T4U for Tesla9.1 - App Store

Finally know the real condition of your Tesla's battery.

Not the charge percentage. Not a figure inferred from displayed range. State of Health - how much capacity your pack has left compared to the day it left the factory.

T4U is built by MyBatteryHealth, Europe's reference network for electric vehicle battery diagnostics. Over 70,000 batteries certified.
MEASURED, NOT ESTIMATED

Your car continuously reports the energy actually left in its pack. T4U reads that figure and derives your battery health from it. The vehicle's own computer does the measuring; we only translate.

This works with the car parked and locked. You get a fresh reading every day without anything ever disturbing your vehicle.
WHAT YOU GET

- State of Health as a percentage, with an MBH grade from A to E
- Current pack capacity in kWh, against its original capacity
- Real-world range, calculated from your own data
- Twelve-month degradation curve
- Manufacturer warranty tracking: years, mileage, minimum State of Health
- Battery chemistry, cell supplier, recommended charge limits
- Maximum charging power and Supercharger compatibility
- Live charge level, range and lock status
- Home screen widget, current even while the car sleeps
ADVANCED PACK DIAGNOSTICS

Where a consumer app stops at a percentage, T4U goes down to cell level:

- Voltage spread between the highest and lowest brick groups - the indicator that degrades before you lose any range
- Thermal spread between modules, and the position of the hottest sensor
- Internal pack resistance, measured while driving
- Open-circuit voltage, and voltage per cell
- Real cycle count, derived from lifetime energy consumed

Each of these identifies a weak point by its number inside the pack. That is what lets you document a fault with a professional.
YOUR BATTERY CARD

Generate your score and share it. A social-ready card carrying your grade, your battery health, your mileage and the MyBatteryHealth certification.
THE OFFICIAL MBH REPORT

Issue a digitally signed battery health certificate, verifiable by QR code. A document recognised by automotive professionals, leasing companies and used car buyers - and the strongest argument you have when defending your Tesla's price at resale.
WHAT T4U DOES NOT DO

T4U has no permission to command your vehicle, and never asks for one. It will not wake it, unlock it or move it.

No location data is collected. Distance is reconstructed from the odometer.

Every figure on screen states where it came from and when it was measured. A number you cannot explain is worth nothing.
T4U PREMIUM

The subscription unlocks full cell-level diagnostics, weak point localisation inside the pack, twelve months of history, driving performance and unlimited sharing of your battery card.

€1.99 per month or €14.99 per year.
Terms of use: https://tesla-4u.com/en/privacy-legal/
Privacy policy: https://tesla-4u.com/en/rgpd/

T4U is an independent app published by VIA SAS. It is not affiliated with, endorsed by or sponsored by Tesla, Inc. Tesla, Model S, Model 3, Model X and Model Y are trademarks of Tesla, Inc.

Version History What's New: NEW — Home charging statement (Premium)

Home charging sessions are detected automatically when you plug in.
Each session is priced at your own rate: flat, peak/off-peak or EDF Tempo, split to the minute.
Supercharger sessions added, at the amounts billed by Tesla.
Monthly and yearly signed PDF statements, verifiable by QR code — ready for your expense report or employer.
The Charging tab is redesigned around the month: total, home vs. Supercharger split, every session in detail.

In-car screen

my.tesla-4u.com in your Tesla's browser: highest and lowest cell, module temperatures, front and rear motors, today's consumption, last charge.
Rear motor now shown on Model S/X Plaid and dual-motor Model Y. 9.1 3d ago YOUR BATTERY HEALTH FOR REAL

8.9.3 : Update for Model Y SR

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 9.0 Sep 28 YOUR BATTERY HEALTH FOR REAL

8.9.3 : Update for Model Y SR

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.9.3 Sep 5 YOUR BATTERY HEALTH FOR REAL

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.9.2 Sep 3 YOUR BATTERY HEALTH FOR REAL

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.9.1 Sep 1 YOUR BATTERY HEALTH FOR REAL

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.9 Sep 1 YOUR BATTERY HEALTH FOR REAL

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.8 Aug 19 YOUR BATTERY HEALTH IS NOW MEASURED, NOT ESTIMATED

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.7 Aug 17 YOUR BATTERY HEALTH IS NOW MEASURED, NOT ESTIMATED

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.6 Aug 15 YOUR BATTERY HEALTH IS NOW MEASURED, NOT ESTIMATED

Your Tesla now continuously reports the energy actually left in its pack. T4U reads that figure straight from the vehicle's computer, even while parked. No more deriving health from displayed range.

The direct consequence: one single figure everywhere — home, diagnostics, shareable card and widget. It stays on screen even with no connection.
PACK DIAGNOSTICS, CELL BY CELL

Voltage spread between brick groups, thermal spread between modules, internal resistance, open-circuit voltage, real cycle count. Every weak point is identified by its number inside the pack.
A WIDGET THAT NO LONGER GOES STALE

The widget updates while the car sleeps and while the app stays closed for days. Charge, range and health, current on your home screen.
REDESIGNED HOME SCREEN

Every pack reading now sits in one place. High voltage safety no longer takes up room while everything is fine — and becomes impossible to miss if anything is wrong.
DRIVING EFFICIENCY

Now based on your own car's range estimate compared with its rated range. One value per day, steadier and fairer.
ALSO IMPROVED

- Far more reliable connection to your Tesla account: no more unexplained sign-outs
- Hardened access to your diagnostic data
- Every reading now states how it was obtained, and when
- Displayed range corrected, now matching your car's own screen
- Numerous display fixes

Thank you for the feedback — keep it coming, it genuinely shapes what we work on. 8.5 Aug 11 T4U Battery Edition — Version 8.4

This major update refocuses T4U on its core promise: knowing your Tesla battery's true health.

NEW
- Shareable battery card: generate your certified score and share it on social media (Premium = unlimited)
- Monthly battery recap: track capacity evolution month after month
- Passive polling mode: T4U never wakes your Tesla in the background — only one daily automatic measurement
- Improved Tesla recognition: Model S/X/3/Y/Cybertruck via VIN
- Auto-modernization of trim badges (100D → Long Range, P100D → Plaid)

IMPROVEMENTS
- Simplified dashboard focused on battery health
- More accurate SOH measurement with chemistry normalization
- Abnormal degradation notifications
- 12V battery preservation

FIXES
- SOC display after long sleep
- Widget stability
- iCloud history sync 8.4 Jun 13 T4U Battery Edition — Version 8.3

This major update refocuses T4U on its core promise: knowing your Tesla battery's true health.

NEW
- Shareable battery card: generate your certified score and share it on social media (Premium = unlimited)
- Monthly battery recap: track capacity evolution month after month
- Passive polling mode: T4U never wakes your Tesla in the background — only one daily automatic measurement
- Improved Tesla recognition: Model S/X/3/Y/Cybertruck via VIN
- Auto-modernization of trim badges (100D → Long Range, P100D → Plaid)

IMPROVEMENTS
- Simplified dashboard focused on battery health
- More accurate SOH measurement with chemistry normalization
- Abnormal degradation notifications
- 12V battery preservation

FIXES
- SOC display after long sleep
- Widget stability
- iCloud history sync 8.3 May 25 T4U Battery Edition — Version 8.1

This major update refocuses T4U on its core promise: knowing your Tesla battery's true health.

NEW
- Shareable battery card: generate your certified score and share it on social media (Premium = unlimited)
- Monthly battery recap: track capacity evolution month after month
- Passive polling mode: T4U never wakes your Tesla in the background — only one daily automatic measurement
- Improved Tesla recognition: Model S/X/3/Y/Cybertruck via VIN
- Auto-modernization of trim badges (100D → Long Range, P100D → Plaid)

IMPROVEMENTS
- Simplified dashboard focused on battery health
- More accurate SOH measurement with chemistry normalization
- Abnormal degradation notifications
- 12V battery preservation

FIXES
- SOC display after long sleep
- Widget stability
- iCloud history sync 8.1 May 19 T4U Battery Edition — Version 8.0

This major update refocuses T4U on its core promise: knowing your Tesla battery's true health.

NEW
- Shareable battery card: generate your certified score and share it on social media (Premium = unlimited)
- Monthly battery recap: track capacity evolution month after month
- Passive polling mode: T4U never wakes your Tesla in the background — only one daily automatic measurement
- Improved Tesla recognition: Model S/X/3/Y/Cybertruck via VIN
- Auto-modernization of trim badges (100D → Long Range, P100D → Plaid)

IMPROVEMENTS
- Simplified dashboard focused on battery health
- More accurate SOH measurement with chemistry normalization
- Abnormal degradation notifications
- 12V battery preservation

FIXES
- SOC display after long sleep
- Widget stability
- iCloud history sync 8.0 May 15 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 7.3 May 5 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 7.2 Apr 29 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 7.1 Apr 28 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 7.0 Apr 26 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.9.2 Apr 20 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart, charge and trips Stats,
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.9 Apr 19 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.7 Apr 18 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.6 Apr 17 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.5 Apr 16 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.4 Apr 16 T4U Battery Edition is here.
Connect your Tesla account and instantly see your battery's true State of Health, powered by MyBatteryHealth — the platform trusted by BMW Group, Alphabet and La Poste.
— Battery SOH & A→E grade
— Degradation history chart
— Battery chemistry & warranty details
— Supercharger compatibility
— Official MBH PDF certificate 6.3 Apr 14