Frequently Asked Questions

Yes. VoltValue uses read-only access to Tesla's official Fleet API. We can read battery telemetry but cannot send any commands to your vehicle — we cannot unlock, drive, charge, or control any function. Data is stored encrypted, and you can revoke access at any time from your Tesla account.

Once per day — and only while your plan is active (30-day trial or 180-day plan). Our system sends a single wake command at 02:00 UTC to fetch a fresh daily battery reading. It takes a few seconds, then your car goes back to sleep. Once your plan expires, we stop waking your car automatically.

SoH is the median of up to 180 daily readings from Tesla's Fleet API, not a single snapshot. Each reading derives usable pack capacity from the current battery level and Tesla's reported range, then normalizes against the vehicle's original nominal capacity. Using a median makes the number stable and resistant to any one bad day. Full methodology →

VoltValue needs at least 7 days of battery readings before issuing a Passport. This ensures the State of Health figure is based on a reliable median rather than a single snapshot. You can track your progress on the dashboard — the Issue Passport button becomes active once 7 days of data are collected.

This is normal. SoH is estimated from your battery's usable range relative to its rated capacity — and range varies with temperature, driving speed, tire pressure, and cabin heating/cooling. A reading on a hot day after highway driving will look lower than one on a cool day after city driving. This is why VoltValue uses the median of up to 180 days of readings for your Passport, not a single snapshot — to smooth out these daily fluctuations and give a stable, representative number.

They may differ slightly. Tesla service centers use a direct BMS diagnostic tool that reads battery health at the hardware level. VoltValue calculates SoH from a weighted median of Fleet API readings compared against the WLTP-rated range for your model. Both methods aim for the same result, but small differences (typically within 1–3%) are normal due to different measurement approaches. If you see a larger gap, feel free to contact us.

The ฿299 plan covers 180 days of daily battery monitoring. Within that period, you can re-issue your Passport as many times as you like at no extra cost — each new Passport reflects the latest data. After 180 days, monitoring ends and the Passport is locked at its last value.

Unlimited Passport re-issues and a tamper-evident certificate with a QR code that buyers and dealers can verify themselves. The free 30-day trial includes full dashboard access — SoH, degradation rate, and charging history — but does not include a Passport.

Tesla via the official Fleet API today. Additional brands coming soon.

B2B is for dealerships, used-car platforms, finance companies, and inspection partners who need verified Passports for vehicles they handle. Partners can issue verification requests directly to a customer's email and receive a verified Passport once the customer connects their Tesla. Contact us for partner onboarding →

Scan My Tesla reads raw BMS values via an OBD2 adapter you plug into the car — great for enthusiasts, but the result is just a screenshot. VoltValue connects via Tesla's official Fleet API, collects readings automatically every day for up to 180 days, and issues a shareable, QR-verifiable Passport that buyers and finance companies can trust. Full comparison →

If a Passport fails to issue due to an error on our side, we refund in full.