Notebook Hardware and Upgrade Questions

Hi, I am facing an issue with the battery charging of my HP Pavilion 15-CS2082TX since yesterday night. See below sequence of actions:

1. I had almost finished my work and the battery low message popped up since the battery had drained to 15%. I turned off my laptop and took it to the charging point. However, I noticed that the battery white light is continuously blinking even though the laptop was turned off.

2. Since the white light had never blinked before, I felt something is wrong and put the laptop on AC power for charging for some time to check whether the blinking light stabilizes. However, even after 5 mins, it was still blinking.

3. I pressed the power button to power on the laptop, and it did power on without any issues. The battery logo was showing as plugged in.

4. I shut down the laptop again and kept it connected to AC power for charging the batteries overnight.

5. Today morning, the light was still blinking. I turned on the laptop and observed that the battery had not charged. It was at 19% only. I guess that 4% was charged while I had turned on the laptop before leaving it on charging overnight.

6. I kept the laptop turned on and connected to the AC power. The battery got charged 100% within 1.5 hours.

To summarize from the above experience, following are the issues:

a. the battery white light keeps on blinking irrespective of whether the laptop is turned on or off, or whether it is connected to AC power or not, 

b. the battery does not get charged when the laptop is turned off, and only charges while the laptop is turned on.

I tried searching this issue in the forums but couldn't find a similar issue. Some suggested procedures where the battery needs to be removed and re-inserted, however my battery is not removable. Please let me know if someone has the solution without battery removal.