Secondary Battery

Overview

Secondary batteries are the backbone of modern electric mobility, enabling vehicles to store and reuse electrical energy efficiently. Unlike primary batteries, which are disposable after a single use, secondary batteries are designed for multiple charge-discharge cycles, making them far more sustainable and cost-effective.

In the EV industry, lithium-ion secondary batteries dominate due to their high energy density, lightweight construction, and long cycle life. These batteries not only extend driving range but also support fast charging, regenerative braking, and intelligent battery management systems (BMS). Their role in advancing electric vehicles highlights their importance in the transition from fossil-fuel-based transport to sustainable mobility solutions.

How Does It Work?

Secondary batteries function through electrochemical reactions that are reversible:

1. Charging Process – Electrical energy from the grid or a charger is converted into chemical energy and stored in the battery’s electrodes.

2. Discharging Process – Stored chemical energy is converted back into electrical energy to power the EV motor and onboard electronics.

3. Regenerative Braking – EVs recover kinetic energy during braking, feeding it back into the battery to extend driving range.

4. Battery Management System (BMS) – Controls charge levels, voltage, and temperature to maximize safety, efficiency, and battery life.

This cyclic operation makes secondary batteries the lifeblood of EV propulsion systems.

Features of Secondary Battery

• Rechargeability – Designed for repeated charge and discharge cycles.

• High Energy Density – Stores significant energy relative to weight and volume.

• Long Cycle Life – Provides thousands of cycles before performance degradation.

• Compatibility with Renewable Energy – Works seamlessly with solar, wind, and smart charging grids.

• Scalability – Can be configured into modules and packs for various EV sizes.

Applications in EV

Secondary batteries power virtually all aspects of electric mobility:

• EV Drivetrains – Supply consistent power for acceleration, cruising, and regenerative braking.

• Plug-in Hybrid EVs (PHEVs) – Work alongside internal combustion engines to reduce fuel usage.

• Fleet Electrification – Enable buses, trucks, and delivery vans to operate on zero-emission energy.

• Energy Storage Integration – Support vehicle-to-grid (V2G) and home energy storage applications.

• Emerging Technologies – Advanced chemistries like solid-state secondary batteries promise faster charging, higher safety, and greater efficiency.

Examples include Tesla’s lithium-ion packs, BYD’s Blade Battery, and Nissan Leaf’s regenerative braking system—all powered by secondary battery technology.

Conclusion

The secondary battery is the heart of every electric vehicle, transforming how energy is stored, delivered, and managed. By combining rechargeability, efficiency, and adaptability, it ensures EVs remain practical, sustainable, and future-ready. As new battery chemistries evolve, secondary batteries will continue to drive advancements in range, safety, and clean energy integration, solidifying their role in the global transition to electric mobility.