Skip to main content

Battery backup systems for superior use and reliability


Battery backup systems are essential to keep basic operations running in the event of a power outage.

Facilities such as data centers, hospitals, public companies, airports, oil and gas facilities, and railways cannot function without 100% backup power reliability. Even standard commercial and manufacturing facilities have backup power systems for their emergency systems, alarms and controls, emergency lighting, and smoke and fire control systems.

battery backup systems

Most standby power systems use an uninterruptible power supply (UPS) and a set of batteries. The UPS serves as a means of backup to the Digital Control System (DCS) in order to maintain control of the plant operations until it can safely shut down or until the standby generator starts.

Although most of the batteries used in modern UPS systems are maintenance free, they are still prone from corrosion, internal shorts, sulfation, drying, and seal failure. This article establishes the recommended practices in order to maintain the optimal operation of the "battery banks", so that the reserve will be ready in the event of blackout.

The two main indicators of battery status

One: internal resistance of battery

Internal resistance is a test of service life, not capacity. The resistance of the battery remains considerably uniform until it approaches the end of its useful life. At that point the internal resistance increases and the battery capacity decreases. Measuring and recording this value helps to identify when the battery should be replaced.

Use only a special battery tester designed to measure the resistance of the battery while it is in use. Read the voltage drop across the load current (conductance) or AC impedance. Both results are expressed in ohmic values.

An isolated ohmic measurement has little value without context. Recommended practice requires the measurement of ohmic values over months and years. Each measurement must be compared to previous recorded values to generate a baseline.

Two: the discharge test

The discharge test is the best way to find out the actual available capacity of a battery, but it can be difficult to carry out. During this test, the battery is connected to a load and discharges over a specified period of time. In addition, the current is regulated and a constant known current is established while the voltage is measured periodically. Details of discharge current, specified period of time for discharge test, and battery capacity in amp-hours can be calculated and compared to manufacturer's specifications. For example, a 12 V 100 Ah battery may require a discharge current of 12 A for eight hours. A 12V battery is considered discharged when the terminal voltage is 10.5V.

battery systems

Batteries cannot withstand critical loads during a discharge test, or immediately after completion. Transfer critical loads to another battery bank until considerable time elapses after testing is complete, and reconnect a temporary load, comparable in size, to the tested batteries. Also, before testing, prepare a cooling system to compensate for the rise in ambient temperature. When large batteries discharge, they emit a large amount of energy in the form of heat.

Good batteries should maintain a capacity greater than 90% of the factory ratings. Most manufacturers recommend replacing the battery if its capacity drops below 80%. When performing battery tests, look for the following fault indicators:

  • More than 10% drop in capacity compared to baseline or previous measurements
  • 20% minimum increase in impedance compared to reference or previous measurements
  • Continuous high temperatures compared to manufacturer's reference and specifications
  • Degradation in the condition of the plates

How to perform standard battery tests

Float voltage

  • Isolate the batteries from the charging and charging system.
  • Measure the individual cell or string voltage monthly with a digital multimeter or battery analyzer.

Charger outlet

  1. Measure the output voltage at the charger's output terminals monthly with a digital multimeter or battery analyzer, such as the BT500 series.
  2. Observe the output current displayed on the charger's current meter or use a clamp meter. Take the measurement monthly.

DC float current

  1. Consult manufacturer's specifications for approximate and expected values of float currents.
  2. Use an appropriate DC clamp meter to measure the expected float current once a month.

Internal ohmic values

  1. Use a battery analyzer, such as the Fluke 500 series, to measure individual battery ohmic values on a quarterly basis.
  2. Set the baseline values and enter them into the battery database.

battery solutions

Top 5 causes of battery failure

  1. Loose terminal and intercell connections
  2. Aging
  3. Overcharge and over discharge
  4. Thermal leak
  5. Undulation

Weakest link

When a battery fails within a chain, the entire chain

  • is out of service
  • reduces service life ²

The worst case

A battery with a high impedance level can overheat and catch fire or explode during discharge. Measurement of voltage alone will not indicate this risk.

¹ The main cause of batteries failure is heat. For every increase in average temperature of 8 ° C (15 ° F), the battery life decreases by half.

² A bad battery increases the charging voltage of adjacent batteries due to the configuration of the charger, which affects the life of the entire chain.

Common Battery Terms

  • Capacity test: discharging a battery at a constant current or supply, at a given voltage.
  • Floating current: current that flows while the battery is held at float voltage.
  • Internal ohmic values: internal resistance of the battery (characteristic of each battery).
  • Download test: the battery is connected to a load until its voltage drops below a defined and pre-set limit.
  • AC ripple current: Residual AC in rectified voltage in DC discharge and inverted circuits.


Popular posts from this blog

What is better ducted or split air conditioning?

 Have you decided to install air conditioning in your home or workplace? When summer approaches and temperatures begin to rise, we realize the need for a quality air conditioning installation, which allows us to enjoy our home as comfortably as possible. The best brands of air conditioning, such as Mitsubishi Electric , sell different types of air conditioning devices, such as split or ducted air conditioners . Deciding which one is the best depends on knowing its characteristics, advantages and disadvantages. Ducted air conditioning It is a system that centralizes the distribution of air through a false ceiling throughout the house. Ideally, the ducted air conditioner has programmable louvers that regulate the air flow. This air conditioning installation allows the house to be zoned , that is, to regulate the amount of air and the temperature of each room in the house or area of ​​a workplace. In fact, each room has its own thermostat, which regulates the opening of the grill accord


The story of the prefabricated diamond begins in the mid-20th century, but in jewelry use, it is only now beginning to raise its profile. Prefabricated or synthetic diamonds have many nicknames, the most common of which are Lab Grown Diamond and Man Made Diamond. At Argyle pink diamonds , we call the synthetic diamonds in our own collection Argyle pink diamonds Man Made diamonds.Pictured is Argyle pink diamonds Man Made pink diamond. It has a carat weight of 0.343 ct and a price of 392 euros. A similar natural diamond would cost about 24,000 euros. What are Argyle  pink diamonds  Man Made diamonds? They are diamonds. They are diamonds in the same way that Koh-i-Noor, who rests in the crown of the Queen of Britain, is a diamond. Does anything distinguish synthetic diamonds from those found in nature? Yes to distinguish, a very strong distinguisher is the origin of the diamond. Argyle pink diamonds Man Made diamonds have not been dug from the ground, but have been made in the factory. Wh


The most common way to process a wooden floor before applying a varnish is to sand it.  It is needed mainly when we want to give it a new image or completely renew it.  Before we start work, however, make sure that the floor is completely hardened and bonded with glue, and then prepare the appropriate tools that will bring the desired effect. What do we polish? Modern belt sanders are used for sanding wooden floor sanding .   Such machines have an endless sanding belt system that rotates on the sanding and guide shaft.  This solution has many advantages, including extended life of the belt, which does not heat up at high temperatures and is equipped with a self-cleaning system during grinding.  Modern belt grinders have built-in suction systems, we call it dust-free grinding technology, they also give great opportunities to adjust the sanding belt and roller pressure.  In turn, angle grinders are used to smooth edges, corners and hard-to-reach surfaces. IS IT POSSIBLE TO SANDING A WOOD