Tesla battery certificate: SOH measured on your car

What the certificate is for

The battery is the most valuable part of a Tesla. The certificate gives you a measured, dated figure and a way to check it.

Selling

Reassure buyers with a dated document, the full VIN and the SOH curve: a more credible listing and fewer doubts about the battery.

Buying

Ask the seller for the certificate, scan the QR code, then compare the values with those recorded by ioDek and the VIN with the car.

Tracking

Keep a record of your battery's condition, for example before the warranty expires or before you change cars.

What the certificate contains

A two-page PDF in the language of your account. Example below, with a fictitious VIN.

• The vehicle: model, model year, full VIN, mileage on the measurement date, battery pack, chemistry and original capacity
• The result: SOH in %, margin of error, estimated current capacity, Tesla range at 100% charge, charge level at the time of measurement
• Tracking: SOH curve since ioDek started tracking, and number of days with a reading
• Cells, usual pack temperatures and charging habits: energy charged, usual maximum charge, Supercharger share
• The method, its limits and a QR code to the verification page

No name, no email, no location: only the car and its battery.

Why you can trust it

The SOH is the capacity estimated by your car's battery management system (BMS), read through Tesla's official API with your consent, divided by the capacity of the same pack when new.

Estimate from the VIN alone

• Average for cars of the same model and age
• Says nothing about how this car was charged and used
• A single value, with no tracking and no margin of error

ioDek certificate

• Measured in your car, every day it reports its capacity
• Tracked over time: at least 5 days with a reading, spread over at least 7 days
• Margin of error shown: at least 2 points, 3 for an LFP battery
• Charge level at the time of measurement, and whether the car was charged to 100% in the previous 48 hours

Tip: take a reading after charging to 100%

The car's capacity estimate is more reliable right after a full charge, especially for LFP batteries. Charge to 100%, let the car send its data to ioDek, then issue the certificate.

Method and limits

The certificate is valid on the measurement date: it does not guarantee the future condition of the battery and does not replace a service center diagnosis (capacity test, insulation check).

How the buyer verifies it

For a certified certificate, ioDek's verification page is the reference, not the document you were shown.

1. Scan the QR code · Or open iodek.fr/certificat/ followed by the code printed at the top of the certificate.
2. Compare the values · The page shows the SOH, capacity, mileage, VIN and tracking recorded by ioDek when it was issued. Compare them with the PDF, and the VIN with the car.
3. Check the file · Choose the PDF you received: its fingerprint is computed in your browser, without uploading the file, and compared with the original's. The original PDF is also digitally signed.

A non-guaranteed certificate (Free account) cannot be verified: the page says so without showing any data.

Certified or non-guaranteed

Two versions, same measurement. Only the certified version can be verified online.

Certified · €19.00 per certificate

“Readings certified by ioDek”

• For Standard and Premium subscribers and Founders
• Verifiable online: data, PDF file and digital signature
• QR code to the verification page

Free: with an annual subscription · after 1 year of subscription · for Founders. At most 4 free certificates per car per month.

Non-guaranteed · Free, for all accounts

“No ioDek guarantee - Free account”

• Same measurement, same content
• Not verifiable online: the verification page says so without showing any data
• Useful for keeping track of your own battery

See plans and pricing

Frequently asked questions

How do I find out my Tesla's SOH?

Link your Tesla to ioDek, even with a free account: ioDek reads the capacity estimated by the car's BMS and compares it with the original capacity of the same pack. The Battery page shows the SOH and its trend; the certificate puts it in a dated, verifiable PDF.

What is a good SOH?

There is no single threshold: compare the SOH with the car's age and mileage, look at the trend rather than one value, and allow for the margin of error. For reference, Tesla's battery warranty covers at least 70% capacity retention over the warranty period.

Is the certificate useful for selling?

Yes: buyers of a used Tesla want to know the battery's condition. The certificate answers with a dated measurement, the VIN and tracking over time; with the certified version, buyers can check everything themselves instead of taking your word for it.

How much does the certificate cost?

The non-guaranteed version is free for all accounts. The certified version, for subscribers, costs €19.00 per certificate; it is free with an annual subscription, after 1 year of subscription, and for Founders, up to 4 free certificates per car per month.

Does it work for every Tesla?

Any Tesla linked to ioDek through the official API, with the virtual key, whose battery pack is in ioDek's reference list. It needs at least 5 days with a reading spread over 7 days, including a recent one: the Battery page shows what is missing and when the certificate will be available.

What does the buyer see?

The PDF, and by scanning the QR code on a certified certificate, ioDek's verification page: SOH, capacity, mileage, VIN, tracking over time and issue date, as recorded by ioDek. They can also check that the file they received is the original. Your name, email and location never appear.