Hi, although you state that it isn't the rtc battery, another place in the forum has asked the same question and the answer was stated that it WAS the rtc battery.
I have ran the battery test in my hp support assistant program and it states that the battery is functioning correctly, but due to normal aging of the battery, the battery life between charges has reached a point where your battery is no longe ruseful. You should consider purchasing a new battery to optimize your computing experience.
Please let me know for certain - is it the battery that I remove from the back, or is it the rtc battery? Thank you for your help.