Stationary storage · Heiwit

Sodium-ion
batteries.

Tomorrow's energy, already in your system.

Batterie da 10 kWh a 48 V, da abbinare agli inverter ibridi Heiwit. Un sistema che cresce con le tue esigenze, fino a 30 kWh.

Discover the range Request information

10 kWh: Capacità per batteria
48 V: Tensione della batteria
30 kWh: Fino a 3 batterie in parallelo
10 years: Warranty

01 / The range

One system.
Multiple configurations.

La batteria da 10 kWh lavora con gli inverter ibridi Heiwit VIRGO e LYBRA. È possibile collegare fino a 3 batterie in parallelo per inverter, per una capacità totale di 30 kWh.

Heiwit battery, three-quarter view with side connection panel

Batteria Heiwit

10 kWh sodium-ion battery

48 V and integrated BMS, to manage residential and commercial energy storage. The cells contain neither lithium nor cobalt.

Explore the product

Batteries in parallel

Capacity follows the needs of the system.

Parti da una batteria da 10 kWh e dimensiona l’accumulo con il tuo installatore. Puoi collegare fino a 3 batterie in parallelo, per un totale di 30 kWh.

10 kWh1 batteria

20 kWh2 batterie

30 kWh3 batterie

Richiedi la tua configurazione

Single-phase hybrid

Virgo

3K-S · 4K6-S · 6K-S

Discover VIRGO

3–6 kW

Three-phase hybrid

Lybra

6K-T · 10K-T · 12K-T

Discover LYBRA

6–12 kW

The battery is designed for direct connection to Heiwit VIRGO and LYBRA inverters. On an existing system, the Heiwit inverter can be connected to the AC line while keeping the PV inverter already installed. Learn more about compatibility.

02 / Specifications and performance

The data at a glance.

Le caratteristiche della batteria e i risultati di prova aiutano a valutare la configurazione più adatta all’impianto.

Capacità della batteria: 10 kWh
Voltage: 48 V
Scalability: Fino a 3 batterie in parallelo / 30 kWh
Battery management: Integrated BMS
Discharge temperature: From −25 to +60 °C
Charge temperature: From 0 to +60 °C
Measured self-discharge: 0.35% per month*
Warranty: 10 years
Compatible inverters: Heiwit VIRGO and LYBRA
Remote monitoring: Heiwit app

*Measured on several batteries, at room temperature, at the latitude of Milan.

2025–2026 version · layered oxide cells

Over 6,500 cycles

Durata stimata di carica e scarica. Nel test a 6.500 cicli, la capacità residua è rimasta superiore al 70%.

Service life depends on depth of discharge, temperature, current and average state of charge: cycles do not automatically equate to years of service.

Cella polianionica · prova di qualifica

Over 90% at −20 °C

Capacity retained by the polyanionic cell in cold tests. The result refers to the cell and test protocol described in the in-depth article.

Read the cold tests

Open the datasheet

03 / The technology

Sodium, for energy
that lasts.

In stationary storage, what matters is service life, safety, thermal behaviour and the cost of the energy exchanged over the entire life of the system.

Materials and recovery

Sodium is an abundant resource. Heiwit cells contain neither lithium nor cobalt; the battery is designed to facilitate the recovery and recycling of materials at end of life.

Layered oxides

Ions move between oxide layers. This is the chemistry of the 2025–2026 version, with a good balance between energy per unit mass and performance.

NFPP polyanionics

Sodium iron phosphate-pyrophosphate forms a rigid three-dimensional lattice. This evolution of the chemistry prioritises stability and behaviour at extreme temperatures.

Learn more about NFPP

Charging cathode → anodeDischarging anode → cathodeIons in the electrolyte · electrons in the external circuit

Heiwit develops the energy storage system — battery pack, BMS, electronics, inverter and integration — and selects and qualifies the cells used.

04 / Technology comparison

Sodium-ion and LFP.

Two technologies with different characteristics. Lithium iron phosphate offers more energy per kilogram; sodium is particularly attractive for stationary storage.

Indicative comparison between LFP and sodium-ion cells
Parameter	Lithium iron phosphate · LFP	Sodium-ion
Energy density	120–180 Wh/kg, typical	100–160 Wh/kg, typical depending on chemistry
Cycle life	High	High; depends on the cell and test conditions
Low temperature	Marked capacity loss below zero	Limited loss, especially in polyanionic chemistries
Thermal stability	Good, among the best of the lithium chemistries	Good, with additional margin in polyanionic chemistries
Raw materials	Lithium, iron and phosphorus	Sodium and iron; no lithium or cobalt in the cells described
Deep discharge and storage	The cell does not tolerate zero volts; copper anode current collector	The cell can tolerate zero volts with aluminium current collectors, useful for storage and transport
Applications	Light mobility and energy storage with weight and volume constraints	Stationary storage, harsh climates and long service life

Gli intervalli di densità sono valori tipici di mercato, non la specifica di una singola cella o della batteria Heiwit. Le caratteristiche di cella non sostituiscono i limiti operativi del sistema completo. A parità di capacità, il sodio richiede più spazio: la disponibilità va verificata in sopralluogo.

Energy density and service life in energy storage

Supplied photograph of the Heiwit system with battery, inverter and solar panel

05 / The complete system

Energy under control.

Battery, BMS and inverter work together. The Heiwit installer network defines the configuration best suited to your system and your needs.

With the Heiwit app you can monitor the state of charge, efficiency and performance of the system in real time from your smartphone or tablet.

Find an installer

06 / Applications

From homes to businesses.

Le configurazioni con batterie in parallelo si adattano a esigenze di autoconsumo, ampliamento dell’impianto e accumulo commerciale o industriale.

Residential

Store the solar energy produced during the day to use it in the evening and at night. Backup functions to be defined in the system configuration.

Solar PV and battery storage

Retrofit

Add battery storage to your existing solar PV. The Heiwit inverter connects on the AC line and the existing one can remain installed.

Existing systems

Commercial and industrial

Multiple configurations for three-phase users, including in non-air-conditioned plant rooms. Sizing based on actual consumption and conditions.

Let's discuss your project

BESS

Larger solutions for industrial applications, with dedicated sodium-ion systems up to the 1 MWh class.

Discover our BESS

07 / Safety and compliance

From cell testing
to the complete system.

Safety depends on the cell chemistry, the pack, the BMS, the electronics and the quality of the installation. Thermal stability concerns the cathode and electrolyte, not sodium alone.

Explore the qualification tests

Nail penetration
Overload
Short circuit
Squash
Bake test
Thermal control up to 300 °C

Compliance and certifications

Standards, directives and subjects of qualification for Heiwit systems
Scope	Standard or directive	Subject and reference
Italian grid · VIRGO	CEI 0-21:2022 + V1:2022 + V2:2024	VIRGO kit + batteryTÜV SÜD · D 132944 0003 October 2025
Italian grid · LYBRA	CEI 0-21:2022 + V1:2022 + V2:2024 + V2/EC:2024 + V2/EC2:2025	LYBRA kit + batteryTÜV Rheinland · A3 50741827 0001 August 2026
Electrical safety	Low Voltage Directive 2014/35/EU	Inverter: EN 62109-1 and EN 62109-2 Battery: EN IEC 62040-1
Electromagnetic compatibility	EMC Directive 2014/30/EU	Inverter and battery
Battery system safety	PPP 51096A:2023Voluntary test	Battery pack and BMS

The system is CE marked. For installation outside Italy, grid connection rules and the required certificates depend on the country: request the applicable documentation.

VIRGO certificatePDF · TÜV SÜD / CEI 0-21 LYBRA certificatePDF · TÜV Rheinland / CEI 0-21 Battery datasheetPDF · Caratteristiche della batteria Battery manualPDF · Installation and use

08 / Frequently asked questions

The answers,
before you choose.

For sizing and configuration, consult the Heiwit installer network.

Find an installer

How long does a sodium-ion battery last?

La versione 2025–2026 a ossidi stratificati è stimata per oltre 6.500 cicli. Nel test a 6.500 cicli, la capacità residua è rimasta superiore al 70%. La durata in anni dipende anche da profondità di scarica, corrente, temperatura e stato di carica medio. La garanzia è di 10 anni.

Does it work at low temperatures?

La batteria si scarica da −25 a +60 °C e si carica da 0 a +60 °C. Separatamente, nei test di qualifica della cella polianionica, a −20 °C è stata conservata oltre il 90% della capacità. Sono dati riferiti ad ambiti diversi: funzionamento della batteria e prova della cella.

Can I use it with my current inverter?

Direct battery connection requires a Heiwit VIRGO or LYBRA inverter. To add battery storage to an existing system, the Heiwit inverter can be connected on the AC line while keeping the solar inverter already installed. Discover compatible configurations.

How much space is needed?

The lower energy density makes a sodium system bulkier than an LFP system of the same capacity. The installer checks the available space during the site survey; dimensions and requirements can be found in the datasheet.

Does Heiwit also make the cells?

Heiwit develops and manufactures the energy storage system — battery pack, BMS, electronics, inverter and integration — and selects and qualifies the sodium-ion cells used in its products.

How does the cost compare with a lithium battery?

Beyond the initial price, what matters is the cost per kWh cycled overall: the system cost relative to the energy exchanged over its lifetime. Lifetime, operating conditions, maintenance and installation all affect the comparison. Learn more about the method.

How can I buy it?

The batteries are sold through the Heiwit installer network. The recommended retail price (RRP) of the 10 kWh battery is €4,900 VAT included. The installer prepares the quote based on the configuration and installation required.

Is it also suitable outside Italy?

CE marking, the Low Voltage Directive and the EMC Directive apply in the European Economic Area. Grid connection rules remain national. Before installing the system in another country, request the relevant certificates from [email protected].