One thing I love about my 9650 is that charging time is so fast! The batter lasts a long time but when it does get low I'm thankful it charges so quickly.
Is the charging time the same on the 9900? One thing I didn't like about my Android was it took a long time to charge it, especially fully. And I had to charge it a lot.
What I have noticed is that when I charge my Bold with the PB charger, it gets to 100% in less then 2 hrs. When I look at Device Analyzer>Battery Tests>Battery Drain Trends>Details, my battery charge rate is of 53.82%/hr.
I don't have any technical backing, but just leaving the BOLD 9650 less than a week ago, the 9930 charges to 100% faster......about 30% faster.....IMO. That's with the phones charger
When I had my 8330 and 9330 I could "quick Charge" them. What I mean is leave the Phone alone for 1/2 hr and they were 100%. Now with my 9330 it takes an hour with my bb wall charger. No complaints
With my Bold 9900 and the default wallcharger I need around 2 hours to get the phone up to 100% charge - from almost zero. Device Analyzer states an average charging rate of around 50% per hour.