Generic battery is hit & miss, since all come from China. iRobot originals are also now made in China, but they obviously have better QC.
If we look at US eBay, there are generic battery sellers that claim 3 yrs warranty! Sure... if u buy & shelf for 3 yrs before using. How to verify & claim battery warranty after 3 yrs, their battery got serial number meh? I can assure u the 3 yr warranty is complete BS!
I sell generic Roomba batteries cos on the whole, still no violent complains, or at least, no cases of "accelerated death".
But Scooba generic batteries which I sold long ago was 100% complain (3 upon 3, Bingo!), it was 4800mAh which never delivered >80 mins since day 1 & dropped performance with 1 mth.
I've heard at least 5 other stories about rapid death of generic Scooba batt. I'm now "supposed" to crack open & repair Bakasa's generic batt, but it's on my long "To-Do list", I didn't forget boss...
I also sold a 3500mAh & a 4200mAh Scooba generic in Jan & Feb 2011 respectively, so far no complains. So I guess some generic are of better quality.
My personal experience as shared above is not to "sabo" people, it's to highlight the "一分钱一分货" theory.