Yes. The entire 500 series is designed so that function and performance upgrades are possible digitally at any time, without replacing any hardware. The 500 Lite can simply be upgraded to a 500 (5 kWh) via a paid in-app purchase. Unlocking the additional 2 kWh of storage capacity costs €399. A subsequent upgrade to the 500 PRO is also possible. Because different legal requirements apply to the higher output, the upgrade from 500 to 500 PRO must be carried out by a certified installer listed in your grid operator's installer directory.

In practice, the MPPT input power is sufficient even for high-power solar modules such as 500 Wp panels. With two active MPPT channels, each provides up to 800 W; with four active channels, each provides up to 625 W.

Clipping losses in Germany occur for approximately 200–300 hours per year under optimal south-facing conditions, resulting in an estimated loss of approx. €34–51 annually at full load. However, the benefits of overpaneling, especially under low-light conditions, during morning/evening hours, and in partial shading, generally outweigh these losses in most scenarios.

Yes. The SunEnergyXT 500 series storage systems deliver up to 2,400 W of total output power. For example, if 800 W is being fed into the home grid, up to 1,600 W remains available via the integrated backup socket, without any manual switching or special mode being required.

The backup socket is always active when in use. If the battery is depleted, the system automatically switches to grid power. This allows the 500 Lite to function simultaneously as a home energy storage system with backup power supply.

The maximum charging power of the SunEnergyXT 500 Lite is 2,400 W, regardless of the source. Solar (PV) and grid charging (AC coupling) can be used simultaneously. However, the total input power cannot exceed 2,400 W.

Example: If the PV system generates 2,000 W, up to an additional 400 W may be supplied via AC charging.

500 Lite and basic version (800 VA): Complies with VDE-AR-N 4105:2026-3 for simplified registration by non-professionals with the grid operator. Requirement: connection via an energy socket (e.g. Wieland socket). A standard earth-connected plug (Schuko in German) is not compliant. If no energy socket is installed, a certified electrician is required.

PRO version (2,400 W): Installation and registration by a certified electrician is required. Exempt from §14a EnWG: since each head unit can be controlled independently, the grid connection power of the individual head units is not added up. Therefore §14a EnWG (controllability by the grid operator) does not apply. See the official statement of the Federal Network Agency: https://www.bundesnetzagentur.de/DE/Vportal/Energie/SteuerbareVBE/artikel.html#FAQ1088672

A smart meter gateway (iMSys) is only required for larger system expansions. Registration with the market master data register (for the German market) is always required.

The entire 500 series offers a local API (via HTTP) and full Home Assistant integration for maximum flexibility. Additionally, the following energy meters are natively supported: Shelly (Pro) 3EM und EM-50, EcoTracker IR und P1 sowie bitShake.

Thanks to the open API, integrations into existing smart home environments is straightforward.

The SunEnergyXT 500 Lite is designed for outdoor use:

Protection class IP65 (dust-tight and water jet resistant)

Operating temperature: −20°C to +55°C

Integrated battery heating (automatic heating below 0°C)

Built-in fire suppression cartridge for added safety

Above 45°C, output power is automatically reduced to protect the LFP cells.

Recommendations: Install beneath a carport, canopy, or balcony roof to maximize service life.

Yes, on the software side: The SunEnergyXT 500, 500 Lite and 500 PRO can operate together with BK215/BK215 Plus storage units via a multi-zone strategy (cloud-based) or locally through Home Assistant. It is added to a separate "space". One energy meter (e.g. Shelly) is sufficient for both spaces.

However, physical connection is not supported: A direct cable or plug connection between the 500 Lite, 500 or 500 PRO and the BK215 (Plus) is not possible. Integration is handled exclusively via software.

Yes. The backup socket (emergency power) and UPS mode (switching time under 10 ms) are always operational, even without internet access. Off-grid operation with up to 2,400 W output per main battery unit is also independent of connection to the internet.

For full control via the SunEnergyXT app, a cloud connection is required. Alternatively, local control is available via local API or Home Assistant.

An internet connection is recommended for initial setup and required for firmware updates. Manual update options (e.g. via external devices) are currently under evaluation.

The 500 Lite features passive cell balancing.

The entire SunEnergyXT 500 series uses high-quality 314Ah EVE LFP (lithium iron phosphate) cells and comes with our 10-year manufacturer warranty with a capacity guarantee up to an energy throughput of 40,192 kWh. Since the 500 Lite cycles 3 kWh per charge cycle, this works out to more than 13,000 full cycles.

A full charge cycle corresponds to charging and discharging the usable capacity once. If the battery is fully charged and discharged once a day, that amounts to around 365 cycles per year. Based on this calculation, our battery could be operated for up to 35 years, while calendar ageing (chemical side reactions in the cells that progress over time and especially at higher temperatures) continues in parallel. Either way: you can always rely on our 10-year warranty.

Conditions: warranty booklet or www.sunenergyxt.com/garantie