How do I correctly connect the Marstek B2500? Connection diagram explained

The Marstek B2500 is a plug-and-play solar storage system for balcony power plants with 2.24 kWh capacity and up to 1,600 W PV input. It significantly increases self-consumption and is easy to expand. This wiring diagram shows you how to connect it correctly.

Current Challenges in the Solar Industry

The installed capacity of balcony power plants is growing rapidly, but many users do not install a storage system – as a result, a large part of the energy generated during the day goes unused into the grid at night. A storage system like the Marstek B2500 makes the electricity generated during the day usable in the evening. Note: There is no feed-in tariff for balcony power plants – the advantage comes from self-consumption.

Why do traditional solutions fail in everyday life?

Traditional storage systems often require electricians and permits, are heavy, and don't fit on balconies. The Marstek B2500 is lighter at around 22 kg and can be installed in minutes. LiFePO4 cells achieve 6,000 cycles instead of a few hundred with old lead-acid batteries.

What makes the Marstek B2500 a practical solution?

The B2500 features dual MPPT trackers (1,600 W PV input, 800 W output), is compatible with most MC4 inverters, is IP65 protected, and can be controlled via an app (Bluetooth/WLAN). It is modularly expandable to multiple units.

Marstek B2500 Comparison

How do I connect the Marstek B2500 correctly?

Connect solar modules to PV-IN (MC4), observing the permissible current per tracker. Connect OUT to the inverter input. Press the power button, pair via app, and update firmware. If necessary, add more units in parallel. We carry suitable cables in our assortment.

Who benefits from the B2500 – typical scenarios

Tenants with south-facing balcony: without storage, a lot of unused surplus; with storage, significantly higher self-consumption – completely without drilling.

Family with base load (refrigerator, router): the stored solar power covers evening consumption and reduces grid draw.

Garden shed with multiple modules: the dual MPPT processes fluctuating production; modularly expandable.

Actual savings depend on consumption, orientation, and electricity price.

What questions do users have about the connection plan?

How many modules can be connected to the B2500?
Up to 4 modules in parallel, limited by the permissible input voltage/power.

What happens in case of overvoltage?
Automatic shutdown protects the system.

Can I expand the B2500?
Yes, modularly by adding several units.

Do I need an electrician?
Not for a ready-to-plug-in system up to 800 W; connection via MC4 and Schuko.

Is the app compatible with iOS?
Yes, via Bluetooth and 2.4 GHz WLAN.

Sources

• Federal Network Agency – PV Statistics
• Fraunhofer ISE – Solar Forecast
• DRBO Greenenergy – Balcony Power Plants

As of: 2026. Information may change. Brand and product names belong to their respective manufacturers.