What is a plug-in home battery?
A plug-in home battery, also known as a plug-in home storage system, is a compact battery system that you connect yourself to a standard electrical outlet. No installer is needed: you set up the device, connect it (often via an app or a P1 meter) to your energy usage, and the battery automatically starts storing and feeding back power.
The way it works is similar to a large power bank for your home. During the day, when your solar panels generate more power than you use, the battery stores that excess. As soon as the sun goes down or your electricity usage peaks, the battery releases that power back into your home. This way, you’ll need to purchase less electricity during times when it’s more expensive.
Comparing Plug-in Home Batteries: What Should You Look For?
When comparing plug-in home batteries, there are a few specific criteria to consider. After all, a higher capacity or a more attractive design doesn’t mean much if the system doesn’t fit your situation.
Capacity (kWh)
This determines how much electricity you can store. An average household consumes about 10 kWh per day. A battery with a capacity of 1.5 to 2 kWh therefore covers only a small portion of that. A rule of thumb: allow for 1 to 1.5 kWh of battery capacity per kWp of solar panels.
Charging and Discharging Capacity (watts)
This capacity determines which devices you can power directly from the battery. 800 watts is sufficient for lighting, a refrigerator, a router, and the TV, but not enough for a washing machine or an induction cooktop.
Cell chemistry
Preferably choose a system with LiFePO4 (lithium iron phosphate) cells. This chemistry is more stable and less flammable than standard lithium-ion and often lasts up to 6,000 charge cycles.
Expandability
Some systems allow you to expand them later with additional battery modules without having to replace the main unit. This is useful if you expect your energy needs to grow.
Emergency Power
Not every plug-in battery system continues to operate during a power outage. If you want your refrigerator or router to keep running during an outage, check whether the system has an off-grid connection with an emergency power function.
Still unsure which brand or model to choose? Our specialists are happy to help you find the solution that best fits your roof, energy usage, and budget.
Requirements and Options
Before you buy a plug-in home battery, it’s a good idea to consider a few things.
- Your solar panels. How much energy do you generate on average? And how much of that do you already use directly? This determines how much surplus energy you can actually store.
- Your outlet and circuit. Check whether you have a dedicated 16A circuit or if you’re connected to a shared circuit. That determines the maximum power you’re allowed to feed back into the grid.
- Your energy contract. With a dynamic contract, you can charge the battery during off-peak hours and discharge it during peak hours, which shortens the payback period.
- Your expected growth. Do you plan to install more solar panels or buy an electric car in the future? If so, choose a system that can be expanded.
The Pros and Cons of Plug-in Home Batteries
| Advantages | Disadvantages |
| Higher self-consumption of solar power. With a battery, this increases from 30% to 60% to 80%. | Limited capacity. Most systems store 1.5 to 6 kWh per unit. |
| No installer required. You install the system yourself, which saves time and money. | Power limitations; for high-power appliances such as a washing machine or cooktop, the system quickly falls short. |
| Because you need to purchase less electricity during peak-rate periods, your annual energy costs decrease. | Efficiency loss. Typically, 10 to 20 percent of the energy is lost during charging and discharging. |
| Prepared for the end of net metering. Starting in 2027, you will no longer receive full compensation for electricity fed back into the grid. | Less capacity than a fixed system. A fixed 10 kWh home battery offers significantly more storage. |
| An accessible first step. For those who want to experience how energy storage works without a major investment. |