This is really a function of the individual device, whether the device is powered on or not, how much battery life is remaining, etc. In general, however, over 90% of most devices are fully charged in 2-3 hours. 

More importantly we pride our selves on the fact that our chargers charge faster than the original charger.  This is because we use higher quality electronics that supply more power so the internal charging circuit in your device can do its job more efficiently and faster than our competitors.  Don't forget our Gomadic TipExchange product line are covered under our Standard Lifetime Warranty.