However, 'it won't ruin the battery' does not mean it has no impact at all. Batteries degrade over time and depending on the charging method. Lithium-ion batteries age fastest when subjected to extreme levels: 0% and 100%.
Keeping the battery at full charge for extended periods creates additional stress on the cathode and electrolyte. Therefore, many devices use 'slow charging' or temporarily stop the process at 100%, replenishing the charge only as needed.
Threats to Battery and Manufacturer Recommendations
The biggest threat to the battery is heat. If the phone is connected to charge and simultaneously used for resource-intensive tasks, this can affect the battery's lifespan. The 'Optimized Battery Charging' feature on iPhone and Battery Protect on Samsung help keep the battery in good condition.
Other Android manufacturers also include similar features that dynamically adjust energy supply based on user habits. These processes slow down battery wear. However, it is important to avoid high temperatures, intensive use during charging, using cheap cables, and significantly old batteries to preserve battery health.
In conclusion: Modern smartphones have smart charging systems that help prevent battery damage from overcharging. However, keeping the battery at 100% charge for extended periods can affect its lifespan. Manufacturers provide recommendations regarding optimal usage and charging, but it is also important to avoid high temperatures and using cheap or damaged accessories.