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About this tool
Estimate range and battery capacity trends from your EV's charge logs.
The EV Battery Degradation Analyzer turns a log of your own EV battery observations — date, usable kWh, displayed range and odometer reading — into a state-of-health trend: each entry is expressed as a percentage of the pack's new usable capacity, and the first and last entries give the total kWh lost and the loss normalised per 10,000 km driven. It is for owners tracking whether their pack is fading faster than expected, using their own repeated readings rather than a one-off dashboard number.
Open EV Battery Degradation Analyzer on AltFTool — it loads instantly in your browser.
Paste one reading per line into Battery observations as date | estimated usable kWh | displayed range km | odometer km, and set New usable capacity (kWh)
The analyzer converts every row to a percentage of the new capacity and tabulates Date, Usable kWh, % of new, Range km and Odometer
Read the latest capacity percentage plus the Capacity change, Odometer span and Change per 10,000 km rows, then use Copy or Download to save the summary
The kWh change is divided by the odometer span and reported per 10,000 km, which is the figure that compares meaningfully between cars driven differently.
The table shows each observation with its capacity, its percentage of new, its displayed range and the odometer, so you can spot the outlier reading rather than average it away.
Displayed range often falls faster than true capacity; keeping both columns makes it obvious when the drop is seasonal driving rather than the pack.
The pack's estimated usable energy at that date, one line per observation in the form date | usable kWh | displayed range km | odometer km. Take it the same way every time — a full charge reading, an app-reported figure, or an OBD scan — because mixing sources produces a trend that reflects your method rather than the battery.
There is no single number, but the widely used industry benchmark is that packs are expected to retain roughly 70% of original capacity over the warranty term, which for most manufacturers is 8 years or 160,000 km, whichever comes first. Check your own warranty document for the exact threshold, because both the percentage and the term vary by maker.
Because the range estimate is computed from recent driving efficiency, not from the pack alone. Cold weather, faster driving, roof boxes and winter tyres all cut km per kWh, so range can fall 20% or more in winter while usable capacity is essentially unchanged — which is why both columns are tracked separately here.
No. This is a trend estimate built entirely from the numbers you type in, with no access to cell-level voltages, balancing data or fault codes. Use it to decide whether a professional state-of-health diagnostic is worth booking, and rely on the official test for a warranty claim.
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