Kwa nini simu yako inazimika kwenye baridi

Hutokea kila baridi kali. Uko nje kwenye baridi, unatoa simu yako kuangalia ramani, na inazimika. Dakika moja iliyopita ilionyesha asilimia arobaini. Je, betri ilikuwa inadanganya? Kwa namna fulani, ndiyo.

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.

Ndani ya simu yako kuna betri ya lithiamu, na betri si tangi la umeme. Ni kiwanda kidogo cha kemikali. Nguvu hutengenezwa na chembe zinazosogea kati ya pande mbili za betri, na kama kemia nyingi, msogeo huo hupungua kasi inapokuwa baridi. Katika hewa ya barafu, chembe zinasogea polepole sana hivi kwamba betri haiwezi kutoa nguvu ya kutosha, na voltiji yake inashuka. Simu inaona voltiji ya chini, inaamua kwamba betri lazima iwe tupu, na kujizima ili kujilinda.

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.

Uthibitisho unakuja baadaye. Unaingia kwenye chumba chenye joto, kemia inaamka, na simu ileile inawaka ikiwa na asilimia thelathini ya betri, kana kwamba hakuna kilichotokea. Nishati ilikuwepo muda wote, ila ilikuwa imeganda nyuma ya mmenyuko wa polepole. Kwa hiyo wakati wa baridi, weka simu yako mfukoni ndani, karibu na joto la mwili wako. Betri si dhaifu. Ni kwamba tu haipendi hali yako ya hewa.

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.