Optimal maintenance of smartphone or tablet (actually, there’s no real difference in terms of battery technology between Android & Apple) batteries requires not only the right procedure for discharging, but also for charging. When you buy a new battery, the rechargeable batteries have a charge level of 40 to 50 percent; some devices are also charged up to 80%. Conditioning, which is often necessary with old mobile phones, does not have to be done with lithium batteries. It is therefore not necessary to charge the batteries completely after delivery.
Basically, it didn’t make sense to fully recharge the batteries of your device. A state of charge between 40 and 80 percent, which is reached after charging, is particularly favourable. Therefore, it is better to charge your batteries half times more often than to leave them on for several hours overnight. Slow charging is therefore synonymous with gentle charging and can considerably extend the service life of smartphone batteries. Many manufacturers who want to guarantee a particularly long service life of their batteries have therefore also changed their charging electronics; whereas a few years ago the batteries were pumped up to the maximum charge cut-off voltage, today the batteries are switched off earlier.
Last but not least, when charging batteries, it is important to keep in mind that, contrary to popular opinion, charging from 0% to 100% does not have a positive effect on the capacity of the batteries. This is only the case with rechargeable batteries that work with nickel and cadmium, where selective pumping can actually increase capacity. Charging the battery from 0% to 100% does not have a positive effect on the capacity of lithium-based batteries.
In summary, the following applies: Fully charging and discharging tablet or phone batteries has a negative effect in the long term. In both cases, slow charging and discharging is usually better. However, it can also be advantageous to carry out a complete charging and discharging operation at least from time to time: In this way, the charging electronics are readjusted – more precise and accurate charging level indicators are the result.