I say usually because in the last few weeks we've covered several companies that have seemingly managed to pull off the impossible to get their electric cars to go further per charge without any physical changes to the cars battery pack and to drive trains we've even seen companies like Tesla Jaguar and Audi magically unlock extra range via software updates and so we've had some of you reach out and ask us how that's possible after all you can't add extra storage capacity to an existing battery pack so what's going on I'm not going to go into the specifics for each automaker here.

but what I can share are some of the ways that such magical range expansions are possible and they all boil down to a couple of key things revised battery management software revised power train control software and some software re-calibration let's start with the batteries and the dirty little secret that you probably don't know ful isn't full and empty isn't empty lithium-ion cells don't like being completely full or completely empty and while it is possible to technically charge a lithium-ion cell to its fully charged voltage and then fully discharge it.

doing so can prematurely age the cell I'm not going to go into the electrochemical reasons for that here but it's all to do with the way in which the cells operate at the molecular level and the heat that can cause irreparable change to their structure when they're overcharged or fully discharged and to keep your car's battery cells operating for extended periods of time with as fewer problems as possible your car doesn't actually charge its battery to its maximum state of charge nor does it allow you to discharge it below a certain set level this means that when your car says it's 100% full it's probably technically between 80 and 90 percent full and when it says it's fully empty they could have anywhere from 10 to 20 percent cell level charge sitting there that you can't see or use.

exactly how much you can't use depends on the automaker and their approach to battery management some automakers are on the side of caution and hide a lot of the physical capacity of the car's battery pack some automakers let you use more some even switch how much you can use depending on which charging and driving mode you happen to be in automakers often start with more conservative battery management and then after they've got plenty of data from their customers cars decide to unlock more capacity for use by their customers.

the reason they do this is because unlike some battery chemistry which have a very obvious and continual drop-off of voltage as the battery discharges lithium-ion battery cells have a much more consistent cell voltage throughout the discharge process until the very last few percent when the cell voltage drops off the metaphorical cliff by which point you may have already damaged your battery cell it's harder to detect those tiny drops in voltages so automakers play it safe when they have more data to predict how a battery will behave they're more confident in how those cells will discharge and therefore they give you more access to more capacity.

several automakers including Tesla and Audi have done just that essentially moving the goal posts as to what the car considers full and what the car considers empty sin a software tweak rather than a physical tweak the change can be pushed in a software update next let's look at power train software like battery management software and honestly pretty much everything else in a modern electric car it is all down to the code back at the turn of the 20th century electric cars used electromechanical controls to govern how much power went to their direct current motors but today it's all done using digital three-phase controllers that control how much power is sent to the motor by pulsing power on and off at the correct frequency.