Understanding the Battery Inverter: A Comprehensive Overview

A single-phase battery inverter is only suitable for small PV systems in a single-family home. This variant is only permitted for PV systems with up to 4.6 kilovolt-ampere (kVA). 3-phase battery inverters are mandatory for larger systems over 4.6 kVA. If you'd like to use an inverter with battery for grid feed-in or with a battery-backup function, a three-phase battery inverter from SMA is the ideal choice. This ensures that the energy is fed evenly into the grid and all loads can be reliably supplied with electricity when providing backup power to your own household or company.

There is no general answer to this question; the basic rule is: the larger the PV system is, the more powerful the inverters and the associated storage systems should be. For example, for a high-capacity setup a battery inverter 3000W is needed. The SMA Home Storage can be configured for capacities of 3.2 kWh to 16.4 kWh and offers the right solution for all three variants.

Overall, PV inverters and battery inverters work in combination in a PV system. This ensures that solar energy is used efficiently, the batteries are charged and the building's and utility grid's energy needs are met.

• The PV inverter converts the direct current into alternating current, feeds the surplus energy into the grid and takes care of optimizing the energy: this is also possible without a battery inverter.

• A battery inverter by itself can only convert direct current from an electricity storage system into the required alternating current, thus it can only function combined with a PV inverter.

Various factors influence which battery inverter or battery and inverter combo fits which PV system – these include the size and performance of the PV system and the capacity of the battery storage system, and possibly specific requirements such as the need for a 12V battery inverter. But it's not just compatibility that plays a role, other features also affect the selection. Additional functions such as an integrated energy management are to be considered as well as an energy yield as high as possible. Our trained Solar power professionals as well as the SMA Planning Tool Sunny Design will help you with planning.

Most manufacturers of battery storage systems allow cable lengths of a maximum of 5 to 10 meters between the storage unit and the battery inverter. Each battery manufacturer indicates the exact requirements in the product documentation. The cross-section is also to be taken into account in addition to the cable length. If the cable route includes outside areas, it is also important to ensure that there is UV-resistant insulation. In general, the battery storage systems as well as the PV and battery inverters generate heat during operation. Therefore, take note of the maximum ambient temperature specified in the product documentation. For this reason, the components should be as close to each other as possible, but the distance should be large enough to allow the heat to dissipate.