Check Your EV's Battery Health
Calculate your remaining battery capacity in under a minute — all you need is the energy consumption data from your EV's display.
Your readings
- 1
From the on-screen energy app — a recent average is fine.
- 2
The range your car is estimating right now.
- 3
The battery percentage shown on the display.
Your vehicle
Battery health
Enter your three readings above to see your battery health.
Fleet average capacity retention by chemistry type
Want to check your EV's warranty?
See exactly how many months and miles remain on your battery & drive unit warranty.
How healthy is your EV battery?
Better than average for the age and mileage. No action needed.
Normal, healthy degradation. The vast majority of EVs in regular use sit in this range.
Typical for higher-mileage or older vehicles. Worth monitoring; no cause for concern.
Above-average degradation. Review your charging habits and check whether a warranty claim applies.
Most EV warranties guarantee 70% retention. If you're under this threshold within the warranty period, contact your manufacturer's service centre.
Results are estimates based on in-car display data. For a definitive measurement, request a battery diagnostic from your manufacturer's service centre.
What does normal EV battery degradation look like?
0 – 25,000 mi
~3–5%
A small 'settling' drop soon after purchase. Normal and expected.
25,000 – 100,000 mi
~5–10%
Degradation slows significantly. Most owners see very little month-to-month change.
100,000 – 200,000 mi
~10–15%
A long, gentle plateau. Fleet data typically shows ~85–90% retention at this point.
The biggest factor is how you charge. Frequent DC fast charging, storing at 100% for days at a time, and extreme heat all speed up the process. Keeping daily charge limits at 80–90% and using AC charging as your primary source makes a measurable difference over time.
For a full breakdown, see our guide to maximising EV battery life.
EV battery warranty — what's covered?
Most EVs come with a battery warranty that guarantees a minimum of 70% capacity retention for around 8 years, though the exact mileage cap varies by brand. Use our warranty checker to see exactly where your EV stands.
| Brand | Duration | Mileage limit | Min. retention |
|---|---|---|---|
| Tesla | 4yr / 50,000mi | 8yr / 100,000–150,000mi* | 70% |
| Hyundai | 5yr / unlimited | 8yr / 100,000mi | 70% |
| Kia | 7yr / 100,000mi | 8yr / 100,000mi | 70% |
| BMW | 3yr / unlimited | 8yr / 100,000mi | 70% |
| Volkswagen | 3yr / 60,000mi | 8yr / 100,000mi | 70% |
| Nissan | 3yr / 60,000mi | 8yr / 100,000mi | 70% |
| Mercedes-Benz | 3yr / unlimited | 8yr / 100,000mi* | 70% |
| Ford | 3yr / 60,000mi | 8yr / 100,000mi | 70% |
Whichever limit comes first — years or miles. Warranty is generally transferable to subsequent owners. Baseline figures shown; exact terms vary by brand and market — use the warranty checker for your specific model.
Five habits that slow battery degradation
Charge to 80–90% daily
Most manufacturers recommend 80% for everyday use. The lower your regular top-of-charge, the less stress on the cells over thousands of cycles.
Limit DC fast charging
DC fast charging is convenient but generates more heat inside the cells. Reserve it for road trips rather than routine top-ups.
Avoid storing at 100%
If the car sits unused for days, set the charge limit to 50–70%. High-SOC storage is one of the main drivers of long-term capacity loss.
Don't drain below 10% regularly
Occasional deep discharges are fine. Doing it habitually adds cumulative stress — the last 10% is harder on the chemistry.
Park in the shade in hot climates
Heat is the number-one accelerant of battery ageing. Passive cooling between drives helps more than most owners realise.
How this battery health calculator works
Enter three figures from your EV's energy display — the calculator does the rest.
① Energy consumption
Wh/mi or Wh/km
Your average energy use per mile or km, shown on the Energy screen. Use the 30-mile average for the most stable reading.
② Projected range
Miles or km
The range your EV projects based on your recent driving. Found on the energy or range display screen.
③ Battery percentage
% state of charge
Your current battery level shown on your EV's dashboard or display. Take a reading above 50% for better accuracy.
What is EV battery degradation?
Battery degradation is the gradual reduction in a battery's ability to hold a full charge. It happens to every lithium-ion battery — the result is that an older EV will show a lower projected range at 100% than it did when new.
The good news: fleet data shows EV batteries retain around 90% of their original capacity after 200,000 miles. Most owners never notice a meaningful impact on day-to-day driving.
What matters is the pattern. A small early drop followed by a long, slow plateau is completely normal. Continued rapid decline after the first year, or a sudden large loss, is worth investigating.
EV battery specs & facts
Full capacity tables by model and year, cell chemistry, and key degradation stats
Frequently Asked Questions
How does the EV battery health calculator work?
Enter the Wh/mi or Wh/km figure from your EV's energy display, the projected range shown at your current charge level, and the battery percentage. The calculator derives your current usable capacity and — if you select your make, model and variant — compares it to the factory spec.
Where do I find Wh/mi or Wh/km on my EV?
Most EVs show energy consumption on their dashboard or infotainment system. Look for an energy or efficiency display showing average Wh/mi or Wh/km. Tesla shows this in the Energy app, Hyundai/Kia in the EV menu, BMW in the efficiency view, etc.
What is a healthy battery capacity percentage?
90% or above is excellent and typical for newer vehicles. 80–90% is normal for vehicles with moderate mileage. Below 80% may indicate above-average degradation. Most manufacturers warrant their batteries to at least 70% capacity for 8 years.
Which electric vehicles are supported?
We support 25+ manufacturers including Tesla, BMW, Mercedes-Benz, Hyundai, Kia, Volkswagen, Audi, Nissan, Renault, Peugeot, Ford, MG, BYD, Porsche, Volvo, Polestar and many more. Select your make and model to look up the factory battery capacity.
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How a battery health check works without a dealer visit
Every EV, whatever the badge on the bonnet, reports how much energy it actually uses to cover a mile or kilometre — your trip computer or app already shows this as miles/kWh, kWh/100mi or Wh/mi. The battery health calculator compares that real-world figure against the usable capacity and rated efficiency your model shipped with from the factory. If a Hyundai Ioniq 5 was rated for roughly 74kWh usable and 3.3mi/kWh but your real consumption implies less usable energy is available to drive the same distances, that gap is degradation. The same maths works for a Tesla, a Kia, a VW ID.4, a Nissan Leaf or anything else — the tool just needs your model, mileage and consumption figures, not a connection to the car itself.
This approach can't replace a full diagnostic scan for warranty purposes, but it's a fast, free way to sanity-check your battery between services, before buying a used EV, or before deciding whether a professional test is worth booking.
What counts as normal EV battery degradation
Degradation isn't a straight line, and it isn't the same for every chemistry. LFP (lithium iron phosphate) packs — used in the Tesla Model 3/Y Standard Range, the MG4, BYD's entry models and Renault's newest EVs — tolerate regular 100% charges without extra stress and, on the fleet data available so far, often show under 3% loss in the first 50,000 miles with a very flat curve afterwards. NMC and NCA packs — the majority of long-range EVs, including most Hyundai, Kia, VW, BMW and long-range Tesla models — typically lose around 2–3% in the first year (mostly calendar ageing rather than mileage), then settle into a shallower curve of roughly 1.5–2.5% per 50,000 miles after that.
Put together, most well-cared-for EVs land somewhere between 88–94% state of health by 60,000–80,000 miles, and 82–92% by 100,000 miles — with climate and charging habits (see the battery management guide) explaining most of the spread within that range.
How this compares to your battery warranty
Almost every manufacturer now guarantees the battery to at least 70% of its original capacity for 8 years or 100,000 miles, whichever comes first — though the exact mileage cap, and occasionally the retention percentage, varies by brand: some Hyundai and Kia terms extend to 10 years/100,000 miles in the US, Mercedes' EQS and EQE get 10 years/155,000 miles, and Tesla's cap depends on which Model 3 or Model Y variant you have. If your health check comes back close to that 70% line, it's worth checking your exact terms on the warranty checker before assuming a claim is or isn't available.