EV battery life predictor & degradation calculator
See how long your EV battery will really last, how capacity fades year by year, and what a replacement might cost — from how you drive and charge.
How the prediction works
Battery ageing has two parts: cycle ageing (each full charge-discharge wears the cells a little) and calendar ageing (time itself, roughly 1% a year). We estimate your yearly charge cycles from how far you drive and your usable range, then apply chemistry, fast-charging and climate factors. LFP chemistry and gentle home charging in a moderate climate give the longest life.
LFP vs NMC — which lasts longer?
LFP (lithium iron phosphate) tolerates far more cycles and daily 100% charging, making it ideal for high-usage and Indian heat — used in the Tata Nexon/Punch, MG Windsor and BYD. NMC packs a bit more range per kg but ages slightly faster and prefers 20–80% charging.
What actually happens to an EV battery over time
Battery replacement is the fear that stops most Indian buyers, and it is mostly a fear about an event that rarely happens within the life of the car. What does happen is gradual capacity loss, and understanding its shape is more useful than worrying about its end point.
Degradation is front-loaded, then slow
A lithium pack loses a few percent of its capacity relatively quickly in the first year or two, and then settles into a much slower decline. People who read their range figure at month eighteen and extrapolate the early loss over ten years arrive at a frightening number that the physics does not support. The useful question is not “how much will it lose?” but “will what remains still cover my daily drive?” — and for a 40 km commute, the honest answer for nearly every car on sale is yes, for the whole time you will own it.
What accelerates it
- Heat. The dominant factor in India. A car parked in direct sun all day in Delhi or Chennai ages its pack faster than the same car in a basement. Liquid-cooled packs handle this far better than air-cooled ones, which is worth checking on two-wheelers in particular.
- Sitting at a high state of charge. A battery left at 100% for days is under more stress than one sitting at 60%. Charge to full before a long drive, not as a nightly habit.
- Frequent DC fast charging. Occasional use is a non-issue. Relying on it for every charge is measurably harder on the pack than overnight AC charging at home.
- Deep discharge cycles. Regularly running to near-empty and back to full is harder than shallow cycles between 20% and 80%.
LFP and NMC are different trade-offs
Two chemistries dominate cars sold in India. LFP (lithium iron phosphate) tolerates more charge cycles, handles heat better and is generally happier being charged to 100% — at the cost of lower energy density, so you get less range per kilogram. NMC (nickel manganese cobalt) packs more energy into the same space, which is why longer-range cars tend to use it, and in exchange prefers to live between 20% and 80%. Neither is better in the abstract. For a hot-climate city car driven short distances, LFP is an easy argument; for a long-range highway car, NMC usually wins on packaging.
What the warranty actually promises
Battery warranties in India are typically quoted in years and kilometres, whichever comes first, and most cover capacity falling below a stated threshold rather than only outright failure. That threshold is the part worth reading: a warranty that pays out only if capacity drops below a low percentage is a much weaker promise than the headline years suggest. Terms differ by manufacturer and sometimes by variant, so read the actual booklet for the car you are buying rather than a number from a news article — and check whether the cover transfers to a second owner, because that materially affects resale.
If a pack does fail
Out-of-warranty replacement is expensive — it is the single largest cost an EV owner can face, which is precisely why warranty terms matter more than degradation curves. Module-level repair is becoming more common than whole-pack replacement, which helps, but availability varies by brand and by city. Service reach is a real part of this decision: a brand with no service presence near you is a worse bet whatever its warranty says on paper.
Reading the estimate above
The predictor models typical degradation patterns from your inputs. It is an estimate for planning, not a measurement of your specific pack — real-world outcomes vary with climate, charging habits, how the car is parked and how the manufacturer’s battery management software behaves. We do not test batteries ourselves and we publish no laboratory results of our own; our editorial policy sets out where our numbers come from and how estimates are labelled.
EV battery FAQs
How long does an EV battery last in India?
Longer than most buyers expect, and usually longer than their ownership period. Heat is the main Indian-specific factor, so parking in shade and avoiding a permanent 100% charge do more for pack life than anything else you can control.
Does fast charging damage the battery?
Occasional DC fast charging is not a problem and is what the system is designed for. Using it as your only charging method is harder on the pack than overnight AC charging.
Should I charge to 100% every night?
For an NMC pack, no — 80% is a better daily ceiling. Many LFP cars actually ask for a periodic full charge to keep the range estimate accurate; follow the manufacturer’s guidance for your chemistry.
Is battery replacement covered by warranty?
Usually within the stated years and kilometres, and typically if capacity falls below a specified threshold. Read the threshold and the transferability clause in the booklet for your specific variant.
Does degradation affect charging speed too?
It can. An older pack may accept a lower peak charging rate, so DC stops can grow slightly longer over the years even when the range loss is modest.