Originally posted by Not a Number You can use a charger with an output greater than the max draw of the device being charged. The device will only draw up to it's maximum rating. If you use a charger with a lesser maximum output than the requirement of the device than it will take longer to charge.
The charger/power supply amperage should be equal or greater than the device as the device will only draw up to its rating.
For example one power bank I used would take 2-3 hour to fully charge from "empty" at 2.4 amps where as at 0.7 amps it would tak10-12 hours.
I think your statement - the device will draw up to its maximum rating - does not apply to batteries, only if it has integrated circuits , like smartphones do. Only users draw what they need, like motors and such.