Marstek VENUS E Pro
An all-in-one plug-in battery with four solar inputs, 1.5 kW of bidirectional power and 1.5 kW of backup, starting at 2.08 kWh and expandable to 12.48 kWh.
- Best for adding solar storage
- Plug-in battery
- 2.08 to 12.48 kWh
- 2.4 kW solar input
- Made by Marstek.
- Capacity: 2.08 kWh in the host unit, which holds the inverter, with up to five extra 2.08 kWh batteries for 12.48 kWh in total.
- Solar: four MPPT inputs for up to 2.4 kW of panels, with 99.8% MPPT efficiency.
- Power: 1.5 kW bidirectional AC power, with 0.8 kVA or 1.5 kVA grid output, and 1.5 kW backup power with under 10 ms switchover.
- Rules: whether you can use it as a plug-in battery depends on your country.
Not tested by us
We have not tested the Marstek VENUS E Pro. The figures on this page come from the sources listed at the end of the page, checked on 13 November 2026, and we do not show prices. "Best for" is based on what the maker says the product is designed for, not on our own tests.
Key figures
12.48 kWh
Maximum with five extra batteries
2.4 kW
Solar input, 4 MPPT
1.5 kW
Bidirectional AC power and backup
Specifications
Last checked on 13 November 2026. The grey text under each name explains what the value means. To see it next to other products, compare it in our comparison tool.
| Specification | Value |
|---|---|
| Storage | |
| CapacityHow much energy the battery stores. Bigger means longer runtime or more of your own solar power used later. | 2.08 kWh in the host unit (41.6 V, 13S). Each additional battery (model MST-E2.0ST) also holds 2.08 kWh. |
| Battery chemistryLFP (lithium iron phosphate) cells are known for long life and stable behaviour with heat. | Lithium iron phosphate (LiFePO₄) |
| Depth of dischargeHow much of the battery can be emptied without harming it. 90% means 10% is kept in reserve. | 90% |
| Cycle lifeHow many full charge and discharge cycles the cells are rated for before they hold less than the stated share of their original capacity. | More than 10,000 cycles at 25 °C. The product page adds up to 15 years of service. |
| ExpansionExtra battery units that add storage to the same system. | 0 to 5 additional batteries, so 2.08 to 12.48 kWh in total. The additional batteries stack on the host unit without tools, according to Marstek. |
| Power | |
| AC output, grid-connectedThe lower output allowed when it feeds power into the home's circuits or the grid. | 0.8 kVA or 1.5 kVA rated output (3.48 A or 6.53 A at 230 V, 50 Hz). Power factor above 0.99 by default. |
| Backup outputA separate socket that keeps selected devices running when the grid is down. | 1.5 kVA rated and peak, 230 V / 50 Hz, through an off-grid socket (UK standard socket on the UK datasheet, European socket on the EU one) |
| Backup switchover (EPS)What happens when the grid fails. EPS means it takes over automatically. | Under 10 ms, according to the product page |
| AC charging inputHow fast it charges from a wall socket or the grid. | 1.5 kVA rated input power. The product page mentions 1.5 kW AC charging from the grid. |
| Efficiency and standby useLosses when charging, discharging and doing nothing. | More than 94.5% maximum efficiency between the battery side and the AC side. Standby use is not stated. |
| Solar | |
| Solar inputHow much solar panel power it accepts. A higher figure fills the battery faster on a sunny day. | Four MPPT inputs, up to 2.4 kW in total, 16 to 60 V, up to 20 A per input, MC4 connectors, 99.8% MPPT efficiency |
| Grid connectionThe supply type it is built for. Check it matches your home's supply. | AC-coupled, single phase (L/N/PE). Marstek says it works with an existing solar system and with mainstream smart meters, with a 3 second response at ±10 W. |
| Solar and off-grid | |
| Works with solar panelsWhether you can charge it from solar panels. Yes means a built-in solar input or a compatible solar setup; read the detail for the voltage and power limits. | Yes: four built-in MPPT inputs, 16 to 60 V, up to 2.4 kW of panels (MC4 connectors). |
| Off-grid useWhether the maker describes it running with no grid connection at all, for example in a cabin, van or off-grid home. Backup only means it covers power cuts but needs the grid the rest of the time. | Partly: 1.5 kVA backup output through a socket in a power cut; Marstek describes a grid-connected system, not a stand-alone off-grid one. |
| Connection and housing | |
| Dimensions (W × D × H)Check the space before you buy, including room around it for airflow and cables. | Host unit 450 × 340 × 220 mm and each additional battery 450 × 340 × 168 mm, as listed by Marstek (axis order not stated) |
| WeightMatters for lifting, wall mounting and moving it. | Host unit 25.5 kg, each additional battery 18.5 kg |
| Protection ratingIP ratings show protection from dust and water. IP55 and IP65 are rated for outdoor-style exposure; check the installation guidance. | IP65 |
| Operating temperatureThe range it is rated to work in. Cold and heat can reduce performance. | -20 to 60 °C (storage -30 to 85 °C) |
| Noise levelFan noise while working. | Under 30 dB, with fanless natural cooling |
| Operating altitudeThe maximum height above sea level it is rated to work at. | Up to 2,000 m |
| DisplayWhether the unit has its own screen showing charge level and power in and out. | LED |
| ConnectivityHow you monitor and control it, usually through an app. | Bluetooth, Wi-Fi and Ethernet; Marstek app with free over-the-air updates, plus an open API and Modbus |
| Warranty | |
| WarrantyThe period the maker covers. Read the terms: conditions and capacity guarantees differ. | 10 years |
Compatible with
What Marstek says this product works with. Anything not listed here is not confirmed.
- Smart meters
- Marstek says the system works with mainstream smart meters or a CT clamp for anti-feed-in control and zero export. It does not name models on the pages we read.
- Marstek portable EV charger
- Marstek says it works with its own portable EV charger, with solar-first, scheduled and off-peak charging modes.
- Dynamic and time-of-use tariffs
- Marstek says its AI energy manager works with fixed time-of-use and dynamic tariffs from more than 840 European electricity providers.
- Third-party energy management
- Marstek says an open API and Modbus connect third-party systems such as Home Assistant.
Rules where you live
Rules for plug-in batteries differ by country. Marstek publishes a UK datasheet with a UK standard socket on the backup output, but we could not confirm how the unit may be connected in Great Britain. There, plug-in solar kits of up to 800 VA have been legal since 27 August 2026, but the rules exclude plug-in batteries.
Check the rules, incentives and tariffs for your own country in our country guides.
Strengths and things to check
Strengths
- Four MPPT inputs for up to 2.4 kW of panels
- 1.5 kW bidirectional power and 1.5 kW backup with under 10 ms switchover
- Modular from 2.08 kWh to 12.48 kWh
- IP65, -20 to 60 °C and under 30 dB
- 10-year warranty and more than 10,000 cycles
Worth checking before you buy
- Whether it counts as a plug-in product depends on your country: check the rules below
- The host unit holds only 2.08 kWh, so reaching 10 kWh or more needs several extra batteries
- The datasheet lists a 0.8 kVA or 1.5 kVA grid output without saying which applies where
- Marstek gives the dimensions without stating which number is width, depth or height
Change log
We record changes to this page here, so you can see when figures such as the warranty were last updated.
- 13 November 2026
- Page published. Warranty at publication: 10 years (Marstek product page).
Where this information comes from
We have not tested the VENUS E Pro. Every figure above comes from Marstek's VENUS E Pro product page and its UK datasheet (PDF on Marstek's download centre), last checked on 13 November 2026. The product page's specification tab was empty, so size, weight and most electrical values come from the datasheet. A value these sources do not state is shown as not stated.
We do not show prices, because they change often and differ between sellers. We also leave out Marstek's savings and payback figures, which are theoretical values from its own model.
- Manufacturer Marstek VENUS E Pro datasheet (UK version, PDF, download centre)
- Manufacturer Marstek VENUS E Pro product page
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Common questions about Marstek VENUS E Pro
Can I use the Marstek VENUS E Pro as a plug-in battery in my country?
It depends on local rules. Marstek markets it as a plug-in battery. In Great Britain, plug-in solar kits up to 800 VA are legal since 27 August 2026 but the rules exclude plug-in batteries. Check our country guides.
How much storage and solar can the VENUS E Pro take?
The host unit holds 2.08 kWh and takes up to five extra 2.08 kWh batteries, 12.48 kWh in total. Marstek lists four MPPT inputs and up to 2.4 kW of solar input.
Does the VENUS E Pro work during a power cut?
Yes. Marstek says it switches to backup power in under 10 ms and supplies 1.5 kVA through its off-grid socket.
Related guides
How much could a battery save you?
Our calculator uses your own usage and tariff to estimate what a home battery could save, with conservative assumptions.