Originally Posted by alanHd
From the amazon site
Fully charges in 3 hours via the charging accessory, or slightly longer with other micro-USB power adapters that you may already have. Charges in approximately 11.5 hours from your computer via the included USB charging cable.
why would it take longer from a any other micro-USB charger?
The power fast charger delivers more power for charging.
Power fast: 1.8 amps not sure of the voltage but guess about 5 volts.
The charger that came with my kindle: .85 amps at 4.9 volts.
Going by these figures, the power fast charger delivers about 1 amp more power.
Other adapters may be different, I used the specs from my kindle keyboard 3G.