MacBook Pro goes into boot chime loop when the battery is plugged

Hi all, my macbook suffers from a rather strange problem.

One time after a full charge of the battery it showed the “No battery“ sign, and I naturally plugged it to the charger . I left it for a good 20/25 mins to get some power , but once i pressed the power button it went into a rather strange startup chime loop where the chime repeats itself forever. At first i thought i had to reset the NVRAM, so i did it, no success, after that i tried every other possible way of recovering a dead Macbook without opening it /PRAM Reset,Safe mode, SMC Reset, etc./. The only strange thing is that i managed to boot the login screen after a NVRAM reset once, typed my password and the loading bar stucked to the middle. It did this every time i tried resetting the NVRAM. I read through every thread here, and basically all of the internet.

However i managed to open the back panel and after i plugged out the battery to make the manual SMC reset, i plugged the charger but forgot to plug the battery back and the laptop booted completely normally /it felt slower because every MBP downclocks the CPU when the battery is unplugged/.

I read somewhere that the EFI Flash Memory might cause this issue, or the SMC chip, but i still cant be 100% sure.

It’s the first time something like this happened to my laptop, 2 weeks ago I went for a thermal paste change and dust cleaning at a local service , but it has been workin fine until this problem occured. Brought my laptop there after this problem occured, and they couldn’t even diagnose the problem and im kinda left without much options.

If someone here has encountered this problem and probably found the solution i would be grateful to hear it.

*EDIT*: Adding a screen shotfrom CoconutBattery by Dan’s request, kinda pointless because the battery is unplugged and the laptop doesnt get any info from it, anyways here it is: