As the battery is, I do not know, so I'll give him a good review here, In my Oral B Sonic Complete, the cells were not probably the problem. She walked in front of the battery exchange despite extensive charge after a short time and then turned off without further loading and easy on the sink edge, someday suddenly by itself again, made his way to the nearby pool and slept there at some point exhausted and with a discharged battery until I was there in the morning and gave her breakfast. Had suspected a decrepit battery and closed as a result of low supply voltage to faulty reactions of the electronics. But it was not so. Even after the problem-free exchange under YouTube video behavior for a short time was the same as before, until the electronic died completely. Opened again and nachgelötet suspect solder joints with the Lötnadel, but not make a sound and no shop. Now the brush rest so forever and the 11 Euros for the chic Batteriechen equal with her. Too Bad. I found the brush much more pleasant than the Philips Sonicare part that I have now.