Electric Car Battery Life in India: Replacement Cost, Warranty & How Long It Lasts

The conversation around EV battery longevity has been happening in India for over a decade. Since the battery technology is still going through a lot of transitions, there are quite different opinions on battery life and its degradation process. A person who bought an EV 8 years ago will have a very different view on its life compared to a person who bought one a couple of years after, because of the constant changes happening in battery technology. 

Therefore, it is important to know how far we have come in terms of EV battery technology so that you can make an informed decision when it comes to buying an EV. In this article, you will get to know about the Indian EV battery landscape, battery life cycle, replacement costs, warranty reality and more. 

How Long Does an Electric Car Battery Last in India?

Battery chemistry has a significant impact on its life. LFP (Lithium Iron Phosphate) and NMC (Nickel Manganese Cobalt) are the common battery types found in Indian EVs. While LFP has excellent cycle life and thermal stability, it comes with lower energy density which in turn makes the battery bulky thereby taking up more space. 

When it comes to NMC batteries, their sensitivity to heat may reduce life in the Indian climate condition if it doesn’t have proper heat handling technologies like BMS. However, battery chemistry alone cannot determine the life of a battery. It is a combination of other factors as well.

Now, what does “battery life” actually mean? 

The life of an EV battery or its aging can be interpreted as a combination of two key factors – cycle aging and calendar aging. Cycle aging is equivalent to the full charge-discharge cycles that a battery goes through ie; if an EV manufacturer says, for a particular EV, the battery cycle life is 2000, that does not mean you can only charge the car 2,000 times. A full equivalent charge-discharge cycle (FEC) means using an amount of energy equivalent to 100% of the battery’s capacity. 

Suppose, a battery is 80 kwh and it is charged upto,

80 kwh that is 1 cycle.

Use 40 kWh = 0.5 cycle

Use 20 kWh = 0.25 cycle

Four times using 20 kWh = 1 cycle

Therefore, if you drive 30% of the battery’s capacity and recharge it, you’ve used roughly 0.3 equivalent cycle, not one complete cycle.

This does not mean that the battery will die after 2000 full charging cycles. After 2000 cycles, it might lose its charging capacity to 90% or 80% or less as per the manufacturer guidelines. But will continue working for considerably longer, with progressively lower capacity.

For example:

If a new battery is 60 kWh

After degradation it reduces its capacity to 80% and becomes 48 kWh.

The car hasn’t suddenly stopped working. Its range has simply decreased. Hence, battery life is essentially the sum of calendar ageing and cycle ageing coupled with the conditions (temperature, SOC and charging/discharging behaviour) in which it operates.

Battery Degradation vs Battery Failure

As we have already pointed out above, battery degradation and battery failure are not the same. While degradation reduces the battery’s capacity to store and deliver energy gradually, failure means something more fundamental has gone wrong such that the battery, or part of its battery system, can no longer perform its required function safely or reliably. 

An EV battery consists of a cell, module and pack that contains battery management system (BMS), cooling/heating system, contactors, fuses, sensors, wiring/busbars, high-voltage connectors, etc,.

So “battery failure” can mean several different things. It could be a cell failure where an individual cell develops an internal problem like internal short circuit, excessive resistance, abnormal self-discharge, physical damage, and severe capacity loss. One bad cell can cause the BMS to detect an unsafe condition and restrict the battery.

Then comes module failure, several cells are grouped into a module. If a module develops a fault, the vehicle may detect that the module’s voltage or temperature is abnormal.

Depending on the battery design, the manufacturer might replace the module rather than the entire pack. 

Up next comes battery-pack electrical failure, the cells themselves may still be healthy, but something like a contactor, fuse, connector, sensor, busbar can fail. The car may then refuse to start or charge because the high-voltage system cannot safely operate. 

Hence “battery degradation” “battery end of life” and “battery failure” should not be treated as synonyms. A battery can be substantially degraded while remaining perfectly functional, and a relatively young battery can suffer a component or cell failure unrelated to ordinary ageing. 

When a normal degradation reaches an unacceptable level for the owner or a cell failure makes the entire battery unusable, at that point, battery replacement becomes the solution.

How Much Does an EV Battery Replacement Cost in India?

Battery replacement is one of the major topics regarding EVs in India. As India only adopted EVs a few years ago, there are not many users who would have gone through the replacement procedure. Thus, whatever information we currently have won’t be able to give us a complete picture of the situation. 

Although, various EV car companies have an estimate of the battery replacement cost as shown in the below table.