Can anyone confirm the kind of battery the HBH-660 has? I have returned both an HBH-60 and an HBH-600 because the NiMH battery developed a memory effect VERY quickly. I know that it seems the HBH-660 is the headset to use with the 650, but I don't wanna mess around with another battery. I need to be able to leave it charging in the car when not using it and then use it on the way to work, leave it charging while at work, and work on the way home. Doing that my HBH-600 was down to less than 30 minutes of time in a week.