitable user-friendly solution. We are confident that this will position us as a market leader for 48-volt batteries.—Michael Budde, head of Bosch Battery Systems