Chosen Solution
I recently replace the battery on my mid 2012 MBP and when I leave the system closed in a sleep status over night. I’ll come back to a dead laptop in the morning and I’ll have to power it on. The laptop will power on with a 50% charge. Once is a fluke, twice…? I think there might be something wrong with the battery. I got the battery off IFIXIT
I think you got another dud of a battery. Let’s try SMC and PRAM resets just in case the battery isn’t the problem. How to reset the SMC, PRAM and NVRAM on a Mac Laptop
