Question Yellow light (NOT ORANGE LIGHT) when charging (PLEASE READ FULL DESCRIPTION)

[LTL428]

So everything was going fine the other day. No issues whatsoever. Then today, I come home and check my laptop. It was charging the whole time I was gone, so I expected a full battery. So I turned it on. And for some reason I get the 8 orange flashes (Indicating that the laptop's battery level is too low to operate). This has happened multiple times before ever since I've upgraded to Windows 10. I try a few techniques that always seem to work. Nothing. So then I plug my cable out, and then back in. Now, I get something. I get a green light (Which indicates that the laptop is on) for a fraction of a second, and then a yellow light (Yes, a yellow light. Not an orange light, or a green light, a yellow light). Does anyone know why this may be happening?

Laptop model: HP elitebook 8470p
Techniques I tried: reinstalling battery, plugging the cable in and out, leaving it unplugged for a long time, leaving it plugged in for a long time

 

[ex_bubblehead]

Sounds like a battery that's reached end of life.

Exactly how old is the battery? Check for a date of manufacture as that's when the clock starts.

 

[LTL428]

Sounds like a battery that's reached end of life.

Exactly how old is the battery? Check for a date of manufacture as that's when the clock starts.

I don't know how old it is and can't check because it was not the original battery that came with the laptop. I bought it because the battery the originally came with the laptop was in very poor condition. It was not confirmed to be pulled from an HP elitebook 2740p but it said that the battery was compatible with the laptop.

Though you could still very much be right as it isn't an original HP battery.
The only thing I found that could be relevant to the manufactured date of the laptop was this:

Standard: GB 3 1 2 4 1 - 2 0 1 4
Which could mean that it was manufactured at that time but again I'm not completely sure.
If that's the actual date of the battery then it wouldn't make sense of it being End of Life because the laptop was released in 2010, so the battery is relatively "new". If you or anyone else has any ideas make sure to let me know.

 

[LTL428]

Update: The battery isn't the problem. It's the laptop itself. When I unplug the battery and try turning it on with the laptop plugged into a power source, it does the same thing. AKA 8 orange flashes. Also, if the battery is out, when I plug the laptop in it will do the green and yellow flash. The same goes for doing the opposite.

 

[ex_bubblehead]

Assuming the battery was manufactured in 2014 then it is well past replacement time. Batteries are typically good for only 2-3 years at most when properly cared for. This one is 8 years old. Replace it.

As to the still blinking LED, have you tried another HP charger for that model? They are also known to fail. Failing that it's either off to be repaired (if possible) or replacement. Those are your only options.