Industrial batteries and how to manage their operation

A battery is a type of galvanic cell that converts chemical energy directly into electrical energy. The special features of batteries are their rechargeability and ability to store electrical energy.

This makes them an integral part of uninterruptible power systems - systems that maintain a constant power supply even in the event of a power outage or grid disturbance.

Despite their advantages and wide industrial applications, batteries are also a bit of a problem in the topic of uninterruptible power supply because they have limited capacity, life span and are sensitive to various operating conditions such as temperature, which can affect their premature loss of capacity or malfunction.

In order to increase the efficiency and protect the batteries from harsh operating conditions, so-called battery management systems are used. Rapid technological development of such systems affects the efficiency of battery operation, including the efficiency of electricity conversion, and allows to monitor the operation of galvanic cells in real time, in effect balancing the slow development of chemical power source technology.

TYPES OF INDUSTRIAL BATTERIES

The most common type of industrial cells are lead-acid versions. They provide great comfort of use, because they do not require maintenance of the electrolyte and can work in any position due to the lack of liquid electrolyte. The main representatives are sealed types SLA/VRLA, often called maintenance-free batteries. Thanks to sealed casings, they do not emit acid fumes and harmful gases during normal operation, so they are harmless to the environment and safe to use.

Maintenance-free SLA batteries are made with two technologies that differ in the way the electrolyte binds:

•    AGM batteries (Absorbed Glass Mat) – all of the electrolyte is absorbed by the highly porous glass fibers between the separators located between the lead plates of the battery.
•    Gel batteries – the electrolyte is a gel mass due to the addition of silica SiO2.

AGM batteries have a higher terminal voltage and are able to run longer due to their lower internal resistance than gel batteries. Additionally, they have a higher capacity because in gel batteries part of the electrolyte is a gelling agent.
On the other hand, gel batteries provide better cell cooling and greater resistance to vibration and shock. Further advantages are the ability to regenerate after hours of short circuits and resistance to surges.

AGM technology is most commonly used in UPS for cyclic operation, while the gel version is ideal for buffer power supplies.

Li-ion batteries are another type of battery that is increasingly finding its way into specialized and industrial applications. The operation of Li-Ion batteries is based on chemical transformations that occur as positive ions pass through the electrolyte between the cathode and anode. The cathode is made of lithium compounds, while the anode is usually made of carbon materials.

The characteristics of such batteries are:

• Large capacity in a relatively small size;
• No memory effect (can be recharged at any time);
• Low cell weight;
• Environmentally friendly (no heavy metals, recyclable);
• Long service life;
• High energy density;
• Operating in a high operating temperature range.

BATTERY MANAGEMENT SYSTEMS

Through constant emphasis on the use of new technologies that perform significantly better and have a longer life than their predecessors, Li-Ion batteries are slowly replacing older solutions where their use will positively impact the performance of the end device.

In order to get the most out of their batteries, while ensuring that they are protected from the environmental conditions in which they operate, most companies utilize additional systems that support the operation of such batteries.

BMS (Battery Management Systems)

BMS are electronic control systems that monitor and regulate the charging and discharging of batteries. Characteristics monitored most commonly include detection of battery type, voltage, temperature, capacity, state of charge, power consumption, remaining run time, charge cycles, and more.

Battery management systems are designed to ensure that the remaining energy in the cells is optimally utilized. To increase battery life, BMS protects batteries from deep discharge and from surges that can result from fast charging and high discharge current. If you have multi-cell batteries, the BMS also provides a cell balancing function so that each cell in the battery has the same charging and discharging requirements.

There are many types of BMS systems available on the market. Battery management systems are best selected with the help of a specialist who, after determining the requirements that the BMS should meet, will be able to propose specific solutions.