Uninterruptible Power Supply (UPS) systems are still fundamental to data centre design with their key role to sustain the power supply when the mains fail. The core of a UPS system is its batteries – in the present day there is greater concern for green technologies for data centres so choosing the right UPS battery configuration and general battery rack maintenance is important in improving power efficiency.

The correct battery configuration choice optimises the reliability of UPS, hence why it is imperative to ensure the needs of the user are met whilst not compromising on resilience levels. The serial string configuration is where identical battery blocks are wired end to end to form the UPS battery – both simple and cost efficient, but if one battery fails, the whole string is disabled.

The alternative to this is multiple, parallel battery strings which use a combination of two or more serial strings – all strings having the same number of blocks. This is more resilient and provides longer battery autonomy during a mains outage.

Lead-acid batteries are the popular choice for many UPS systems, as standard UPSs use Open-Vented or Valve Regulated Lead Acid (VRLA) battery types. VRLA are favoured because they are more environmentally friendly and are low maintenance.

Battery maintenance is a vital part to keeping a UPS system running correctly, this entails checking the batteries for corrosion, leaks and cracks and tightening connections. A qualified individual from a UPS supplier will be able to do this and identify any problems which could result in replacing the batteries or temporary UPS hiring .