Cell phones run out of power faster in the cold: it’s the lithium batteries’ fault

It’s not an impression, it’s true that cell phones do they download faster than usual when we are in places a low temperature. It is due to lithium batteries, which are used not only in smartphones, but also in electric and hybrid cars. This type of battery has enormous advantages over traditional batteries, but they suffer damage if stressed by the cold, because the electrolyte inside them becomes more viscous and offers more resistance to the passage of electrons. Many manufacturers, for example, advise against charging your smartphone at temperatures below 5 °C.

A premise: how the lithium battery works

The operation of lithium batteries is based on a chemical reaction, called oxidation-reduction, which consists in the exchange of electrons between two poles: the anode and the cathode. When the battery discharges, the anode gives up electrons (oxidation), while the cathode receives them (reduction). Electrons move within a substance called electrolyte, which can be both solid and liquid. And how does it charge the battery? By reversing the flow of electrons, from the cathode to the anode.

cold cell cathode anode discharge

Because the cold “slows down” the battery

But how come the Freddo Does this type of battery discharge faster? Why slows down the chemical process which we saw above. In fact, the electrolyte becomes more viscous as temperatures drop, that is, it becomes more difficult for the electrons to move inside it. This resistance causes the available energy is reduced and then the telephone it downloads faster.

This “discharge rate” can be almost imperceptible, we often don’t notice it. But when temperatures start to drop below zero, the difference is clear: a –20°C there drums of our smartphone lasts the 60% of its normal.

cold smartphone discharged

The cold is also a problem when we charge our cell phone. For the same reason just seen, also the phase of loading he comes slowed down, always due to the difficulty of moving the electrons, in this case from cathode to anode.
This has consequences not only on the charging speed, but also on the“aging” of the battery: the more we “strain” it by charging and discharging it at low temperatures, the more it deteriorates, reducing its life cycle.

Despite this limitation, lithium batteries however, they remain the best solution in terms of energy storage capacity, life cycle and safety. Special systems are used in electric cars to keep the batteries at the right temperature. As far as cell phones are concerned, the advice is: keep them warm!