Two figures matter when choosing a battery, and they are often confused. The right choice starts with understanding the difference.

kW and kWh

• kW (power) shows how much load it can supply at one time.
• kWh (capacity) shows how long it can run that load.

You need both. With large capacity and low power, the system runs for a long time but cannot start a powerful device.

How many kWh do you need?

A simple calculation: load (kW) × time (hours) ÷ 0.9. Here 0.9 is the 90% depth of discharge recommended for LiFePO4 batteries, meaning not all of the capacity is counted.

Example: you want to run a 1.5 kW load for 6 hours during a power cut. 1.5 × 6 = 9 kWh, and 9 ÷ 0.9 = 10 kWh. Two 5.2 kWh modules (10.4 kWh) meet this need.

You can see an estimated capacity for your monthly use in the solar system calculator.

Which solution suits which site

Solution	Key figures	Where it is used
Xupernova 51.2V 102Ah module	5.2 kWh, LiFePO4, up to 16 in parallel (83.2 kWh)	Homes and small sites
Xupernova outdoor cabinet	50 kW / 100 kWh, hybrid inverter and EMS included, expands up to 10 cabinets	Business and industry
Wolun ECO-E10FT1044LP-2	500 kW / 1044 kWh, liquid cooling, microgrid mode	Large industry and microgrids
Xupernova mobile station	500 kW / 1032 kWh, 20 ft container	Emergency power, mining

You can see all products in the energy storage section.

What to check before buying

• Inverter compatibility: the battery voltage must suit the inverter. 51.2 V modules work with a 48 V inverter.
• Installation location: the battery should be kept in a place and temperature that meet the manufacturer's requirements.
• Expansion: if demand may grow, check whether modules can be added later.
• Safety: connection work should be done by a qualified specialist.

Conclusion

First decide which load must run and for how many hours; the capacity follows from that. Send us your list of loads and the backup time you need, and we will calculate a suitable system together.