# XL Batteries funding: rounds and investors

> XL Batteries has raised $21M across 2 rounds since 2025. Investors include National Science Foundation and Third Derivative. Every round with its source.

Source: https://millionrounds.com/company/xl-batteries (Millionrounds; every figure on the page links to its filing or article)

United States · [Venture startup](https://millionrounds.com/companies)

# Who invested in *XL Batteries*

2 rounds we have observed, with the 2 investors named in them. Every figure came from a named source, and where the company reported a raise to the SEC itself, that is shown beside it.

Energy

Raised 4 months ago

Funding summary Updated 26 Oct 2026

**$21M** raised across 2 rounds since 2025, from 2 sources

**$7.5M** Seed **$13M** Venture

- **Latest round:** Venture, $13M Jul 2026
- **Step-up i:** 1.7×
- **Investors:** 2

See who backed them

## The funding story

Each circle is a round, placed by date and sized by amount. The line above is the running total.

2026

**$7.5M** Seed

**$13M** Venture

- **First round:** Seed, $7.5M
- **Biggest round:** $13M
- **Between rounds:** 10 months

## The rounds

- **Jul 2026** Venture **$13M** *2 returning* [National Science Foundation](https://millionrounds.com/fund/nsf-small-business-innovation-research-small-business-techno) [Third Derivative](https://millionrounds.com/fund/third-derivative) Source recorded SEC filing: $13M sold
- **Sept 2025** Seed **$7.5M** *2 new* [National Science Foundation](https://millionrounds.com/fund/nsf-small-business-innovation-research-small-business-techno) [Third Derivative](https://millionrounds.com/fund/third-derivative) Source recorded SEC filing: $7.5M sold, first sale Aug 2025

## Founders and team

From XL Batteries's own website: 2 on the team.

- **Tom Sisto** CEO
- **Mike Rubino** CFO

## Who was in which round

The busiest backers across the latest rounds. A filled square is a round they joined; a dark one, a round they led.

**Seed** 2025 **Venture** 2026 [National Science Foundation](https://millionrounds.com/fund/nsf-small-business-innovation-research-small-business-techno) [Third Derivative](https://millionrounds.com/fund/third-derivative)

## Everyone who backed them

[National Science Foundation](https://millionrounds.com/fund/nsf-small-business-innovation-research-small-business-techno) Government **2** rounds

[Third Derivative](https://millionrounds.com/fund/third-derivative) Accelerator **2** rounds

Missing a round, or an investor who was in one? [Tell us](https://millionrounds.com/corrections?slug=xl-batteries).

## Also claim to have backed them

This firm lists XL Batteries as a portfolio company on their own website, but no report of a round names it. They are the firms' own claims, kept apart from the rounds above.

[SIP Global Partners](https://millionrounds.com/fund/sip-global-partners) VC firm Per its own site

## Quick answers about XL Batteries

### Who invested in XL Batteries?

XL Batteries's investors include National Science Foundation and Third Derivative.

### How much has XL Batteries raised?

XL Batteries has raised $21M across 2 rounds since 2025.

### When did XL Batteries last raise?

XL Batteries's most recent round was a Venture of $13M in Jul 2026.

### What was XL Batteries's biggest round?

Its most recent round, $13M in Jul 2026, is also its largest on record.

### Who backed XL Batteries first?

XL Batteries's first round on record, in Sept 2025, was backed by National Science Foundation and Third Derivative.

### What stage is XL Batteries at?

XL Batteries's latest named round is a Venture, in Jul 2026.

### Where is XL Batteries based?

XL Batteries is based in the United States.

## Companies like XL Batteries

In the same sector, and raised in the last eighteen months.

[**Amogy** $125M · Oct 2026](https://millionrounds.com/company/amogy)[**LanzaJet** $67M · Oct 2026](https://millionrounds.com/company/lanzajet)[**Pivot Energy** $500M · Oct 2026](https://millionrounds.com/company/pivot-energy)[**Peak Energy** $163M · Oct 2026](https://millionrounds.com/company/peak-energy)[**Pennsylvania American Water** $43M · Oct 2026](https://millionrounds.com/company/pennsylvania-american-water)[**Vertical Semiconductor** $84M · Oct 2026](https://millionrounds.com/company/vertical-semiconductor)

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