Most faults in UPS systems are caused by defective UPS batteries. One could say that the vulnerability of UPS systems is focused on battery damage. This can be avoided by the proper procedures and ways of using the UPS batteries. We will briefly analyze the five main causes of premature battery damage and how we can prevent them.
We all know that batteries store power, generated by a chemical reaction inside the UPS batteries. Generally, the life of standard batteries using VRLA-Valve-Regulated Lead-Acid technology is 3-5 years. However, there are a number of environmental, chemical and other user-related data that can significantly affect the life of the batteries. The following are serious mistakes to be avoided in order to ensure the maximum possible life of our UPS batteries.
Factors that affect and cause premature damage to accumulators
Nothing can be done to prevent a battery from weakening when it reaches the end of the period of use for which it was designed.
Inappropriate battery storage conditions
- Stored batteries, even when not in use, wear out, resulting in a reduction in useful life.
- Because this type is discharged, it loses its energy in small quantities on its own.
- To ensure maximum durability, batteries must be recharged every 2-3 months of storage. If they are not recharged, they are likely to lose significant amounts of energy even after just 6 months.
- The lifetime given by the manufacturer can be ensured by storing the batteries at low temperatures of the order of 10 Co.
High environmental temperature
- The capacity or energy a battery can offer is given at 25 ° C operating temperature.
- Any variation directly affects battery performance and battery life.
- As a general rule, for every 10 degrees of increase in environmental use temperature, battery life is reduced by 50%.
- This requires the use of the battery / UPS in a properly cooled room, as well as frequent control, to determine the temperature generated in the UPS system during operation.
- Checks should be carried out on cooling fans, for example, and on ventilation openings.
- In the event of a power failure, the UPS provides power to the load using its built-in batteries.
- When the power comes back, the batteries are recharged for future use.
- One discharge and recharging is characterized as a Discharge Cycle.
- When a preinstalled battery contains 100% of the energy specified in the specifications.
- However, discharging and recharging the battery reduces the amount of energy it stores.
- Standard commercially available batteries offer around 300-400 discharge and recharge cycles, up to 80% of the battery capacity.
- There are special batteries for photovoltaic applications for example that offer more than 1000 cycles but with significantly higher costs.
Inappropriate charging voltage
- A regular 12V battery consists of 6 cells of 2V.
- A lower recharging voltage than specified may cause crystals on the lead plates used in the batteries.
- These crystals will solidify and reduce the capacity and energy a battery can deliver.
- Excessive charging voltage can cause large quantities of gases, hydrogen, and oxygen, causing fluid to drain into the batteries.
- This can cause excessive temperature rise, causing the so-called “thermal runaway” to result in direct damage or even worse fire and explosion.
Inappropriate battery application
- This type of battery is specifically designed for use with UPS Systems.
- Like other types of batteries designed and built for other devices.
- UPS batteries are built to deliver large amounts of energy in a short period of time, so UPS usually offers 10-20 minutes of autonomy.
- Other types of batteries, for example, used in telecommunications, are designed to offer small amounts of energy for long periods of time.
- Usually between 4-8 hours. If a user, using batteries built for a UPS System in telecommunication applications, will force the battery to work for longer periods than the one for which it was designed.
- This will lead to overheating in the lead plates and irreparable damage.
- It is a fact that we do not use car batteries in UPS systems or telecommunication applications.
- The technology used is completely different and unsuitable for such use.
- UPS systems usually use a large number of batteries in order to generate a high current that is fed into the AC inverter of the UPS.
- If a battery in this battery series “opens”, there will be no power on the UPS, which will be deactivated.