Photo from the manufacturer
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STREAM Ultra is a storage tower for a balcony or for retrofitting an existing solar system: battery and bidirectional inverter share the same body, which connects to the home outlet - or, where regulation requires it as in the United Kingdom, through an electrician - and to the panels through four independent solar inputs. Excess energy is fed into the grid within your country's limit, or powers connected appliances; when the sun isn't enough, the device can also recharge by drawing from the grid.
It grows by adding up to five identical units: stacked in the same spot - with the safety anti-tip bracket, never past two levels - or spread across different rooms while staying synced on the same Wi-Fi network. The app is for pairing the devices and setting everything up the first time; basic controls stay available over Bluetooth even without internet, but controlling a whole system with several units needs the connection. It has no fans, so it doesn't add noise while it works, and it connects directly to the main hourly energy price providers to shift charging and discharging to the more convenient hours.
It's built for anyone who has, or plans to have, several panels to connect and wants room to keep adding more over time, and for anyone who wants to be able to control it even when the home Wi-Fi doesn't reach the balcony. If the electrical grid is interrupted, the switch to the battery isn't instant: it doesn't replace an uninterruptible power supply, and equipment that can't tolerate any interruption should be connected elsewhere.
official manufacturer list price — on nominal capacity
| Parameter | Value | Source |
|---|---|---|
| Weight | 23.1 kg (50.9 lb) | manufacturer website |
| Power supply | 230 V / 50 Hz | manufacturer website |
| Nominal capacity | 1.92 kWh | Declared by the brand |
| Cell chemistry | LFP (lithium iron phosphate) | Declared by the brand |
| Expandable | Yes | Declared by the brand |
| Battery voltage | 19.2 V | Declared by the brand |
| Feed-in limit | 800 VA | Declared by the brand |
| Inverter included | No | Declared by the brand |
| Maximum solar input | 2000 W | Declared by the brand |
| MPPT trackers | 4 | Declared by the brand |
| Grid charging | Yes | Declared by the brand |
| Dynamic tariffs | Built in | Declared by the brand |
| Backup power | EPS (brief interruption) | Declared by the brand |
| Backup output | 1200 W | Declared by the brand |
| Rated cycles | 6000 cicli | Declared by the brand |
| Warranty | 10 anni | Declared by the brand |
| Ingress protection | IP65 | Declared by the brand |
| Minimum temperature | -20 °C | Declared by the brand |
| Maximum temperature | 55 °C | Declared by the brand |
| Works without internet | With limitations | Declared by the brand |
| App required for setup | Yes | Declared by the brand |
| Declared standards | CE | Declared by the brand |
| Official list price | 1299 € | Declared by the brand |
| Usable capacity | — | Not declared |
| Depth of discharge | — | Not declared |
| Cell supplier | — | Not declared |
| Maximum expanded capacity | — | Not declared |
| Maximum charge power | — | Not declared |
| Switchover time | — | Not declared |
| Capacity at end of cycle life | — | Not declared |
| Guaranteed throughput | — | Not declared |
| Guaranteed remaining capacity | — | Not declared |
| Round-trip efficiency | — | Not declared |
| Standby consumption | — | Not declared |
| Mounting | — | Not declared |
| Cell heating | — | Not declared |
| Noise level | — | Not declared |
| Local control | — | Not declared |
| Open protocols | — | Not declared |
| Home Assistant integration | — | Not declared |
| Where the data is hosted | — | Not declared |
| Remote updates | — | Not declared |
| Battery passport | — | Not declared |
| Carbon footprint | — | Not declared |
| Recycled content | — | Not declared |
The rest of the data comes from 2 pages on the manufacturer's site, cited row by row in the table above.
A manual or a datasheet counts as a source even when the original file is hosted elsewhere: what matters is the document, not the server. Where that happens, it is stated above.
These numbers are calculated, not stated: they have no source to cite, they have a formula you can redo. The price used is the manufacturer's list price, which is stable and the same in every country — not a shop's price on the day.
Chosen by the declared use tier and footprint, not by price: we don't publish prices.
