Every Tesla owner eventually stares at the range number and wonders. The answer is arithmetic: your rated range now versus new is a percentage, the warranty line is 70%, and the path from 'worried' to 'service case' has exact steps. Type the numbers; get the picture.
Free battery check
Rated range at 100% now (or at your usual limit), what it was new, mileage, year and model — and your charging habits if you want habit feedback. Or paste a service estimate or Tesla's response.
Why this exists
Tesla's battery warranty runs 8 years with a 70% capacity-retention floor (mileage cap varies by model). Normal degradation flattens after the first years; a pack heading for the line behaves differently. Your own screen has the numerator and the sticker has the denominator.
How it works
Range now, range new, miles, year/model, habits. Nothing stored.
Your retention percentage with the arithmetic shown, what's typical at your age/miles, and whether the trend deserves attention or a shrug.
If it's near the line: the service-request wording that asks for a capacity test, what records to keep, and — paid — the script plus the used-buyer battery pack.
Plans
Buyer: used-Tesla owners and shoppers staring at a five-figure pack. Channel: r/TeslaModel3 + r/TeslaModelY + used-EV groups; used-EV dealers licence it.
The full read plus the service-request script that asks for the right test, and the record-keeping list.
Buying used? The test-drive battery checklist, the questions for the seller, and the remaining-warranty math for that VIN's model/year.
Branded checker that turns battery fear into a close.
All prices in USD, handled by Stripe. BatteryCheck is not affiliated with Tesla, cannot test a pack, and its estimate is not a diagnosis — Tesla service confirms capacity by test.