If Electricity Moves So Fast, Why Does It Take So Long For Your Phone To Charge?

Have you ever wonder why does your phone take so long to charge even though electricity moves so quickly?

Well, the answer to that is simply because phone batteries do not store electricity. They store chemicals and when those chemicals react they make electricity to power your phone. Plugging in your phone doesn’t fill your phone with electricity! Instead, it is using electricity to move the chemicals back to where they were.

So what do you mean by ” move the chemicals back to where they were”?

Well, the way batteries work is through the movement of electrons. That is part of the reason you see batteries labeled nickel cadmium and lithium ion. You have an anode, a cathode and a salt bridge between the two. For example, in a nickel-cadmium battery, a rod of nickel in the positive side and a rod of cadmium in the negative side both sitting in a potassium hydroxide solution. Nickel metal is reduced and the cadmium is oxidized as the battery discharges. This gives up 2 electrons and ionizes into the KOH solution. When fully discharged the chemical reaction is actually at equilibrium.

If you were to look at the nickel rod at full charge then at full discharge you should be able to see that a lot of the metal has dissolved from the nickel rod and cadmium accumulated on the cadmium rod. When you recharge it you reverse the flow of energy and drive the chemical reaction back up the river as an example so that it can discharge and release electrons again.

And when that happens, the battery is able to make electricity again.

Furthermore, the chemical reactions are able to make a small, light battery power your phone all day is very high energy, which means your phone battery could easily become a small explosive if the reactions occurred in an uncontrolled manner, so the phone makers carefully design the battery to remain under control.