they are exactly the same:
4) Battery Life – Oral-B Pro 1000 vs 2000
The Oral-B Pro 1000 and 2000 have a short 28 minute battery life. This is one of the downfalls of going for a cheap electric toothbrush. 28 minutes of brushing translates into a week of brushing two minutes twice a day. This is not terrible however it is noticeable when using the Oral-B Pro 1000 and 2000 on a daily basis.
The Oral-B Pro 2000 charges faster than the Oral-B Pro 1000. This is in part due to the higher voltage used in the UK which is 240 volts compared to 120 volts used in the United states. The Oral-B Pro 2000 takes 17 hours to charge from flat and the Oral-B Pro 1000 takes 22 hours. This is a fairly substantial amount of time as leaving it to charge overnight will not bring it to full charge.