It happened quickly, especially on cold winter days: the iPhone went off even though the battery indicated still had some charge. TECHNOLOGY BUTTON explains why this is and what you can do about it.
Does your iPhone battery go crazy too sometimes? Although the display still shows 20 percent charge, the smartphone sometimes simply switches itself off – if it is then plugged into the socket, it suddenly jumps from 0 to 10 percent and more. But why is that?
The iPhone switches off when the battery does not deliver
The answer is quite simple: a battery loses power over time. If the performance is not sufficient to meet the demand, iOS pulls the plug. In this way, the system prevents further damage to the battery.
This happens especially with older iPhones that have already gone through a number of charging and discharging cycles. Charging to 100 percent and emptying to 0 percent are particularly troublesome for the iPhone. So that the battery lasts a long time, it is advisable to keep the charge between 20 and 80 percent. At night, the iPhone does it alone. Here it charges to a maximum of 80 percent and charges to the full 100 percent in the morning shortly before you get up.
In particular, cold winter days have an additional impact on battery chemistry. Here it can happen even faster that the iPhone jumps from “the battery is still enough to go home” to “completely dead”.
What can I do against it?
After it was discovered that Apple was deliberately slowing down older iPhones in order to preserve battery power, the company has become significantly more transparent about batteries. You can now see the details of the battery status in the battery overview in the iOS settings.
This enables you to quickly check how much capacity the battery still has and whether it still supports maximum performance. The capacity indicates how much charge the battery can still hold compared to the delivery condition. It’s not uncommon for between 5-10 percent to be lost in just two years. Depending on how often you charge the battery and expose it to adverse conditions such as heat and cold, the capacity can be severely limited.
More interesting for the question of why the iPhone just dies, however, is the high performance capability. If the battery degrades over time, so too are the voltage it can deliver. If the voltage required by apps exceeds that of the battery, the iPhone simply switches off.
Apple explains this process in detail on the support page. In essence, however, the shutdown has the effect that iOS automatically switches on the performance management. In this way, the system prevents apps from demanding more power than the battery can provide. In plain language this means: the overall performance is reduced.
In the worst case, only replacing the battery helps
Anyone who has an iPhone with a battery that no longer delivers maximum performance can show that the performance is reduced. Then it can happen again and again that the iPhone says goodbye prematurely. The only alternative is to replace the battery. At Apple and certified repair partners, this costs 73.11 euros for the iPhone X or newer and 53.61 euros for the iPhone SE 2020 and iPhone 8 and older.