Battery Suddenly Not Recognised in my 2013 11" MacBook Air?

Hi all,

A bit of a head-scratcher which i've been trying to troubleshoot for the past week. Hopefully someone here on the forum can provide some guidance.

The Context:

About July last year a cousin of mine gave me her old 2013 11 Inch MacBook Air because (in her words) it has stopped working and I'm known in the family to tinker with laptops (admittedly, she didn't really look after it).

Anyway, I got it home and quickly realised that the only issue is the magsafe connector is a bit worn out. By jiggling the connector around I could easily get the orange/green indicator light to show up, the MBA would charge and otherwise operate normally.

I went ahead and purchased/installed a replacement battery from iFixit seeing that the OG battery had over 1000 cycles. I then installed macOS Ventura (and eventually Sonoma) using OpenCore Legacy patcher which all worked pretty well.

For the past half year i've been using this little machine as my Discord and Spotify hub to great affect.

The Problem:

About a week ago I noticed that the Laptop would not power on unless the charger was connected. The magsafe indicator light shows a solid orange light. If the laptop is on and I disconnect the charger, it instantly dies.

If I reconnect the charger and hit the power button it seems to 'resume' rather than restart (even if the laptop was in the middle of booting).

The Investigation:

To date I have tried:

• Multiple SMC and PRAM resets.
• Disconnected the battery connector and left it for 24 hours before reconnecting.
• Tried a different Magsafe Charger
• Wiped and performed a clean reinstall of the latest Officially supported OS (Big Sur).

The weird thing is that if I power the laptop on and remove the connector AFTER the startup chime then it will go most of the way through the boot up process before it shuts off. I've even performed an Apple Diagnostic test (whilst running on battery power) where I'll get an error code PPT001 "The Battery was not Detected" (this whilst the machine was UNPLUGGED from its charger). So clearly the battery works in some capacity?

The System Information app in Big Sur only shows zero values under Battery Information.

I've Included a collection of photos at the end of this question.

The Question:

I'm unsure where to go from here? Is this clearly a logic board issue? Or is it a battery issue? Are there other tests I can try? Is the battery stubbornly stuck in a low power state? Something else entirely?

I am willing to purchase a new battery for this machine but if this turns out to be a logic board issue then repair would likely be expensive (I would need to send it away - that sort of repair is way outside of my experience level), likely resulting in me throwing it away.