Part of the guide Home battery, EV charger and electric heating
Short answer: you plug a plug-and-play home battery into a socket on a dedicated circuit, link it to your smart meter via a P1 meter and it is up and running within half an hour, without an installer, for € 659 (2 kWh) to € 2,399 (10 kWh). A fixed home battery is connected by an installer to the consumer unit or to a hybrid inverter, can be larger and more powerful (10 to 20 kWh, 3-phase, sometimes backup power) and costs € 6,000 to € 10,000 including installation. For most households with solar panels on a single-phase or standard 3-phase connection, plug-and-play does the same job for a third of the price. Choose fixed if you want backup power, have high consumption or are integrating the battery into a new solar system with a hybrid inverter.
The difference in one table
| Plug-and-play (for example Marstek Venus E) | Fixed home battery (AC- or DC-coupled) | |
|---|---|---|
| Connection | Earthed socket on a dedicated 16 A circuit; P1 meter in the smart meter | By an installer on a dedicated circuit in the consumer unit or on a hybrid inverter behind the panels |
| Installation | Yourself, 30 minutes; check whether registration is required in your country | Installer, half a day to a full day; often a new circuit or changes to the consumer unit |
| Capacity | 2 to 10 kWh per unit, expandable with a second unit | 5 to 20 kWh, modular |
| Power | 800 W (Mini), 2.500 W (Venus E 3.0), 3.600 W (Venus E Max) | 3 to 10 kW, controlled per phase on 3-phase |
| Zero on the meter | Yes, via the P1 meter on the total measurement; on 3-phase the meter nets the phases together | Yes, via its own metering |
| Backup power during an outage | No (the Venus E does have a separate backup output for appliances plugged into it) | Possible with a backup box, at extra cost |
| Dynamic tariff | Yes, charging and discharging on hourly prices via the app | Depends on the inverter and energy management system |
| Price | € 659 (2 kWh) tot € 2.399 (10 kWh), circa € 235 per kWh | € 6,000 to € 10,000 incl. installation for 10 kWh, around € 600 to € 900 per kWh |
| Moving house | Take it with you: just unplug it | Usually stays behind or costs money to dismantle |
How a plug-and-play battery works
The battery has a built-in inverter and is connected to the socket like an ordinary appliance. The P1 meter in the smart meter reports every second how much electricity your home is drawing or feeding back. If your roof produces more than you use, the battery charges exactly that surplus; if you use more than the roof produces, the battery feeds exactly the shortfall back into the house. So the socket works in two directions. Because the control works on the total measurement, it does not matter which circuit or phase the battery is on: with a 3-phase connection the smart meter offsets the phases against each other and the balance comes out at zero.
What you need: an earthed socket within reach of the meter's P1 port (the P1 meter is connected to the smart meter by a cable and communicates wirelessly with the battery), a dedicated 16 A circuit so that the 2,500 W of charging and discharging does not coincide with a washing machine on the same circuit, and a dry, frost-free location. The Venus E may be installed outdoors (IP65) but performs best between 5 and 35 °C.
What you can do yourself
Connecting a plug-in appliance is generally not installation work; you do not need an installer for it. You plug the P1 meter into the smart meter's P1 port; that port is intended for this and users may use it themselves. Rules for registering generation or storage systems differ per country; in many countries you have to register the system with your grid operator, just as with solar panels, so check what applies where you live. If there is no dedicated circuit for the socket yet, that is the only job for an electrician, in line with local electrical regulations; an extra circuit costs roughly € 150 to € 300.
When a fixed home battery is better
- Backup power. If you want your fridge, boiler and lighting to keep running during a power cut, you need a fixed system with a backup box that disconnects the house from the grid. A plug-and-play battery switches off when the grid fails (this is mandatory, to protect engineers working on the grid).
- High consumption and many panels. Above 15 kWp of panels and 8,000 kWh of consumption, 3 to 10 kW of charging power and 15 kWh or more make sense; that requires a fixed connection.
- New solar system. If you are installing panels with a hybrid inverter now, a DC-coupled battery behind that inverter is more efficient (one conversion fewer) and more neatly integrated.
- Business or owners' association. For larger connections and shared installations, plug-and-play is not an option.
For all these situations we can supply a tailored package via our quote request; Instalpunt does not install, so have a qualified local installer do the installation. See also our installation service.
How big should it be?
That depends on your consumption outside sunlight hours and on what your panels have left over; for most families it comes to 5 kWh. The calculation is in How many kWh of home battery do I need?. The models: Venus E Mini 2 kWh (€ 659), Venus E 3.0 5.12 kWh (€ 1,098, collection in Alblasserdam (Netherlands) € 1,100) and Venus E Max 10 kWh (€ 2,399), all including P1 meter, in the · .
Safety and lifespan
The Venus E series uses lithium iron phosphate (LFP): more thermally stable than the lithium-ion in phones and cars, with 6,000 charge cycles, which with daily use comes to more than fifteen years. The units have their own battery management system that switches off in case of excessive temperature, overload or grid failure. Do not place the battery in a closed cupboard without ventilation or in direct sunlight. The Marstek batteries come with a 10-year manufacturer's warranty; see our warranty page.
Frequently asked questions
Does a plug-and-play battery work on a 3-phase connection?
Yes. The smart meter nets the three phases into one balance; the battery on one phase compensates the total. For the meter it does not matter which phase you consume on and which you feed back on.
Can I combine two plug-and-play batteries?
Yes, two Venus E units work together with the same P1 meter and share the charging and discharging. Use two separate circuits.
Is there a subsidy for a home battery?
That depends on where you live. Subsidies or incentives may be available in your country or region — check your national scheme. For the Netherlands, see home battery subsidies in the Netherlands.
What happens during a power cut?
A plug-and-play battery switches off and comes back on as soon as the grid is restored. If you want backup power, choose a fixed system with a backup box, or use the separate backup output of the Venus E for a single appliance.