Now when it comes to charging not all smart chargers are equal. There are various methods to determine when the battery is full and some are more accurate than others. There are also low end chargers that charge batteries in pairs.
The better chargers let you specify the mA its putting in so the time all depends on how low the battery is but too fast of a charge is bad and sometimes too slow of a charge can lead to under or overcharging.
Thats why the chargers like the higher end maha's and lacross let you specify the current.
If your going to use rechargeables then get a decent charger from the start, don't do as I and run through a half dozen $20-$30 each and end up replacing them with one good one in the end.
To make a long story short, in the early 2000's I gave up on rechargeables, the higher capacity were coming out then and suffered from high self discharge and the chargers I had weren't doing a good job of charging. I started spending a lot of $ on lithium's until I learned about eneloops and got some of them and a maha charger.