What is Difference between UPS & Inverter


  • We are heavily dependent upon appliances that run on electricity such as fans, lights, AC, fridge, Computer and so on.
  • Whenever there is a power cut, electricity supply to these appliances is cut off and they stop working. However, if we have backup supply devices such as UPS and inverter, we can ensure Power supply to appliances and not bothered with power cuts.
  • However, people remain confused with the difference between a UPS and an inverter because UPS and inverters both are providing back up power supplies during main power outage.
  • Inverters are preferred more for general electric appliances whose working does not get affected by extended delays in power supply.
  • UPS are used for electronics appliances such as computer, servers, workstations, Medical Equipment which perform critical task and cannot tolerate delays in power supply.
  • An off-line ups (the standard) switch to the batteries in 3 to 8 milliseconds, after the main power has been lost. While Inverter changes over in about 500 milliseconds.


  • UPS means uninterrupted power supply.
  • Uninterruptible power supply (UPS) provides uninterrupted power to the equipment. It means switching time from power cut to battery power is vey less hence important and critical equipment like computer, desktop .Medical Instruments is not switch off and we can lose data.
  • A UPS is a complete system that is consisting of many parts that include batteries, a charge controller, circuitry any transfer switch for switching between the mains and back-up battery, and an inverter. An inverter is needed because the battery can only store DC power and we need to convert that back to AC in order to match the appliances connected in the main power line.
  • UPS= Battery charger + Inverter
  • UPS is nothing but inverter with inbuilt battery charger.
  • UPS give backup only 10 to 20 minutes. The main intention of it is to provide backup only for small time so that you can save the programs and data.
  • UPS also gives protection against line abnormalities like Surge, Voltage fluctuation, Under Voltage, Over Voltage, Spike, Noise.


  • Inverter circuit simple converters battery DC current to AC and supply
  • In inverter inverts the direct current to an alternating current. During normal condition electrical supply is direct feed to the Load. It also takes the supply from the AC source and charges the battery.
  • During the power cut, the inverter receives the supply from the battery and convert it DC to AC Power and provides the power supply to the electrical equipment.
  • Inverters purpose is to provide power backup to total home appliances, lights, fans.
  • Inverter uses flat plate or tubular battery to store electricity. So it requires continuous maintenance, needs to fill the distilled water toppings at regular intervals of time.
  • Inverter does not give protection against line abnormalities

Difference between UPS and Inverter:


Comparison of  UPS and Inverter
Descriptions UPS Inverter
Definition UPS means Uninterruptable Power Supply. Inverter is a device which converts DC electricity to AC
Function It is an electric circuit (device) which instantly backs up power supply for a gadget. The gadgets works continues to work on smoothly and there is no damage to it.


Inverter consist circuitry which converts AC to DC and stores in the battery. When power supply goes off, that DC power is converted back to AC and is transmitted to the respective electronic gadget.
Principles It first converts AC to DC Power to charge the battery than Convert DC Power to AC Power (Inverter) and this AC power is supplied to Load. However, UPS monitors the input voltage level and processes it in terms of voltage regulations.

UPS= Battery charger + Inverter

Inverter converts DC power (stored in its battery) to AC Power supplied to the devices. Normally AC Power charges the battery .It uses relays and sensors to detect when to use DC power or AC Power, for DC power.
Back up Time Power Back up for Short Duration Power Back up for Long Duration
Types (a) Offline UPS, (b) Online UPS and (c) Line-interactive UPS.


(a) Square Wave, (b) Quasi Wave,

(c) Sine Wave

Main Part Rectifier/charger, Inverter ,controller Inverter and controller.
Switch over Time 3 to 8 milliseconds. 500 milliseconds.
Voltage Fluctuations While voltage fluctuations in input supply can be adjusted by the UPS, the output voltages are desired to be as smooth as possible.

In smoothing the voltage outputs, UPS are considered better as compared to inverter.


Inverter does not give protection against voltage fluctuations
Circuitry Sophistication UPS circuitry is far more sophisticated than that of inverter’s Inverter has Simple circuit then UPS
Pricing UPS more expensive than an inverter. Inverter is less expensive than UPS
Application UPS are used for electronics Application such as computer, servers, Network Switches, workstations, Medical Equipment, Processing Equipment which perform critical task and cannot tolerate delays in power supply. Inverters are preferred more for general electric Application which working does not affected by extended delays in power supply.
Protection UPS provide protection against voltage spikes, voltage drops, instability of the main frequency and harmonic distortions Inverter does not provide protection against Line abnormalities.
Battery Used sealed maintenance free (SMF) battery Used flat plate or tubular battery
Battery Maintenance Do not require any maintenance. Requires continuous maintenance, needs to fill the distilled water toppings at regular intervals of time
Energy Consumption More due to constant battery Charging Less


  • The UPS and inverter both provide the backup supply to the electrical system. Two major differences between the UPS and inverter are that
  • The switching of UPS from the main supply to the battery is very immediate so it is used to provide backup power of important or critical electronics equipment. whereas in inverter the switching from mains supply to battery takes times so it used to provide less important electrical equipment.
  • The UPS provide protection to the load against Spike, Voltage fluctuation, Noise while Inverter does not provide any protection to the load.

About Jignesh.Parmar
Jignesh Parmar has completed M.Tech (Power System Control), B.E(Electrical). He is member of Institution of Engineers (MIE) and CEng,India. Membership No:M-1473586.He has more than 16 years experience in Transmission -Distribution-Electrical Energy theft detection-Electrical Maintenance-Electrical Projects (Planning-Designing-Technical Review-coordination -Execution). He is Presently associate with one of the leading business group as a Deputy Manager at Ahmedabad,India. He has published numbers of Technical Articles in “Electrical Mirror”, “Electrical India”, “Lighting India”,”Smart Energy”, “Industrial Electrix”(Australian Power Publications) Magazines. He is Freelancer Programmer of Advance Excel and design useful Excel base Electrical Programs as per IS, NEC, IEC,IEEE codes. He is Technical Blogger and Familiar with English, Hindi, Gujarati, French languages. He wants to Share his experience & Knowledge and help technical enthusiasts to find suitable solutions and updating themselves on various Engineering Topics.

12 Responses to What is Difference between UPS & Inverter

  1. Prabhanshu says:

    Your article related UPS & Inverter is very important for me. Thanks for sharing your article.

  2. Habibur Rahman says:

    nice post. if it possible then please post about Electrical Home uses Gang switch and socket in details technical specification and Electrical FAN in details technical specification. mass details

  3. mohamad says:

    thanks for the nice subject

  4. Muhammad Awais Manzoor says:

    sir i confused in back e.m.f of generator and motors so plz give me a concept …thnxxx

  5. AUNG SOE says:

    thanks,we got lot of knowledge.

  6. subhashini M. reddy says:

    the article was very informative. thank you very much Jignesh sir. looking for more such articles sir.

  7. muhammed kabir isa says:

    A very comprehensive explanation and educative.

  8. Su Mon Myint says:

    Dear Sir!
    Could u explain me Current transformer saturation?

  9. Ajoy says:

    Nicely explained article, I have one query…Hope you will help,
    Presently we are having an online UPS of 6 KVA..
    Its battery bank consists of 20 numbers of 12V, 26 AH batteries..
    We have measured the load current on ups output , its 4 Amperes and at present it is giving us a backup time of approx 4 hours..
    Now..we want to increase the backup time of the UPS. My query is upto what battery size (in terms of AH hours) is suitable so that we can have a backup time for 8 hours?

  10. Gopal K says:

    I am a big fan of you and read your articles with great interest
    My comment: ups maintains frequency level within the prescribed band. For input frequency too,if it falls out of pre fixed range it will go to by pass mode.
    I once again highly appreciate your articles.
    Thank you.

  11. poonam says:

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  12. deepika says:

    It’s actually a great and helpful piece of information. I am satisfied that you simply shared this helpful info with us. Please stay us informed like this.
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