How a Car Battery Charges from High-Voltage Stations Using a Capacitor
This patent describes a vehicle power system that uses a capacitor in series with a lower-voltage battery to allow charging from standard electric vehicle charging stations that supply a higher minimum voltage.
Original patent title: “Vehicle power supply system”
This patent describes a vehicle power system that uses a capacitor in series with a lower-voltage battery to allow charging from standard electric vehicle charging stations that supply a higher minimum voltage. Granted to Mazda Motor in 2022 with 23 claims, and it is expected to expire in 2040.
Coverage
What does this patent actually cover?
The patent details a vehicle power supply system designed to charge from an electric vehicle (EV) charging station that provides a voltage at or above a certain minimum, like 50 volts (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 2). The system includes a battery with a rated voltage lower than this minimum, for example, 48 volts (Claim 5). To bridge this voltage gap, a capacitor is connected in series with the battery (Claim 1). The combined rated voltage of the battery and capacitor together is higher than the charging station's minimum voltage. For instance, a 48V battery combined with a 72V capacitor (Claim 4) creates a 120V series, allowing it to interface with a 50V or higher charging station. The system's circuitry then manages the power received from the charging station to charge both the battery and the capacitor (Claim 1). An example of usage would be a mild-hybrid vehicle with a 48V battery system being able to use a public EV fast charger designed for higher voltage full EVs.
The gap
What does this patent NOT cover?
- Does not cover vehicle power systems where the battery's rated voltage is already equal to or greater than the charging station's lower limit voltage (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover systems where the capacitor is not electrically connected in series with the battery during charging (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover systems where the combined rated voltage of the battery and capacitor is less than or equal to the charging station's lower limit voltage (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover systems that only use a battery or only a capacitor for energy storage, without the series combination (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
- Does not cover charging systems that do not receive power from an external EV charging station (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 1).
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The clever bit is using a capacitor in series with a lower-voltage battery to effectively 'boost' the perceived voltage for the charging station, making the combined unit compatible with higher-voltage charging infrastructure without requiring a complex, high-power DC-DC converter for the entire charging path.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
Mild-hybrid vehicles with 48V electrical systems
Vehicles designed to charge from public EV charging stations with non-standard battery voltages
Future Mazda mild-hybrid or plug-in hybrid models
Why it matters
The bigger picture
This patent addresses a challenge for vehicles that use lower voltage battery systems, such as 48V mild-hybrids, which typically cannot directly use public EV charging infrastructure designed for higher voltage full electric vehicles. By enabling these vehicles to interface with standard EV charging stations, it could expand their charging options and convenience. This could be particularly relevant for Mazda, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, as they have explored mild-hybrid technologies.
Filed
January 27, 2020
Granted
June 7, 2022
Market context
Who's building on this
Companies in this space
Mazda Motor Corp, the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is likely exploring this technology for its future vehicle lineup, particularly those incorporating mild-hybrid or plug-in hybrid systems. Other automotive manufacturers developing 48V mild-hybrid architectures, such as Mercedes-Benz, Audi, and BMW, might also find similar solutions relevant for expanding charging compatibility.
Market impact
This patent could potentially broaden the appealappealAfter repeated rejections, an applicant can appeal to the PTAB — and from there to federal court. Slow and expensive.Read more → and practicality of vehicles with lower-voltage battery systems by making them compatible with the growing public EV charging infrastructure. It offers a pathway for mild-hybrid vehicles, which are often seen as a stepping stone to full EVs, to gain more flexible charging options, potentially increasing their market acceptance and reducing range anxiety for their electric-assist capabilities.
Claim 1 — Plain English
What this patent covers
The patent details a vehicle power supply system designed to charge from an electric vehicle (EV) charging station that provides a voltage at or above a certain minimum, like 50 volts (Claim 2). The system includes a battery with a rated voltage lower than this minimum, for example, 48 volts (Claim 5). To bridge this voltage gap, a capacitor is connected in series with the battery (Claim 1). The combined rated voltage of the battery and capacitor together is higher than the charging station's minimum voltage. For instance, a 48V battery combined with a 72V capacitor (Claim 4) creates a 120V series, allowing it to interface with a 50V or higher charging station. The system's circuitry then manages the power received from the charging station to charge both the battery and the capacitor (Claim 1). An example of usage would be a mild-hybrid vehicle with a 48V battery system being able to use a public EV fast charger designed for higher voltage full EVs.
The clever bit
The clever bit is using a capacitor in series with a lower-voltage battery to effectively 'boost' the perceived voltage for the charging station, making the combined unit compatible with higher-voltage charging infrastructure without requiring a complex, high-power DC-DC converter for the entire charging path.
What it does not cover
- Does not cover vehicle power systems where the battery's rated voltage is already equal to or greater than the charging station's lower limit voltage (Claim 1).
- Does not cover systems where the capacitor is not electrically connected in series with the battery during charging (Claim 1).
- Does not cover systems where the combined rated voltage of the battery and capacitor is less than or equal to the charging station's lower limit voltage (Claim 1).
- Does not cover systems that only use a battery or only a capacitor for energy storage, without the series combination (Claim 1).
- Does not cover charging systems that do not receive power from an external EV charging station (Claim 1).
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Early stage
Citation count
0/40
No citations yet
Claim breadth
15/20
Broad claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →
Recency
20/20
Granted within 5 years
Assignee scale
0/20
Independent or smaller assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$21K – $67K
Midpoint $42K · 13.3 yr remaining · industry ×0.9
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
23 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Hirano, S., SANAI, H., & Furukawa, A. (2022). How a Car Battery Charges from High-Voltage Stations Using a Capacitor (U.S. Patent No. 11,351,876). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/11351876/vehicle-power-supply-system
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
Embed
Add this patent to your site
Drop this plain-English patent card into any blog post or article — free, no signup. It always links back to the full breakdown here.
<div data-patentlens-widget data-patent-number="US11351876"></div> <script src="https://patentbrief.org/embed.js" async></script>
Stay in the loop
Get a weekly digest of new patents.
One email per week. No spam. Unsubscribe anytime.
Keep exploring
Related patents you should know
US 4683195 · 1987
How to Make Billions of Copies of a DNA Segment
This patent describes the Polymerase Chain Reaction (PCR), a method to rapidly create many copies of a specific piece of DNA or RNA, enabling its detection and analysis.
Cetus Corp
US 8697359 · 2014
How to Edit Genes in Human Cells Using an Engineered CRISPR System
This patent describes an engineered CRISPR-Cas9 system for precisely cutting DNA in eukaryotic cells to change how genes work, opening the door for gene editing in complex organisms.
Massachusetts Institute of Technology
US 7657849 · 2010
How the iPhone's Slide-to-Unlock Gesture Works
Apple's 2010 patent describes unlocking a device by dragging a specific graphical image across the touchscreen along a predefined path, a gesture that became iconic with the original iPhone.
Apple Inc
US 4733665 · 1988
How Doctors Implant a Permanent Stent Using a Balloon
This patent describes the method for placing a permanent, expandable wire mesh tube inside a blood vessel or other body tube using a balloon-tipped catheter to widen it and keep it open.
Expandable Grafts Partnership
US 4965188 · 1990
How to Make Many Copies of a DNA Piece with Heat
This patent describes the Polymerase Chain Reaction (PCR) method, a technique to make millions of copies of a specific DNA segment using a heat-resistant enzyme and repeated temperature changes.
Cetus Corp
US 4235871 · 1980
How to Encapsulate Active Materials in Lipid Bubbles Efficiently
This patent describes a method for trapping biologically active substances inside tiny, multi-layered fat bubbles called liposomes, using a specific water-in-oil emulsion and gel-forming process to improve how much material gets captured.
Individual
Semantically similar
You might also find these interesting
US 20180339601
High-Power Electric Vehicle Charging with Pulsed Current from the Grid
US 20120091953 · Tesla Motor
How Electric Cars Adjust Charging Speed to Available Power
US 10967755 · 2021 · Zincfive Power
Smart Charging for Nickel-Zinc Batteries in Hybrid Power Systems
US 9168838 · 2015 · NEC
How an EV Charging Station Manages Power from Batteries and the Grid
More to explore
More in Energy & Clean Tech
US RE49155 · 2022 · Halliburton Energy Services Inc
Electric or Natural Gas Blending and Pumping for Oil Wells
US 11436484 · 2022 · Nvidia Corp
Nvidia's Method for Training Self-Driving Car AI in Simulations
US 11840398 · 2023 · Titan Trailers Inc
How Titan Trailers Builds Stronger, Smoother Cargo Containers
US 2708656 · 1955
How the First Nuclear Reactor Works
New to patents?
Common Questions
Frequently Asked Questions
What does How a Car Battery Charges from High-Voltage Stations Using a Capacitor cover?
This patent describes a vehicle power system that uses a capacitor in series with a lower-voltage battery to allow charging from standard electric vehicle charging stations that supply a higher minimum voltage.
Who owns patent US 11351876?
Mazda Motor owns this patent, granted in 2022.
When does this patent expire?
This patent is expected to expire on January 27, 2040, when the invention enters the public domain.
What problem does this patent solve?
This patent addresses a challenge for vehicles that use lower voltage battery systems, such as 48V mild-hybrids, which typically cannot directly use public EV charging infrastructure designed for higher voltage full electric vehicles. By enabling these vehicles to interface with standard EV charging stations, it could expand their charging options and convenience. This could be particularly relevant for Mazda, the assignee, as they have explored mild-hybrid technologies.
What does this patent NOT cover?
Does not cover vehicle power systems where the battery's rated voltage is already equal to or greater than the charging station's lower limit voltage (Claim 1).
Patent monitoring