How Battery Energy Storage Systems (BESS) Support EV Fast Charging

Electric vehicles (EVs) are no longer just a trend—they're the future of transportation. But with more EVs on the road, there's growing pressure on the energy grid, especially as demand rises for fast charging. Charging a single vehicle at 150kW or more in under 30 minutes draws a massive amount of electricity, which many existing grids weren’t built to handle.

That’s where Battery Energy Storage Systems (BESS) come in. These systems store electricity during off-peak hours or when renewable energy is plentiful, then release it during high-demand periods—making EV charging more stable, efficient, and sustainable.

In this article, we’ll explore how energy storage for EV charging addresses grid limitations, lowers operating costs, and powers the next generation of charging networks.

The Core Challenges of EV Fast Charging

EV fast chargers are powerful tools—but they come with serious infrastructure challenges:

• High Instant Power Demand: Fast chargers (150kW to 350kW) draw large amounts of electricity in short bursts. Multiply that by multiple cars charging at once, and the local grid can quickly become overwhelmed.
• High Electricity Costs: Utility companies often charge commercial users based on their peak demand, meaning the highest amount of energy drawn at any one time. Fast charging can cause spikes that lead to expensive electricity bills.
• Limited Grid Capacity: Many locations, especially remote areas or city centers, don’t have the grid strength or infrastructure to support fast charging without costly upgrades.
• Renewable Integration Gaps: Solar and wind energy are clean and abundant—but not always available when needed. Without storage, much of this energy goes to waste.

How Battery Energy Storage Systems (BESS) Support EV Charging

BESS bridges the gap between what EV charging stations demand and what the grid can supply. Here’s how:

1. Managing Peak Demand

Electricity is usually cheaper late at night and more expensive during the day. BESS takes advantage of this by storing energy when prices are low (for example, between 11pm and 7am) and discharging it during peak times (like 4pm to 8pm), when rates are highest.

In one real-world case, Blink Charging reported off-peak electricity prices of $0.1749/kWh compared to peak prices of $0.1927/kWh during heat waves. For a station using 6,000 kWh per month, BESS can save hundreds of dollars—every month.

This is known as “peak shaving”, and it helps charging station operators avoid costly demand charges while keeping operations smooth and predictable.

2. Power Buffering for Fast Chargers

Fast chargers can deliver large bursts of power to EVs—but the local grid often can't keep up with these demands. BESS acts as a power buffer, providing high-output electricity instantly when needed.

For example, Connected Energy’s E-STOR system can support 20 EVs charging at 7kW for up to 2.5 hours, using stored energy without requiring a grid upgrade. This setup is especially useful in locations with limited grid access, like highway service stations or urban neighborhoods.

By supplying stored power when demand spikes, BESS protects the grid from overload and helps ensure stable charging performance.

3. Supporting the Grid in Constrained Areas

Many promising EV charging locations—rural highways, fleet depots, busy urban zones—don’t have the grid capacity to support high-speed charging. Installing a new substation or upgrading infrastructure can take years and cost millions.

BESS allows these stations to operate independently or semi-independently, even in grid-constrained environments. In Germany and Belgium, Allego uses BESS to support fast-charging stations along motorways. The storage systems respond in real-time using open charge protocols, making smart energy use possible without massive infrastructure investments.

4. Enabling Clean, Renewable EV Charging

One of the most exciting uses of BESS is its ability to store solar or wind power for EV charging. This allows operators to offer zero-emissions energy, even when the sun isn't shining.

For instance, in Dundee, Scotland, the local government uses solar panels paired with BESS to provide clean energy to its public charging network. The system monitors energy use and weather patterns, ensuring that every kilowatt-hour from the sun gets used effectively—even at night.

This integration of renewable energy + storage + EV charging is a critical step toward achieving net-zero carbon goals.

Energy Storage for EV Charging: Real-World Success Stories

The impact of BESS on EV charging isn’t just theory—real-world examples show major benefits:

Brazil's E-Lounge Project: After adding BESS to its 60kW DC fast chargers, energy use jumped from 0.6 MWh to 10.36 MWh/month, a 21-fold increase. The system improved energy quality and reduced peak load stress.

Nottingham City Council (UK): Their depot includes two E-STOR units and solar arrays. The BESS smooths charging loads, supports bi-directional charging, and maximizes solar energy use.

Blink Charging (Philadelphia): Their first U.S. site with BESS powers four DC fast chargers. It's fully operational even during outages, helping expand charging access without overloading the grid.

These projects highlight how energy storage for EV charging is not just efficient—but essential.

Conclusion: Future-Ready EV Charging Starts with Energy Storage

As EV adoption grows, the need for fast, reliable, and clean charging becomes critical. Battery Energy Storage Systems offer a flexible, cost-effective solution to the key challenges of fast charging:

• They reduce peak demand and electricity costs
• They make fast charging possible even where the grid is weak
• They enable green energy use and improve system reliability

The message is clear: If you're planning to scale your EV charging infrastructure, energy storage should be part of the foundation.

Power Your Fast Charging Future with ACE Battery

At ACE Battery, we develop smart and scalable energy storage solutions for EV charging. Whether you're building a public charging network, upgrading your commercial fleet infrastructure, or exploring solar-powered EV stations, our BESS systems are designed to deliver reliable performance—anywhere, anytime.

Contact us to explore ACE Energy Storage for EV charging and learn how ACE Battery can help you future-proof your EV charging operations with clean, intelligent energy storage.