About TeslaBatteryCheck

Who's behind it

I design, build and maintain every tool on this site myself. There's no company or marketing team behind TeslaBatteryCheck — it's one independent software developer who got a little obsessed with what actually happens to a Tesla's battery as it ages, and who wanted to turn that into something any owner could use in a couple of minutes.

It started with a simple, frustrating question that's surprisingly hard to answer well: how healthy is this battery, really? The figures owners are given are vague, the advice online contradicts itself, and anyone buying a used Tesla is mostly guessing. I started gathering real-world data and building calculators around it so the answer could be specific instead of a shrug.

Why this site exists

A Tesla's battery is the single most expensive and most misunderstood part of the car. Degradation worries people more than it should in some cases, and less than it should in others — and there's very little plain-English help for working out where your car actually stands. TeslaBatteryCheck is built for the people stuck in that gap:

• Current owners who want to know whether their range loss is normal for the model, year and mileage — or a sign of a real problem.
• Used-Tesla buyers trying to judge a car's battery health before they hand over the money, without taking the seller's word for it.
• Anyone weighing the running costs — charging at home versus a Supercharger, EV versus petrol, or whether a battery is still inside its warranty.

Every tool is free, works without an account, and doesn't need you to plug anything in or install a diagnostics app — most of them run off the figures already shown in your Tesla's own Energy app.

How the numbers are worked out

The estimates here aren't pulled from thin air, and they're deliberately not based on Tesla's ideal lab figures either. They're built from real-world data — published usable-capacity figures for each model, year and trim, and the consumption and degradation patterns that large fleets of cars actually show over time. The charging and range tools then adjust those baselines for the things that genuinely move the needle: temperature, speed, climate-control load, terrain and battery age.

I'd rather be honest about the limits than oversell the precision. These are well-grounded estimates, not factory diagnostics — useful for spotting whether your battery is healthy, average or worth a closer look, but not a substitute for a service-centre reading. You can dig into the underlying capacity and chemistry figures on the battery specs & facts page, or see them applied per model on the model battery-health pages. For the exact formulas and data sources behind every figure, see the methodology.

When the data improves, the tools get updated — and if you ever spot a figure that looks wrong, I genuinely want to hear about it (see below).

Get in touch

Questions, corrections, feature ideas or just feedback are all welcome — head to the contact page, or email me directly at [email protected]. It's just me reading those, so thanks in advance for your patience.