Today electricity has become a necessity. All most all of our day to day works requires electricity. We need electricity for laptops, washing machines, electric cookers, Mobile phones, Coolers, etc. The best way to comprehend the difference between ups and an inverter is by first understanding how they work.

What is UPS (Uninterruptable Power Supply)?

UPS is a device that supplies energy to load in case of a power failure, like an inverter. A low capacity single phase online UPS with a capacity upto 1.5 KVA has an inbuilt battery of about 5 Ah to 10 Ah, which provides 15-30 minutes of power backup during a power outage. High capacity systems have batteries external to the UPS, but functioning depends on UPS type. UPS are primarily of 3 variants basis their working:

  1. Online UPS

Online UPS is a UPS type that supplies power to the AC load in normal operation and uses an inverter to provide AC power during a power failure. In Online UPS, the output power supply always stays ON i.e. the UPS keeps charging the battery and draws current from the battery to supply the load.

Hence, there is no switching and, therefore, no time delay in switching between its sources. There is no disruption in the case of a power failure, even for a nanosecond. In case of a power failure, the UPS stops charging the battery but keeps driving a load from the inverter battery.

Related Online UPS Products

2. Offline UPS / Standby UPS

Offline UPS or Standby UPS is a type of UPS that directly supplies power to the AC load from AC mains in normal operation and uses an inverter to power the AC load from the DC battery.

Since there are two separate supplies, the output supply must be switched between the two sources. The switching time of an offline UPS varies from 6 ms to 10 ms, sufficient to run computers and other sensitive appliances at home but not suited for banks or hospitals, as explained earlier.

During mains OFF condition, the battery stops charging, and the relay or static switch transfers the output line to the inverter side very quickly.

You can choose Prostar Offline UPS

3. Line Interactive UPS

Line interactive UPS draws its features both from Online and Offline UPS. For line interactive UPS, the inverter is part of the output. While the AC input is usual, the inverter will work in reverse to charge the battery and turn to battery power when the input fails.

The switching time is lower than Offline UPS and is generally around 5 ms. Internal components provide filtering and voltage regulation. A wide variety of input voltage variations is provided by line-interactive UPS systems before switching to battery backup. In areas where outages are uncommon, this technology is especially successful, but power fluctuations are normal.

Choose the line interactive ups for your use

What is Inverter?

Inverter is power electronic devices. The main purpose of these device is to convert DC to AC. In inverters, AC power supply is taken from AC mains and converted into DC by a rectifier.

These home inverters are available in various voltages and load capacities.

Another point to note is that an inverter works inversely to convert the AC supply into DC current during mains ON, which helps charge the battery.

Also, during Mains Power Off, it takes about 10-20 ms for inverter relays to switch over from mains power to battery supplied power.

Maybe you like the inverter

Key Difference Between ups and an inverter

Use Case & Backup Time

If you don’t have power cuts often, you can use a UPS to safeguard your computer from any major hardware failure. The switch to UPS is almost instant, and this doesn’t shut down your computer. UPS typically offers a backup of around 30 minutes or so.

The switching of UPS from the mains supply to the battery is immediate, whereas the Inverter takes more than UPS. For computers, the switching time of inverter is more than it can handle, and it will usually reboot due to the interrupted supply.

UPS can provide backup for your devices for around 15 minutes, whereas an Inverter can provide backup for hours depending on its capacity. The inverter allows you to power the complete house depending on the capacity.

Use for Application

You need to consider your requirements after knowing all the difference between ups and an inverter, and then choose. An office with a lot of computers and communication equipment, for instance, typically requires an Offline or line-interactive UPS power.

On the other side, a bank or a hospital may require an Online UPS. A home that uses only ventilation and lighting may use an inverter, which provides an extended power backup for hours. You can decide the best configuration possible with a professional evaluation of your house.

Working Mode

The UPS is AC INPUT to DC, DC to AC OUTPUT; and the inverter is DC INPUT to AC OUTPUT.


UPS units are more costly, it does not make sense to size them with no power supply for hours of operation.


The UPS provides the electric backup to the appliances without delay and fluctuation. And, the inverter is a medium between the primary power supply and the battery. The battery helps in storing the energy and during the power outages convert the store AC into DC and provides power to the electrical inverter.

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