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MARSTEK Venus E MAX is a plug-in storage unit with no inputs for panels: it charges from the home grid and returns AC current from the same port. It serves anyone who already has a solar system and wants to hold onto the midday sun for the evening, or anyone on an hourly tariff who wants to buy at night what they consume during the day. In base mode it feeds in within the threshold for plug-in systems; a more aggressive mode goes beyond that, and at that point installation moves past simple plug-and-go.
It has a separate outlet that keeps giving power when the grid fails, with enough power to handle several appliances together, not just the router. Up to three units go in parallel with the SmartBox, even on a three-phase system. It has an IP65 protection rating.
It's for anyone wanting a large reserve with no panels to connect to the unit, perhaps to pair with the same brand's portable EV charger. Anyone with panels to attach directly to the battery should look at a model with its own solar input.
| Parameter | Value | Source |
|---|---|---|
| Weight | 86.0 kg (189.6 lb) | manufacturer website |
| Nominal capacity | 10.048 kWh | Declared by the brand |
| Depth of discharge | 90 % | Declared by the brand |
| Cell chemistry | LFP (lithium iron phosphate) | Declared by the brand |
| Expandable | Yes | Declared by the brand |
| Maximum expanded capacity | 30 kWh | Declared by the brand |
| Battery voltage | 32 V | Declared by the brand |
| Feed-in limit | 800 VA | Declared by the brand |
| Grid charging | Yes | Declared by the brand |
| Maximum charge power | 3.6 kW | Declared by the brand |
| Backup power | EPS (brief interruption) | Declared by the brand |
| Backup output | 3600 W | Declared by the brand |
| Rated cycles | 10000 cicli | Declared by the brand |
| Warranty | 10 anni | Declared by the brand |
| Round-trip efficiency | 92 % | Declared by the brand |
| Ingress protection | IP65 | Declared by the brand |
| Minimum temperature | -20 °C | Declared by the brand |
| Maximum temperature | 60 °C | Declared by the brand |
| Cell supplier | — | Not declared |
| Inverter included | — | Not declared |
| Maximum solar input | — | Not declared |
| MPPT trackers | — | Not declared |
| Dynamic tariffs | — | Not declared |
| Switchover time | — | Not declared |
| Capacity at end of cycle life | — | Not declared |
| Guaranteed throughput | — | Not declared |
| Guaranteed remaining capacity | — | Not declared |
| Standby consumption | — | Not declared |
| Mounting | — | Not declared |
| Cell heating | — | Not declared |
| Noise level | — | Not declared |
| Works without internet | — | 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 |
| App required for setup | — | Not declared |
| Declared standards | — | Not declared |
| Battery passport | — | Not declared |
| Carbon footprint | — | Not declared |
| Recycled content | — | Not declared |
| Official list price | — | Not declared |
The rest of the data comes from one page 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.
