Under the skin: The tech making EV batteries smaller and cheaper

Under the skin: The tech making EV batteries smaller and cheaper

Under the skin: The tech making EV batteries smaller and cheaper

Sometimes, the most straightforward ideas are right in front of us, ready to enhance the already relatively simple engineering of electric vehicles (EVs).

Compared to internal combustion engine (ICE) vehicles, EVs are simpler because they eliminate the complexity of fueling and exhaust systems, as well as the intricate emission-treatment paraphernalia.

However, EVs are still considered relatively complex due to the advanced science and electronics that power them. Stellantis, in collaboration with battery manufacturer Saft, has recently introduced the Intelligent Battery Integrated System (Ibis) to further simplify EV components using an innovative approach to battery technology.

EV powertrains consist of several basic elements. The battery, which stores and charges direct current (DC) electricity, powers the electric motors. These motors require alternating current (AC) like a regular household supply, so they are equipped with inverters to convert between AC and DC power.

Additionally, an on-board charger converts AC current from the grid into DC power to charge the battery.

EV batteries, more correctly referred to as battery packs, consist of numerous small, low-voltage lithium-ion cells. These cells are grouped into modules within the pack. Consequently, while a battery pack might generate 400V or 800V, each individual module can have as low as 11V depending on the pack’s size and design.

The Ibis project takes inspiration from photovoltaic systems to reduce EV hardware. Solar power systems use multiple solar panels that produce DC electricity, which is then fed to a single inverter to convert it into AC power. Alternatively, microinverters can be used to convert DC power to AC power as it leaves each individual panel.

The Ibis project adopts a similar approach. Each battery module includes a microinverter and a charger, eliminating the need for a separate on-board charger and a high-voltage inverter(s) for multiple drive motors.

By the end, the complete battery pack produces AC power to directly supply the motor, instead of DC power. Stellantis believes that this approach will benefit smaller EVs where space is a premium. Furthermore, this approach may be more cost-effective, as multiple smaller charger and inverter electronics are likely cheaper than their high-voltage counterparts that they replace.

While the Ibis project demonstrates innovative thinking to enhance EVs, it may not be compatible with other concepts like Volkswagen’s aim to integrate individual cells directly into the car’s chassis (“Cell2Car”).