Prečo ti telefón vybije batériu v zime

Stáva sa to každú zimu. Si vonku v zime, vytiahneš telefón, aby si sa pozrel na mapu, a on sa vypne. Pred minútou ukazoval štyridsať percent. Klamala batéria? Svojím spôsobom áno.

It happens every winter. You are outside in the cold, you take out your phone to check the map, and it dies. A minute ago it showed forty percent. Was the battery lying? In a way, yes.

Vo vnútri tvojho telefónu je lítiová batéria, a batéria nie je nádrž na elektrinu. Je to malá chemická továreň. Energia vzniká pohybom častíc medzi dvoma stranami batérie, a ako pri väčšine chémie, tento pohyb sa v chlade spomaľuje. V mrazivom vzduchu sa častice pohybujú tak pomaly, že batéria nedokáže vytlačiť dostatok energie a jej napätie klesá. Telefón zaznamená nízke napätie, usúdi, že batéria musí byť prázdna, a vypne sa, aby sa ochránil.

Inside your phone is a lithium battery, and a battery is not a tank of electricity. It is a small chemical factory. Power is made by particles moving between two sides of the battery, and like most chemistry, that movement slows down when it gets cold. In freezing air, the particles move so slowly that the battery cannot push out enough power, and its voltage drops. The phone sees the low voltage, decides the battery must be empty, and switches off to protect itself.

Dôkaz príde neskôr. Vojdeš do teplej miestnosti, chémia sa prebudí a ten istý telefón sa zapne s tridsiatimi percentami batérie, akoby sa nič nestalo. Energia tam bola po celý čas, len zamrznutá za pomalou reakciou. Takže v zime nos telefón vo vnútornom vrecku, blízko tepla svojho tela. Batéria nie je slabá. Jednoducho nie je fanúšička tvojho počasia.

The proof comes later. You step into a warm room, the chemistry wakes up, and the same phone turns on with thirty percent battery, as if nothing happened. The energy was there all along, just frozen behind a slow reaction. So in winter, keep your phone in an inside pocket, close to your body heat. The battery is not weak. It is simply not a fan of your weather.