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This is How Intex Tests a Smartphone Battery For Reliability

Along with the advancement in the mobile technologies, 21st century witnessed the rise of the Li-ion battery technology which was a revolution in itself. Since these batteries had long life, they could be recharged and discharged time and again at minimal operational cost. Lithium has the highest electrochemical potential which gives it the capacity to deliver the highest voltage upon reaction. Unlike, the previous battery technologies, these batteries have higher storage capacities and are a lot less toxic and cheaper.

Last decade, technology space witness many groundbreaking developments ranging from Li-polymer batteries which could handle very high capacities with the same size, the pouch cells which light weight and the latest were being rapid charging technology. Extensive research in the field of batteries has enabled longer hours of gaming, longer internet usage and longer talk time.

“Battery is a wild animal and artificial intelligence domesticates it.” became the anecdote of the mobile phone manufacturing industry as these batteries needed protection circuit boards (PCBs) for control. This industry is still looking forward to a breakthrough which will further reduce the size of the battery but would disruptively increase its capacity but until that day 4000 mAh is the limit within which all battery manufacturing companies have to work.

This year, over 35 mobile manufacturers are competing against each other to maximize their market share in India. The brands need to get the pulse of today’s consumer to be able to claim the desired market share. One of the primary drivers for brand loyalty in Indian consumer is the battery backup. High battery capacity but low weight is one of the major attractions for a consumer. Safety of the consumer becomes the main concern for the manufacturers when such high-energy densities are delivered in small spaces. Multiple tests must be carried out to ensure safety of consumers.

Recently, INTEX, installed a highly sophisticated, soon to be BIS accredited, Battery Reliability & Safety Laboratory in one of the manufacturing units in NOIDA. This lab is motivated to fulfill the requirements of the UN 38.3 safety standards. INTEX is the first organization to install such a lab setup in India and with this lab it has raised the bar for industrial standards to support customer safety, for other mobile phone manufacturers.

There are 8 tests which comprise the UN 38.3 safety standards. The batteries are selected on a random basis from the battery lot under quality assurance examination. The 8 tests which are carried out are:

1) Altitude test: As the altitude from the sea level rises the air pressure decreases which could have a detrimental effect on the batteries. This test allows us to segregate the subpar batteries. In this test, we set the chamber pressure to only 12% of the atmospheric pressure. The test is carried out for a period of 6 hours. The observation period is 24 hours after which the battery is checked for leakages, swelling or fire. If the battery passes the test then the next stage test is carried out.

2) Thermal shock test: The current generation has many gaming enthusiasts who have a passion for high end games. These games are not only demanding on the mobile phone but also on the batteries which get discharged with a heavier load. This causes the battery to get heated up too. Also, a portion of our customer base faces extreme climatic condition where the temperature is subzero. This test simulates both these conditions in their respective extremities.


In this test, the battery is kept at a temperature of 75⁰C for a period of 6 hours. Subsequently, the chamber temperature is rapidly changed -40⁰C. The battery is again kept at this temperature for a period of six hours. This period of 12 hours is counted as one cycle and the test is repeated for 10 cycles. The battery is kept under observation for a period of 48 hours once all the cycles are completed. If there is no leakage, fire or explosion then the whole battery lot is deemed fit for usage by the customers. If the sample battery fails, then the whole battery lot is rejected.

3) Vibration test: Whether it is the vibration of your phone itself or it is the vibration due to the bumpy roads, our batteries are tested to withstand even the strongest of them vibrations. The vibration test is carried out with the battery attached to a vibrating platform. The frequency increases from 7 Hz to 200 Hz and then subsequently decreases to 7 Hz in a period of 15 minutes which is one cycle and it repeated 12 times. The total time adds up to 3 hours with maximum acceleration of 8 times the natural gravitational acceleration.

4) Free fall test: It often happens when you accidentally drop your mobile phones, you do check for the screen, the functioning and even the buttons of the mobile phone but you never check the battery and you don’t have to as we at INTEX thoroughly check the batteries if they meet the standards of the free fall test.


In this test the battery is dropped from a height of 1.2 meters three times. Once horizontally, once vertically and once diagonally so as to capture all the possibilities of any fire, leakage or explosion. If the battery fails, this test the whole lot is rejected.

5) External short circuit test: Before the test commences the external temperature is taken to 55 ⁰C. Once this temperature is achieved, the test commences by the application of short circuit condition, where the load resistance is less than 0.1 ohms, for a period of 1 hour. The battery is kept under observation for a period of 6 hours after the test. This test also has the same passing criteria as that of the previous test.

6) Impact/crush test: We make the promise to our customers that even if an object, as heavy as, 10 kilograms is dropped on the battery it can damage the battery but it will most certainly never harm the customer. It is with this test we are able to make such bold claims. The battery is kept on a flat smooth surface on top of which a stainless-steel bar is kept such that its movement is limited. A 9-kilogram mass is dropped from a height of 62 centimeters. If no explosion, fire or leakage is observed then the battery lot is passed.


For the crush test, the battery is kept between two flat smooth surfaces and then it is crushed until the crushing force reaches 13 kN. Again, if no explosion, fire or leakage is observed then the battery lot is passed.

7) Overcharge test: There are many households where the technology of auto cut-off in case of excessive voltage has still not knocked at the doors but we proudly say that we, not only have reached those households, but we also have become a part of those families. Thus, we take it as our onus to safeguard our families if case of such voltage fluctuations also.


This test ensures the trust by charging the battery at twice the maximum recommended charging current. The test is carried out for a period of 24 hours. If no leakage, explosion or fire is observed then the battery lot is passed.

8) Forced discharge test: The battery is discharged with a load of 12 Volts for a period which varies with the battery capacity. If leakage, fire or explosion is observed then the battery lot is rejected.

Some of the additional tests which are carried out to simulate real life situations that approve the INTEX’s insignia of trust are as follows:


1) Salt test: The batteries are kept in an environment which simulates the contact between the batteries and sweat. The battery is kept in the environment for a period of 6 hours and then subsequently it is kept under observation for a period of 24 hours. If there is even the slightest sign of rust, short circuiting, leakage, fire or explosion the battery lot is rejected.


2) Aging test: Before the batteries are ready to be transported to the warehouse, all the batteries undergo a cycle of charging and discharging then subsequently are kept under observation for a period of 24 hours. After the observation period, the battery lot is checked on a sampling basis for functional discrepancy an if no discrepancy is observed the battery lot is transported to the warehouse.


3) Nail penetration test: A nail is mechanically penetrated the battery within a shatter proof glass chamber. The nail stays in the battery for a period of 10 seconds. If there is an explosion or fire, then the whole battery lot is rejected.


The Reliability and safety Lab setup has become a significant milestone in the journey of INTEX Technologies India Ltd. to become the leading mobile manufacturing company in India and mark its presence in the global mobile phone manufacturing market.



Adeesh Sharma: