mah has zero to do with vaping time - how often you vape and power settings are the issues.
A 2000 mah battery for a light vapor at low wattage will last a hell of a long time. Same battery - crank it up to 10 watts - not so much.
Anyone giving "time" doesn't understand - it is ALL depending on HOW often you vape - and the settings of the device. 100 mah=1 hour is garbage.
There is a great
explanation of mAh here. Starts at paragraph 5.
In a nutshell, if you vape at a given vape pace with a device that draws a certain number of amps, you will be able to vape for a certain amount of time. The formula is mAh/mA current draw = vape time.
If you double your vape pace with no other change, you halve your vape time per charge.
If you double the amps with no other change, you halve your vape time. Increasing the voltage increases the amperage for a given resistance.
If you double the mAh of the battery with no other change, you double the vape time.
1 hour of vape time per 100 mAh of battery capacity is a generally accepted starting point for an 'average' vaper.
Hope this helps.