Plug-in or fixed: which home battery suits you?
If you are looking for a home battery, you first have to choose between two types: a plug-in home battery that you plug into the socket yourself, or a fixed home battery that an installer connects to the electrical panel. In short: the plug-in home battery is the quickest and cheapest way to get started, while the fixed battery is the choice if you want more power or want your whole house to keep running during a power cut. Below you can read exactly where the difference lies and which one suits your home.
The difference in one table
| Plug-in home battery (plug & play) | Fixed home battery | |
|---|---|---|
| Connection | Yourself, plug into an earthed socket | By an installer, permanently connected to the electrical panel |
| Power to your home | Maximum 800 W via the socket | Usually several kW, up to 6 kW or more with larger systems |
| What it covers | Base load: fridge, lighting, TV, router, laptop | Also heat pump, induction cooking and washing machine at the same time |
| Backup power | Only the appliances you connect to the backup power output | Via a changeover switch, on the circuits chosen during installation |
| Expansion | Add extra batteries, per phase | Extra battery packs or modules, per system |
| When ready | The same day | After an installation appointment |
Plug-in home battery: connect it yourself, ready the same day
You connect a plug-in home battery (also called a plug & play battery) to an ordinary earthed socket. You hang it on the wall or set it down, plug it in, pair the supplied meter with your smart meter and install the app. No electrician is needed.
Via the P1 port of your smart meter, the battery measures how much your home is consuming and generating at that moment. Based on that, it charges during the day with solar power that you would otherwise export to the grid, and supplies it back to your home in the evening. If you have a dynamic energy contract, it can also charge during cheap hours and supply power when electricity is expensive. You can read how that measurement works in our article about the P1 smart meter dongle (P1-meter).
The most important thing to know: in the Netherlands, a battery may deliver a maximum of 800 W to your home via the socket. For an average household, that covers the base load, i.e. fridge, lighting, TV, router and laptop. If the washing machine, oven or induction hob are running at the same time, the rest comes from the grid. If you want more, an installer can also put most plug-in home batteries on a dedicated circuit in the electrical panel. A Marstek Venus E, for example, then delivers 2,500 W instead of 800 W.
Plug-in home batteries are almost always modular. You start with one battery and later add an expansion module or a second battery alongside it. View the overview of plug & play home batteries or the separate expansion modules.
Fixed home battery: more power and backup power for the whole house
A fixed home battery is connected to the consumer unit with fixed wiring by a qualified installer. That is more work, but you get three things in return.
More power. There is no 800 W limit. A fixed battery charges and discharges at several kilowatts; with a system such as the Marstek Venus X, for example, 6 kW continuously. This lets the heat pump, induction cooking and the normal household run on your own electricity at the same time, and the battery fills up faster during cheap hours.
Backup power for the whole house. In the event of a power cut, a fixed system with a changeover switch switches over within milliseconds, so the whole house keeps running. A plug-in home battery only keeps the appliances going that you connect directly to the backup power output.
Integration with your solar panels. Fixed batteries come in two types. AC-coupled systems do not sideline your existing panels and inverter; the battery is simply added alongside them. DC-coupled systems work together with a hybrid inverter, which is particularly interesting for a new installation or if your inverter is due for replacement. View the overview of fixed home batteries.
Pay attention to your connection: many fixed systems are either single-phase or three-phase. You can read which one you have and why it matters in our article about single-phase and three-phase.
Which one suits your situation?
You have solar panels and mainly want to use your own electricity in the evening. A plug-in home battery of 5 to 10 kWh captures the daily surplus and is in use the same day. Most customers start here.
You rent, or you do not want anything permanently connected. Then the plug-in home battery is the practical choice. If you move, you simply take it with you.
You have a dynamic contract and no solar panels. A plug-in home battery works in that case too: charging during cheap hours, supplying during expensive hours. With a dedicated circuit you get more out of it, because the battery then charges faster and supplies more.
You have a heat pump, induction hob or charging point and want to run it on your own electricity. Then you will quickly hit the limit with 800 W. Choose a fixed battery, or a plug-in home battery on a dedicated circuit.
You want the whole house to keep running during a power cut. That requires a fixed battery with a changeover switch.
You are building a new home or replacing your inverter. Then a fixed battery with a hybrid inverter is often the logical choice, because everything is properly matched in one go.
Not sure? Request a no-obligation quote and we will look at your consumption, your connection and your solar panels. Already know what you want? View all models under buy a home battery.
Frequently asked questions
Can I start with a plug-in home battery and switch to fixed later?
Yes. Many plug-in home batteries, such as the Marstek Venus E, can later be put on a dedicated circuit by an installer. You keep the same battery, but without the 800 W limit.
Do I need a smart meter for a plug-in home battery?
In practice, yes: the battery is controlled based on data from the P1 port. If you do not have a P1 port, a CT clamp in the electrical panel can take the same measurement. In the Netherlands, your grid operator will install a smart meter free of charge.
Can I use a plug-in home battery in Belgium?
Yes, if the model is Synergrid-approved. This is stated with our products; also see our article on the Synergrid approval of Marstek.
How many batteries can I link together?
That differs per brand. With Marstek, you can link up to three batteries per phase; with other brands, you place expansion modules under or next to the main unit. The maximum capacity is stated on each product page.
What does installing a fixed battery cost?
That depends on the system, your electrical panel and whether you want backup power. We work with installation via a quote, so you know exactly where you stand in advance.