W1

Last verified 2026-10-06.

• BIWATT's release describes the W1, listed together with the W1 Pro, as an all-in-one sodium-ion unit.
• The release, dated 28 November 2024 and issued for Solar Solutions Dusseldorf, lists the W1 among BIWATT's key products and gives no launch date, price or availability for it.
• BIWATT says it scaled commercial deployment of its sodium-ion storage systems across Europe, Asia-Pacific and North America in 2024, but that statement covers its range in general, not the W1 specifically.
• Official W1 technical documentation is now readable and names PNA-4.5-02. The page remains unscored: usable capacity is not established, battery continuous power remains unresolved, cycle life lacks a retained-capacity endpoint, round-trip efficiency is not established, governing W1 warranty terms remain unconfirmed and no exact certification listing was independently recovered.
• The source documents identify W1 PNA-4.5-02 separately from W1 Pro and W2. Their exact rows, firmware/revision limits and rated-versus-usable energy boundaries are kept separate. The publication model field remains unchanged and adjacent-model ratings are not transferred.
• The W-series technical sheet names W1 as PNA-4.5-02, single phase and off-grid. Its W1 column gives 4.5 kWh battery capacity, 45 V rated battery voltage and 1C maximum continuous charge/discharge current. Measured usable capacity is not established; battery-only continuous power in kW and simultaneous inverter/battery operating conditions remain unresolved. The publication model field is unchanged and no scored configuration is selected.
• The W1 off-grid AC row is labelled nominal apparent power but uses the unit W for 5,000 W, alongside 230 Vac and 21.7 A maximum output current. This label/unit ambiguity is retained rather than converted into a continuous battery-power guarantee, an on-grid export rating or a surge rating. The W1 manual repeats the same output basis. W1 Pro and W2 values are not transferred.
• The exact W1 PV input rows list maximum DC power 5,000 W, maximum DC input voltage 450 V, one MPPT and a 120-400 V MPPT range. The listed 97% maximum efficiency is an inverter/system maximum, not measured battery round-trip efficiency. Round-trip efficiency is not established.
• The maker gives 5,000 cycles at 25 +/- 2 C, 0.5C charge/discharge and 80% DoD. No retained-capacity endpoint or governing performance warranty is established, so these cycles do not support an end-of-life retention claim or a usable-energy calculation.
• The W1 sheet and Issue 04 manual agree on IP21, forced-air cooling, 85 kg weight, 600 x 880 x 165 mm dimensions, charging from -20 C to +55 C and discharge from -30 C to +55 C. The manual separately requires a sheltered, dry, ventilated location and gives a -20 C to +55 C installation ambient range. Its salt-damage boundary includes within 500 metres of the coast or sea-breeze exposure; the lower technical discharge floor does not waive placement requirements.
• The W1 sheet lists RS485/CAN, APP/LCD interaction and FOTA/local updates with remote/local maintenance. The Issue 04 manual lists local firmware updates and local maintenance, while describing an optional Wi-Fi stick and app for cloud monitoring. Remote firmware-update availability and version/accessory conditions remain held pending reconciliation; interface presence does not establish an open API, VPP service or firmware-security assurance.
• The sheet says W1 can support an EV AC charger with an additional purchase. This does not establish a charger in the supplied system, an exact accessory model or local availability. The manual permits capacity expansion using BIWATT batteries and illustrates R2; it does not justify importing the family headline of 60 kWh as an exact W1 tested configuration.
• The W1 technical rows cite EN 62619 and EN 62109-1/-2 and EMC standards as maker CE compliance statements. No exact independently recovered certification listing or local grid approval is established; W1 is explicitly off-grid in this sheet. Battery chemistry and general safety marketing are not independent fire-test results.
• The current maker-linked warranty policy explicitly lists R2, R3, R5 and I3, but does not name W1. Five-year coverage from those families is not transferred. Governing W1 warranty terms remain unconfirmed; manual exclusions and warnings do not establish duration, retention, claims, transfer or labour/freight remedies.
• The new sources recover exact W1 technical documentation and reader limits, not a sale/shipping or regional stock confirmation. Usable capacity, continuous battery power, cycle retention, round-trip efficiency, governing warranty and exact certification remain promotion gates. The older announcement, evidence-only state and public identity fields are preserved.

• BIWATT official press release via PR Newswire, 28 November 2024https://www.prnewswire.com/news-releases/biwatt-showcases-advanced-sodium-ion-energy-solutions-at-solar-solutions-dusseldorf-302318128.html

  BIWATT's own release, issued for Solar Solutions Dusseldorf, lists the W1 as an all-in-one sodium-ion unit and describes its 2024 sodium-ion deployment.

• BIWATT PowerNest W-series datasheet, public document 39https://www.biwattpower.com/gateway/front/website/document/39?lang=en

  Physical page 3 is the exact W1 PNA-4.5-02 column. Image-only rows visually read; W1 Pro/W2 ratings excluded. No printed revision established.

• BIWATT PowerNest W1 PNA-4.5-02 user manual, public document 6https://www.biwattpower.com/gateway/front/website/document/6?lang=en

  Issue 04, 10 January 2025. Relevant identity, technical, installation/environment, interface, expansion and optional networking pages read. Local-update rows differ from newer sheet FOTA wording.

• BIWATT current product warranty, public document 31https://www.biwattpower.com/gateway/front/website/document/31?lang=en

  Complete same-day policy reused. Explicit covered families R2/R3/R5/I3 do not establish W1 entitlement. Exact W1 governing instrument remains required.