Understand your range. Charge with confidence.

Displayed range is an estimate

The amount of available range (displayed as miles beside the battery icon) is an estimate based on system efficiency and is calculated by the BMS from its current rated state – but based on all historical transactions. Actual driving range changes with speed, weather, terrain, drag, friction, and general energy use like A/C. The number on the screen alone cannot tell you how much physical degradation has occurred in your car. However your range will drift from its original rated expectations over time.

What range drift means

The Battery Management System (BMS) estimates remaining energy (range) from complex digital measurements and its learned model of the battery. We use ‘range drift’ to describe a change in the current range estimate when compared to its original design range. Separately, uneven cell-group voltage changes can narrow the battery’s usable operating capacity. Diagnostics help distinguish an estimation issue, imbalance issue, or physical deterioration as the root cause of range loss or range drift. Software correction cannot rebuild worn or damaged cells but it can repair range drift in many examples.

Does every Tesla need a 100% daily charge?

At home, yes! But no single percentage suits every owner because you all drive and charge so differently - and your car’s unknown charging history can affect current efficiency. Follow the charge limit shown for your vehicle and its owner’s manual as a guide. For vehicles that recommend an 80% daily limit, this is purely relevant for Supercharging. Tesla advises reserving 100% for longer trips. However, daily charging to 100% using your home charger is very healthy for your battery. Even Tesla says ‘a plugged-in Tesla is a happy Tesla’. Why? Because self-balancing and calibration ONLY occurs when the battery is plugged-in and charging over 75%.

Regardless of your battery chemistry, home charging is always preferable and charging to 100% will keep your battery balanced, calibrated, and healthy for longer. Whenever you are charging in the wild, try not to charge over 80% very often, and always top-up at home to 100% whenever you can.

Should you deliberately run the battery below 5%?

Sometimes – yes! A full calibration and healthy balancing of your battery is accomplished with repeat full cycles. This means a drop to below 5% before charging next time (and not un-plugging until it is 100% full) is healthy for your Tesla. If you have noticed range loss, try this and see how much better your car will deliver range predictions and maintain current displayed usable range for longer. Repeating the 5%-100% uninterrupted charge cycles 10-12 times will manually rebalance your Tesla. Always keep enough charge for parked energy use, and follow the storage guidance for your vehicle.

Why counting plug-ins does not predict battery life

A charging session is not necessarily a full charge cycle. Several partial sessions can together transfer the energy of one full cycle. Battery life depends on balance, calibration, age, temperature, chemistry, usage, and condition. Projected life span is calculated by the maximum design range of the car multiplied by the maximum amount of full charge cycles for the battery – which is 4000 in most cases. So if your car has 300 miles at 100%, it has a life expectancy of 1.2 million miles before needing replacement from an engineering target standpoint. Multiplying rated miles by a fixed number of plug-ins cannot establish an expiration mileage and range loss or degradation is a factor. More frequent partial charging does not by itself prove faster aging but indications from over 1000 customers have noted that range and battery health drop much faster than expected if the battery remains in the 20%-80% charging region most of the time.

After a Range Doctors service

Follow the charging techniques your technician gives for your particular vehicle. Use scheduled charging when it helps you finish charging at your departure time. Keep a consistent routine, and report returning alerts (if any). Perform a full-charge calibration only when specifically recommended. A changed range estimate and projection is useful, but confirmed repair outcomes also depend on strict charging behavior. Make sure you keep your added range by charging properly.