One of the main problems while charging till 100% is a battery ageing, caused with a full charge. It seems that (depending on chemistry) single complete charging causes about four times more damage than discharging a battery to 0% capacity (maintaining "safe" voltage of 2,5V or higher.
Also, charging is controlled via a battery controller, with a passive (resistive) balancer. Such balancer cannot monitor every single cell or pouch inside a battery. Cells are stacked in groups of parallel-serial modules. Such complete modules consisting of few cells are controlled via balancer as a single energy storage units.
Different cell temperatures, state of their health or even accidental damages or production differences between them may cause different internal resistance of them and finally cause to overvoltage a single cell, while the whole module, that consists such cell looks appropriately powered. It is almost impossible to avoid that during battery life without adding monitoring and balancing units to every single cell.
Car manufacturers solve this via charging during final phase with constant voltage, that is set below 4,2 V (like 4,12V or so) to decrease the chance of overvoltage occurrences.
What to do?
First, the simple answer is: do not charge fully! Some cars (like Tesla) can be configured to stop charging at 90% or lower state of charge (Tesla highly suggest this to users to avoid battery depleting). You can also try to monitor your state of charge and switch off charging at a proper level.
Alternatively, you may use Accelev v2 and switch on BatteryCare group of functions. One of them is "No full charging". When the charger detects near-full state, it stops charging (usually at a level of 90-95%). This manner will be excellent for the longevity of your battery, primarily as a charging mode for daily commuting.
Sometimes we need to have a full available capacity (for example - before a long trip). In such a case, we can start charging without button "no full charging" pressed. A charger will charge till near-full state, and then - it will control current with steps down, to keep lower voltage than the typical one. Last charging phase may be more extended (slightly), but a battery will stay at about 4V per cell (not 4,12V). A charger will learn proper finalising characteristics so that the next full charges can be even smoother and shorter.
We believe that BatteryCare can help with prolonging your battery life.
BatteryCare focuses on finalising of battery charging. This phase starts, when the voltage reaches the maximum permitted (usually 4,12 V per cell). During that phase, when imbalance, different cell temperatures along with a group of cells controlled by single BMS node, or just partial cell failure occurs, it is quite possible to cause overvoltage at some individual cells, and through that - cause ageing and breakdown of whole battery (after some time).
BatteryCare during the first pass (first full charge) tries to learn car charging characteristics, and memorise it. Also, it reduces charging amps to minimise the time of being at full voltage to about 15% of the original time. Such finalising stage can be up to 15% longer than conventional charging.
When learning is done, BatteryCare charges the car till full with current adapted to keep not more than 4,0V during finalizing. This adaptive method reduces time loss at the finalising stage to 5-10% while the battery will be less than 5% of finalising time in "danger zone".
When we compare factory BMS behaviour, it would be focused on a maximum speed of charge within a safe zone (4,12V or so). This safe zone is calculated as an optimal balance between speed of charging and risk of damage - for all cells staying in the exact same condition. As it is impossible to measure internal resistance and temperature of every single cell (most of the batteries have 2-4 thermosensors), such manner is good within laboratory conditions.
Car manufacturers want to advertise faster charging. Reducing the max. voltage per cell to 4,0V (with BatteryCare) delays charging during last phase (finalizing) but highly increases safety (especially when the car is intensively used, it is warm, or very cold). It may not help, when the battery is new (first 5000 - 10000 km), but it starts to be positively influential later, when cells are not as equal, as they were at the start of their life.