Photo from the manufacturer
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STREAM Ultra X is an all-in-one balcony storage unit: battery and grid-feed inverter share the same body, which connects to the grid through the dedicated cable and stays within the feed-in limit set by your country. The solar inputs are independent of each other, so panels can be oriented on different roof slopes without shade on one side penalizing the others. Growing over time doesn't need a second inverter: several units of the same type can be chained together, each with its own battery, or spread across different points of the balcony if the panels face different directions.
Besides feeding solar energy into the grid, the main body also recharges directly from the home outlet, so the battery fills up even on days without sun. Basic control also works without a cloud connection, staying on the home's local network; remote control, consumption history and automatic optimization around hourly tariffs need the app connected to the internet instead, and that last feature requires a separate subscription. The system also talks to third-party devices that use the Matter protocol, besides EcoFlow accessories for reading home consumption.
It's built for anyone who wants to start with one balcony and grow by adding more units over time, and for anyone who isn't satisfied with just the app to check that the system works. Mounting, though, calls for a bracket fixed to the wall with anchors: anyone renting needs the landlord's permission before drilling.
official manufacturer list price — on nominal capacity
| Parameter | Value | Source |
|---|---|---|
| Weight | 38.8 kg (85.5 lb) | manufacturer website |
| Nominal capacity | 3.84 kWh | Declared by the brand |
| Cell chemistry | LFP (lithium iron phosphate) | Declared by the brand |
| Expandable | Yes | Declared by the brand |
| Maximum expanded capacity | 23 kWh | Declared by the brand |
| Battery voltage | 19.2 V | Declared by the brand |
| Feed-in limit | 800 VA | Declared by the brand |
| Inverter included | Yes | 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 |
| Maximum charge power | 2.3 kW | 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 |
| Mounting | Wall mounted | 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 |
| Local control | Local network | Declared by the brand |
| Open protocols | Matter | Declared by the brand |
| Declared standards | CE | Declared by the brand |
| Official list price | 1799 € | Declared by the brand |
| Usable capacity | — | Not declared |
| Depth of discharge | — | Not declared |
| Cell supplier | — | 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 |
| Cell heating | — | Not declared |
| Noise level | — | Not declared |
| Home Assistant integration | — | Not declared |
| Where the data is hosted | — | Not declared |
| Remote updates | — | Not declared |
| App required for setup | — | 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.
