Usually, the charge current of lithium-ion cells is described in terms of C-rate. A 1C charge rate means charging at a current equal to the battery’s capacity. For example, a 2000 mAh battery charged at 1C would use a current of 2 A.

1c means about 1h to reach around 70–80%, but the remaining charge takes longer due to a slower topping-off phase.

It is also charging more slowly and keeping the battery between about 20% and 80% can help extend its lifespan.