# Why are charging times so long for Lithium-ion batteries?

Why do rechargeable batteries (e.g., mobile phone batteries) need sometimes several hours to be fully charged? In other words, what are the physical constraints that don't allow me to charge my iPhone battery in 1 min, for instance?

• I'll leave a proper answer to someone who knows about batteries, but I will put a bet on the answer having to do with heat generation in the charging process. – Asher Jan 11 '15 at 16:57

• I highly doubt that mains wiring is unable to supply $\sim500\mathrm{W}$ of power (my electric teapot takes $2200\mathrm W$). You forget that mains gives you $110\mathrm V$ or $220\mathrm V$ but your charger supplies about $4\mathrm V$ to the battery, and $120\mathrm A$ is the current from charger to battery, not from mains to charger. – Ruslan Jan 11 '15 at 19:37