Morning shinies
And adding to
@Pigs explanation, the size of that battery's mah also determines how it takes to charge. If you recharging with a fully flat battery that is, if it's above 3.2v it will take less time.
Charging a Samsung 30q 3000mah battery at 2 amp takes an hour and a half from empty to full. Charging the same 3000mah battery at 1 amp will take 3 hours.
A Molical p26a 2600mah at 1 amp takes just over 2 and a half hours (2.6 hours)
A Samsung 20s 2000mah battery at 1 amp takes 2 hours.
And a Samsung 40t 4000mah battery at 1 amp takes four hours. Which is why I charge my 21700s at 2 amp! - it takes only 2 hours.