How Long Will 12v Battery Last with Inverter?

How Long Will 12v Battery Last with Inverter? [Guide]

An inverter which is also known as a power inverter or solar inverter is an essential unit in a solar power system. It is the device that converts DC to AC. How long will 12v battery last with the inverter. If you have this question in selecting the right inverter for your house’s solar panel system, do continue reading! In this article, we are going to answer your question with brief explanations. 

The generated electricity in a solar panel is stored in a battery as a DC current. As all the household appliances like lights, kitchen appliances, and microwaves are made to work with AC current, the necessity for an inverter arises. There are three types of inverters available for household usage.

Those are, namely, string inverters, microinverters, and string inverters with power optimizers. 1000-watt inverters are the widely used type, and these can be used with a car battery to get an AC current to your car. The inverter’s history goes back to the 19th century, and the first used ones were mechanical.

How Long Will 12v Battery Last with Inverter?

Today a solar system in a house with an inverter will not only supply AC power to your household requirements but is also capable of monitoring and acting as a communicator port for the computer networks. Using an inverter is a low-budget arrangement to produce usable electricity.

How long will 12v battery last with the inverter? This question must be answered with references to three things, namely,

  • Type of the inverter battery- A battery’s usable capacity differs from the manufacturing technology. Usually, in a 100 Ah battery, only 15% could be used in the inverter without creating damage.
  • Size of the battery in ampere-hours (Ah or amp hours) – Amount of current produced within 1 hour.
  • AC load in watts

The average efficiency of an inverter has been calculated as around 85%-95%. But some brands manufacture inverters with 97% -99% efficiency. If the efficiency is higher, the power loss becomes low. There are inverters even with a higher load, like 4000w. When connecting an inverter to a battery, you should make sure that the battery’s voltage tallies with the input voltage of the inverter you use. 

How Long will 12v Battery Last with 1000w Inverter?

12v batteries are usually a 100Ah of amperage. In order to calculate the total time a battery would last, you need to find the amperes per hour value. The equation is as follows. 

Amperes Per Hour = AC Load in Watts/ Voltage of the Battery /Inverter Efficiency

If you have taken an inverter that has an 800-watt load with an 85% efficiency for the 12v battery, then according to the above equation, you will get the lasting time as 1 hour and 10 minutes. 

Amperes Per Hour= 800w /12v/ 85% = 78 Ah

This means that an inverter with 800wat outputs 78 amperes of current in an hour. The battery is capable of giving 100 amperes per hour, and the inverter is capable of making 78 amperes per hour. Therefore, it will take approximately 1 hour and 10 minutes to get the total charge converted by this inverter. 

How Long will 12v Battery Last with 1000w Inverter?

How Long Will 12v Battery Last with 250w Inverter with 95% Efficiency?

Amperes Per Hour= 250w/12v/95% = 22Ah

This shows that here the inverter can give 22 amperes of AC current in an hour. When the battery gives 100 Ah, it will take approximately 4 -5 hours to convert the total DC stored in the battery. 

What Should You Consider When Converting Current from a 12v Battery by Using an Inverter?

  • There is a recommended discharge efficiency for a battery, do not use an inverter with a lower efficiency than that because it will gradually cause issues in the converting process.
  • Whether it is the battery or the inverter, make sure you arrange not to overload those. It is safe to use 1000 watts for the inverter in most cases. When you use the inverters according to the instructions given along with the battery’s manual, there will be no damage, and if there is a malfunction, you can get the assurance of your warranty. 
  • Considering the surge watt value is also a must. Surge watts are the watts needed when starting the appliances. Sometimes surge value maybe two times the working watt value. Your inverter must be able to give this value.
  • You must read the manual you get along with the inverter when purchasing to identify how many batteries can be connected to it. In general, it is recommended not to connect a current that is larger than 12 times the capacity of an inverter. 
  • As we have discussed earlier, you must select an inverter with a voltage that matches the voltage of the battery where the charge is stored. 
  • Be aware of the poor-quality brands and purchase an inverter from a reputed brand with warranties.
  • To avoid your battery becoming zero, switch off the inverter when you do not use the current for any activity. But you also should care about the self-discharge of batteries to prevent energy loss.

Is it Safe to Keep Inverter and Battery in Bedrooms?

An inverter and a battery are things to be avoided in your bedrooms. The inverters may produce high heat and sometimes expel harmful gases in the cases of charging and discharging. If you need to use an inverter for a long time, you should place the inverter and the battery in a place with proper ventilation. 

You should keep the inverter in a dry place and make sure the place does not get direct sunlight too. 

What Size Inverter Do I Need to Run a Fridge?

The surge watt requirement of a fridge is basically three times the running watts. Therefore, you will probably need an inverter that can give a surge power of around 1800 watts for a few seconds with a constant output of about 600 watts. 


If you are concerned about the conversion of DC and the time taken for it by an inverter, this article will give you the answer to your question.

Check Out This Video,

VIDEO CREDITS: Zim Inverter YouTube Channel

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