Both solutions can store energy for later use. However, with the same number of kilowatt hours you do not automatically get the same result. A battery can store enough energy for your evening consumption, but provide too little power to support your hob, heat pump and other appliances at the same time.
This comparison is about homes in Flanders. View your real consumption and your existing solar panels before choosing a device. This way you avoid that the choice is based solely on the price or the largest number on the packaging.
Do you live in Brussels? The Flemish reporting thresholds below do not apply there. Sibelga requests that a home battery be reported within 30 days after use. We also check the connection conditions for your chosen device and any consequences for the solar panel installation.
The first difference is how the battery is connected.
A plug-in battery, also called a plug-and-play battery, uses a socket to charge and supply energy to the indoor installation. We connect a permanent home battery directly to your electrical installation. This permanent connection requires an AREI inspection by a recognized inspection body.
Plug-in batteries often have a more limited capacity, but there are various models and extensions. Therefore, do not assume one standard capacity. The technical data sheet and the permitted configuration determine what a specific device can do.
| Part | Plug-in battery | Fixed home battery |
|---|---|---|
| Connection | Via a suitable fixed socket. | We connect the battery firmly to your electrical installation. |
| Capacity | Depending on device and permitted extensions. | Depending on the chosen system, number of devices and suitable modules. |
| Power | Limited by device, configuration and circuit. | Designed according to the inverter, grid and home. |
| Control | Check measurement and collaboration with existing devices. | Can be included in a joint energy management; compatibility remains necessary. |
| Move | Often easier to take with you, within the installation conditions. | Requires adjustment and monitoring of the permanent installation. |
Compare kWh and kW separately.
The capacity in kilowatt hours, kWh, says how much energy the battery can store. Look at the usable capacity: it may be lower than the total capacity on the package. The set reserve and charging and conversion losses influence how much energy you ultimately use.
The power in kilowatts, kW, says how quickly the battery charges or releases energy. An appliance that emits a maximum of 800 watts delivers a maximum of 0,8 kW at that moment. If your home requires 2,5 kW and the solar panels produce nothing, then in this simple example approximately 1,7 kW must still come from the grid.
If the battery can actually supply 5 kWh to your devices, then with a constant output of 800 watts this is arithmetic 6,25 hours. The same stock cannot fully meet a residential demand of 2,5 kW if the battery can only deliver 0,8 kW. More storage does not solve a power limit.
Start with what your battery needs to absorb.
Do you want to support modest basic consumption in the evening and do you have a suitable location and power circuit? Then a plug-in solution can be a practical first step. Even if you want to move later, the option of taking the device with you can be interesting.
Do you want to support higher powers or have solar panels, battery, heat pump and charging station controlled together? Then a fixed installation deserves a thorough comparison. A fixed connection in itself does not guarantee smart collaboration: the measurement, control and compatibility must also be designed for this.
Use a series of 15-minute readings from your digital meter to see how much you inject during the day and how much you withdraw later. View regular weekdays and weekends. A large annual consumption says little about the power and storage you need on an average day.
At Laadnatie we compare the 2400 AC+ with battery modules and complete 4000 Mix devices. We install it professionally with a suitable fixed connection. We choose the Mix Pro when the inputs for directly connected solar panels are useful. The device name alone does not determine how the complete installation is performed.
Please check the exact model and measurement solution.
To connect to the Belgian distribution network, a plug-and-play device must be homologated according to Synergrid C10/26. We check the exact device reference and configuration against the official list. A CE marking and EU declaration of conformity do not replace this supply networkwork approval.
If the plug-in battery can supply power to the grid, the prescribed measurement and automatic power control are part of the homologated combination. They limit the joint injection to the permitted injection power of the solar panels. Even without solar panels, the battery may not be fed back into the grid in an uncontrolled manner.
Since 15 October 2025, the P1 port of the digital meter may be used for power management at the small production plants concerned, as an alternative to the sensor provided for this purpose. Choose a compatible measuring dongle and check which configuration the manufacturer and homologation allow.
Do you already have a charging station or other meter control? Then we look at how the measurements are shared and which control controls the battery. Two separate apps that both try to use the same solar power surplus do not constitute joint energy management.
A plug does not make the electrical check in advance superfluous.
According to the FPS Economy, connect the device to a suitable permanent socket and avoid extension cords and power strips. We assess the circuit and other connected power before installation. A separate circuit is recommended; for permanent installation in a home, it is mandatory from 2.600 watts.
Choose an accessible, well-ventilated location that meets the manufacturer's requirements. Do not place the battery in a locked cabinet without ventilation or where it obstructs passage. The connection to an existing suitable socket does not in itself require any inspection before use. An important electrical adjustment, such as a new separate circuit, is.
When do you report a plug-in battery to Fluvius?
With a digital meter, registration within 30 days is mandatory as soon as the combined inverter power on the same connection is 800 watts or more. Two plug-in appliances, each with an inverter of 600 watts count together as 1.200 watts: you must register them even without fixed solar panels.
In the case of a plug-in battery in addition to an already reported fixed installation, this obligation also applies as soon as the power of the entire installation is 800 watts or more. So look at the entire configuration, even if each individual device remains below the threshold.
With an analog meter you can report any plug-and-play device within 30 days after first use, regardless of power. Fluvius then has a digital meter installed. Below the reporting threshold with a digital meter, Fluvius still recommends registration.
Inspection and registration with the grid operator are mandatory for a fixed home battery. Schedule the notification immediately after the positive inspection. If you have existing solar panels or if we are replacing the inverter at the same time, we will also look at that adjustment and the total configuration.
Compare these five points before you buy.
Compare concrete configurations. A separate device price means little if you also need a suitable circuit, measurement, extra modules or technical adjustments. A realistic choice also makes it clear what the battery can do on your consumption profile.
- Determine how much usable energy you want to shift from the day to the evening.
- Check the charging and discharging power that suits your simultaneous consumption.
- View location, circuit, grid type and applicable installation conditions.
- Together we look at how the battery works with your solar panels, charging station and other controls.
- Compare the full price, warranty, support and possible emergency power function.
Short answer
Frequently asked questions
Can I use a plug-in battery in Flanders?
Yes, if the device meets the applicable conditions. We check the exact model on the Synergrid C10/26 list and assess whether your socket and circuit are suitable. Follow manufacturer's instructions when using. A CE marking alone is not sufficient for the required grid approval.
Do I have to register two plug-in appliances of 600 watt each?
Yes. The combined inverter power on the same connection is then 1.200 watts. Even without fixed solar panels, the reporting obligation applies within 30 days. The limit of 800 watts does not apply separately per device.
Do I have to have my home re-inspected if I connect a plug-in battery?
Connecting the appliance to a suitable existing socket does not in itself require any inspection before use. An important change to the electrical installation, such as an additional separate electrical circuit, must be inspected by a recognized inspection body.
Can my plug-in battery use the P1 port?
Since October 15 2025, the P1 port may be used for power control of the small production plants concerned. Choose a homologated device with a compatible measuring solution and follow the manufacturer's conditions.
Will I have power with a plug-in battery during a breakdown?
Don't automatically assume that. Any separate emergency power output only supplies the devices that may be connected to it according to the manual. To supply home circuits during a mains failure, you need an installation designed for this purpose.
Read the guide to emergency powerSources