39.2 kWh Capacity Sets New Benchmark for Home Batteries, Switches Power in 50 Milliseconds During Outages
Austin, Texas-based energy startup Base Power officially launched its new home battery system, Core, on August 3. With a single-unit capacity of 39.2 kilowatt-hours (kWh), Core is the largest home battery currently available on the market. The company states that Core is designed for extreme weather conditions, operating reliably in temperatures ranging from -22°F to 122°F, and features an IP67 waterproof rating, allowing it to withstand submersion in up to three feet of water for 30 minutes without damage.
Core utilizes lithium iron phosphate (LFP) battery technology and can switch a home’s power supply to battery backup in just 50 milliseconds during outages, minimizing disruption to household appliances. Zach Dell, CEO of Base Power, said that Core is engineered to help households maintain normal living conditions during power outages while also functioning as part of a virtual power plant (VPP) to provide grid services when the power network is operational. Users can monitor the battery’s status in real time and receive estimates of remaining backup time through the Base app.
According to data provided by Base Power, Core can support whole-home backup for up to 36 hours under typical household electricity usage. With two units installed, the total capacity increases to 78.4 kWh, extending backup time to up to 72 hours in energy-saving mode. However, actual backup duration varies depending on household electricity consumption, with high-power appliances like air conditioners significantly reducing battery runtime. Core also supports solar charging and can be supplemented with external generators, enhancing flexibility.
Thousands of Units Produced Monthly at Austin Factory; Pre-Orders Open in Texas and Illinois
Core is currently in mass production at Base Power’s Base Factory 1 in Austin, with the company claiming a monthly output of thousands of units. As of August this year, Base Power has deployed over 500 MWh of residential battery capacity across the U.S., a fivefold increase from the 100 MWh deployed by October 2025. The company has also partnered with multiple Texas utilities to launch virtual power plant programs, including El Paso Electric, Austin Energy, and CoServ, with a total dispatch capacity exceeding 200 MW.
In Oncor’s service territory in Texas, Base Power offers Core installation for a fee of $695, along with a $19 monthly membership fee. The company states that revenue generated from grid dispatch services helps subsidize the cost of customers’ backup systems. Core is now available for pre-order in select areas of Texas and Illinois, with plans to expand to additional states and cities in the future.
Raises $1 Billion in Series D Funding, Valuation Reaches $13 Billion
On August 3, Base Power announced the completion of a $1 billion Series D funding round, led by Ribbit, Addition, Valor Equity Partners, and JPMorgan Chase’s Strategic Investment Group. Following this round, the company’s valuation reached $13 billion, with total capital raised exceeding $2.5 billion. Base Power stated that the new funds will be used to expand Core’s deployment across the U.S., hire additional staff, and accelerate market growth.
CEO Zach Dell said that the launch of Core represents a major breakthrough in the home energy storage sector, providing households with reliable backup power while also enhancing grid resilience. He emphasized that Core’s design balances high performance, durability, and affordability, aiming to set a new standard in the home battery market. The company has already collaborated with multiple utilities to advance virtual power plant projects and plans to continue expanding its service offerings.
