MacBook Pro 13" (late 2013) not registering true battery charge. Help please?

Hello!

In short:

My MacBook Pro has a new battery (after letting it drain and stay dead for too long), but even after a multiple SMC resets it kept lying about the battery charge. Now I can’t get it to turn on. It desperately needs updating but I can’t do that if it keeps sleeping and then won’t turn on.

What I can remember trying:

It did turn on with the new battery and said 9% which dropped very quickly to 1% and said plugged in but not charging, though when I looked a few minutes later it was on 3% so I thought right, it needs charging to 100% anyway so I’ll see if it charges anyway. I closed it and left it plugged in for a good 24 hours before I opened it again.

It was swapping between 3/2/1% so I tried to restart it and it got stuck on the apple loading screen. I turned it off, reset smc, turned it on and it said 63% but as I logged it and it showed the loading bar it was moving slowly and the screen dimmed like it was about to sleep. No keys or trackpad movement would light it up fully and it went to sleep. I pressed power and it came back up to the log in screen. Tried to log in and it worked. 57% still apparently with the charger plugged in but not charging and no apps using significant battery.

I tried resetting smc again, it turned on (I think this time was Safe Mode) but still saying not charging. Battery was around 57 still… It desperately needs updating and the bubble prompted that there was an update ready so I clicked it and it was searching for updates for long enough to let the screen dim again. No keys woke it up and it went to sleep.

I woke it up and logged again. It was still searching for an update so I closed it and reopened it. Then it said battery was 43% and photos was using significant battery, even though photos wasn’t open. It dropped to 27% without any gradual decline, then all the way to 6%. I opened photos and closed it from the drop down. It still said it was using significant battery.

By then it had found an update. I clicked to start it and it gave me the colour wheel for a while. Then I noticed battery had jumped back up to 19%, then 46% (ish - I can’t remember every single number exactly) but still photos was using battery, so I thought maybe it was trying to download/upload to iCloud and decided to attempt to uncheck photos from iCloud settings. It gave me the colour wheel too. Eventually dimmed, wouldn’t light up to clicks or keys and then slept.

I left it for the night, plugged in, and this morning I turned it on at 3% which dropped through numbers to 0% before it could even load after login. Now it won’t turn on in any mode. 🙃

It so desperately needs updating but I can’t do that if it won’t turn on. I know the actual battery is fine because this is the THIRD battery I’ve tried. I got the first replaced because they thought it must be faulty but the second wouldn’t charge either. I ordered from another place and this is the same.

I got this MacBook Pro from a friend of mine when she was upgrading and, considering it’s a decade old, it’s been surprisingly fantastic. SO much faster and crashes WAY less often than any windows laptop I’ve got. But now I’m sick of it throwing a tantrum.

Does anyone know how I can force it to turn on and update or reset setting another way? It’s OLD so it seems crazy to pay apple repair costs that are =/> the Mac’s value now.