# How an EV Charging Station Manages Power from Batteries and the Grid > This patent describes a smart charging system for electric vehicles that decides whether to power cars from a local battery or the main electricity grid, and when to recharge that local battery, to help balance power demand. - **Patent:** US 9168838 - **Original title:** Charging control system and charging control method - **Owner:** NEC - **Granted:** 2015 - **Status:** Active - **Times cited:** 1 - **Field:** telecommunications, energy, automotive, software, consumer_electronics ## What it does This patent describes a system that intelligently controls how electric vehicles (EVs) are charged. It uses a "stationary rechargeable means" (like a large battery bank) alongside the main "electric power grid" to supply power. A "charging control means" decides the power source: if EV charging meets a "predetermined condition" (e.g., needing power quickly during peak grid demand), the EV gets electricity from the stationary battery. Otherwise, the EV charges directly from the grid. Simultaneously, the stationary battery itself is recharged from the grid, especially during times when fewer vehicles are charging, as determined by a "charging scheduling means." For example, a a charging station might charge EVs from its local battery during a busy afternoon, then recharge the local battery from the grid overnight when electricity is cheaper and demand is low. ## What it does NOT cover - Does not cover charging systems that only draw power directly from the electric grid without using an intermediate stationary battery. - Does not cover systems that charge electric vehicles exclusively from a stationary battery without any connection to a larger electric power grid. - Does not cover systems where the decision to charge from the stationary battery or grid is not based on a "predetermined condition" for the vehicle's charging. - Does not cover charging scheduling that doesn't consider both vehicle charging and stationary battery charging as part of the overall electric power demand. - Does not cover systems that don't specifically shift stationary battery charging to times with fewer vehicles being charged. ## The clever bit The clever part is the dynamic decision-making for both the EV's power source and the stationary battery's recharge schedule, specifically using low-demand periods to replenish the stationary battery while using it to offload the grid during high-demand times. This optimizes grid usage and potentially reduces costs. ## Real-world examples 1. EV charging stations with integrated battery storage 2. Fleet charging depots for electric buses or delivery vans 3. Smart grid energy management systems ## Why it matters This patent addresses the challenge of managing electricity demand when many electric vehicles need charging. By using a stationary energy storage, it helps smooth out peak loads on the electric grid, making EV charging more efficient and potentially cheaper. This approach is important for the development of large-scale EV charging hubs and smart grids. ## Frequently asked questions ### What does How an EV Charging Station Manages Power from Batteries and the Grid cover? This patent describes a smart charging system for electric vehicles that decides whether to power cars from a local battery or the main electricity grid, and when to recharge that local battery, to help balance power demand. ### Who owns patent US 9168838? NEC owns this patent, granted in 2015. ### When does this patent expire? This patent is expected to expire on February 29, 2032, when the invention enters the public domain. ### What is patent US 9168838 cited by? This patent has been cited by 1 later patents that build on its ideas. ### What problem does this patent solve? This patent addresses the challenge of managing electricity demand when many electric vehicles need charging. By using a stationary energy storage, it helps smooth out peak loads on the electric grid, making EV charging more efficient and potentially cheaper. This approach is important for the development of large-scale EV charging hubs and smart grids. ### What does this patent NOT cover? Does not cover charging systems that only draw power directly from the electric grid without using an intermediate stationary battery. **Full plain-English explainer:** https://patentbrief.org/patent/us/9168838/charging-control-system-and-charging-control-method **Original patent:** https://patents.google.com/patent/US9168838 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [Smart EV Charging to Protect Battery Life During Long Parking](https://patentbrief.org/patent/us/11235681/curtailing-battery-degradation-of-an-electric-vehicle-during-long-term-parking) — This patent describes a system that intelligently discharges and recharges an electric vehicle's battery while parked for a long time, like at an airport, to prevent battery damage and ensure it's ready when the owner returns, using vehicle-to-grid technology. - [How Electric Cars Safely Pause Charging When You Want to Unplug](https://patentbrief.org/patent/us/9379564/charging-control-apparatus-and-charging-control-method) — A system for electric vehicles that safely pauses power flow when a driver signals they want to disconnect the charging cable, preventing electrical arcing or damage. - [Device That Adjusts Power for Charging Multiple Devices](https://patentbrief.org/patent/us/9368994/dynamic-charging-device-and-method-thereof) — This 2016 patent describes a system that intelligently adjusts the power supplied to charge multiple devices, ensuring one device gets a steady charge while another can receive a variable amount. - [How to Grade Used Batteries for a Second Life](https://patentbrief.org/patent/us/9397374/secondary-battery-module-battery-information-management-device-battery-informati) — This patent describes a system that reads electrical characteristics and usage history from a rechargeable battery module to determine if it's good enough to be used again for a different purpose, like energy storage. - [How to Fast-Charge Lithium Batteries Without Damaging Them](https://patentbrief.org/patent/us/10700376/methods-for-fast-charging-and-detecting-lithium-plating-in-lithium-ion-batteries) — This patent describes a three-phase method for quickly charging lithium-ion batteries while carefully controlling voltages to prevent harmful lithium metal buildup and electrolyte damage.