No Battery Detected and yet MacBook Pro runs on it!

AndyPro720 · May 6, 2021

I am primarily a windows user, so bear with any errors on my end.
I recently upgraded my friend's mbp mid 2012 with 8GB of RAM and swapped out the HDD for a SSD. I reinstalled the OS using the internet recovery method and didn't face any issues except that the laptop never started on battery. For the installation I kept it plugged to the charger, and planned to deal with the battery later. The charger light had been bright green all along.

After installing the OS, the battery still didn't show up, and checking the system information(power) revealed- battery connected: No. Unplugging the charger doesn't shut the mb down but instead puts it on a hibernate equivalent state with sleep light blinking.

Here's what I tried:
I tried checking both the connectors, plugged them back in.
Did PRAM and SMC reset multiple times, with and without charger and battery plugged in.(Different versions on the web)
Checked the pins next to the battery connector and they receive the correct voltage.

Scouring the internet for possible solutions.

The next morning I tried to start the mbp on battery and confirming the earlier notion that the battery was working, it started up, only without showing up anywhere(system pref still reads no). I tried updating the OS to latest fix and yet no avail. Also, I did ask my friend if he came across any battery depletion warnings earlier, to which he mentioned he never did.

This is my first time posting on these forums, and I would sincerely appreciative any help.

Flannelist · May 6, 2021

Had to do a little research on this, but. That model has some battery indicator lights on the side, if you push the button do the lights work/show accurate battery levels? If not, I would try reseating that connector, it's the one directly to the right of the battery connector.

AndyPro720 · May 7, 2021

18 hours ago, Flannelist said:

Had to do a little research on this, but. That model has some battery indicator lights on the side, if you push the button do the lights work/show accurate battery levels? If not, I would try reseating that connector, it's the one directly to the right of the battery connector.

I did that, it seems stuck.
After some more research yesterday I'm narrowing it down to something on the data line connected near the battery being fried([probably smc chip). Seems like while unplugging the battery during the upgrade I managed to short the data and power line(they are right beside and using the flathead driver to pry out the battery must've done so) Its still inconclusive though, let's see.

Flannelist · May 7, 2021

3 hours ago, AndyPro720 said:

I did that, it seems stuck.
After some more research yesterday I'm narrowing it down to something on the data line connected near the battery being fried([probably smc chip). Seems like while unplugging the battery during the upgrade I managed to short the data and power line(they are right beside and using the flathead driver to pry out the battery must've done so) Its still inconclusive though, let's see.

Ooof. Yeah. That could do it. I suppose it's not the worst thing ever, I've seen things get shorted super dramatically in the course of repair. Like visible sparks and burning electronics smell level of shorting. Which is part of why I avoid using anything metal on/near a machine until power is disconnected. Because I've been present for other people learning that the hard way. But those battery connectors can be a giant pain to pry out. At least it wasn't anything system critical, it's just inconvenient. Good luck in any case.