German battery supplier Sax Power has developed a new lithium iron phosphate (LiFePO4) storage system for residential applications. The company said it launched the product after running tests with more than 1,000 storage systems used by more than 300 customers.

The battery does not require an inverter and can be plugged into a secured household socket. Its capacity is 5.8 kWh and its efficiency rate is 99%, said the manufacturer.

Up to three of the battery packs can be installed in a household. End customers who are exempt from VAT can order the storage systems from German distributors and installers for €4,957 .

The new product includes a smart meter that is placed between the battery and the electricity meter. It communicates with the storage device via a LORA wireless connection or an RS485 cable connection and measures the amount of electricity the household uses in real time. This is how the smart meter regulates the delivery of electricity.

The core component of the storage is the digital control of the battery cells, which converts DC voltage directly into AC voltage, which makes the use of an inverter unnecessary.

The required household AC voltage is achieved by accumulating the cell voltages into a sinusoidal shape. The company said its patented circuit allows the cells to work independently of one another and optimally balance the state of charge within a storage unit or during subsequent expansion. The charge imbalance leads to a shortened lifespan for conventional home storage systems.

Sax Power said its product features cobalt-free lithium iron phosphate cells. In addition, the individual monitoring and switching of the battery cells enables the cells to be completely switched off and separated within 0.0002 seconds.

This mostly eliminates the risk of fire and explosion, the manufacturer said. After switching off, the entire system is below the safety voltage, which eliminates any risk for the installer and the customer during maintenance work.

by pv-magazine