> ## Content Index
> Fetch the complete content index at: https://genius-energy.ghost.io/llms.txt
> Use this file to discover other available public pages before exploring further.

# The Home Battery That Skips Lithium Entirely
- URL: https://genius-energy.ghost.io/the-home-battery-that-skips-lithium-entirely/
- Published: 2026-09-02T09:39:47.000Z
- Updated: 2026-09-02T09:39:47.000Z
- Author: Mason Vance

A San Diego company has begun installing home storage systems in European houses that contain no lithium at all. The chemistry is sodium-ion, the product is called Na+Casa, and each module holds 9.25 kWh of usable energy in a wall-mounted cabinet. Unigrid says a US launch follows by the end of 2026.  

### What Swapping the Ion Actually Changes

Sodium-ion cells work on the same principle as the lithium batteries already hanging in a few million garages. Ions travel from one electrode to the other when the pack charges and travel back when it discharges. The only thing that changes is which ion does the traveling.

Sodium is heavier and physically larger than lithium, so a sodium cell stores less energy per pound. It is also cheap, abundant, and it tolerates temperature far better at the edges.

That last part is where the spec sheet gets interesting. The Na+Casa is rated to discharge from -40F up to 140F and to charge from -4F. Most lithium home batteries simply refuse to charge below freezing until an internal heater warms the cells, and that heater runs on energy from the pack. In an unconditioned garage in January, the difference is not academic.

The tradeoff is mass and volume. One 9.25 kWh module weighs roughly 240 pounds and stands about 34 inches tall. A lithium iron phosphate unit of similar capacity is lighter and slimmer. If the only viable install location is a narrow utility closet, that is a real constraint.

Lifespan is the other headline. Unigrid rates the pack at 10,000 full cycles and markets a 25-year service life. Most lithium home batteries carry a 10-year warranty. A 25-year claim has obviously not been proven by 25 years of field data, and the company still lists UL 9540 and UL 1973 as pending rather than complete. Those are the certifications that utilities and local inspectors typically want to see before approving an interconnection, so the US timeline depends on paperwork as much as on manufacturing.

**The Hardware Stack:**

**Unigrid Na+Casa:** The first-generation residential sodium-ion system, shipping in Europe now, with US availability targeted for late 2026.

**CATL Naxtra:** The sodium-ion cell line from the world's largest battery maker, which reached mass production this year and is what makes cheap sodium cells plausible at scale.

**Tesla Powerwall 3:** The lithium iron phosphate benchmark most homeowners compare against, with a 10-year warranty and an integrated solar inverter.

### Vulnerability Score

**No stored energy:** A home without storage is fully dependent on utility supply. When the line goes down, everything on the panel goes with it, including the well pump, the furnace fan, and the refrigerator.

**Cold-weather charge limits:** Storage that cannot accept a charge below freezing recovers slowly during a winter outage, which is exactly when outages are longest and solar production is weakest.

**Single-chemistry supply:** Home storage today rests almost entirely on lithium. A second workable chemistry reduces the odds that a supply squeeze or a price spike stalls installations.

### Where This Sits Right Now

Sodium-ion is not going to replace lithium in home storage this year. The energy density gap is real, the certifications are not finished, and pricing for US buyers has not been published. What it does is add a second option with a genuinely different temperature profile and a much longer cycle rating.

If you are quoting a system this fall, lithium iron phosphate is still the practical answer. If you are in a cold climate, have space for a larger cabinet, and are not in a hurry, sodium-ion is worth asking your installer about in a year. The useful move now is to note which chemistry a quote actually contains, because for the first time in home storage, that question has more than one answer.

![](https://storage.ghost.io/c/e6/ee/e6ee1e2b-d1a5-4bf5-9ea4-466c4fb0764d/content/images/2026/09/sodiumbattery-closeup.jpg)

---

*Written by Mason Vance*