So @wiewiec , you and me we have 3.65 Enzo on the PS Vitas with the drain issue.. Maybe its related to 3.65?
No 100% sure that I had same problems on 3.60. I even tried first 3.65 hack to make sure that it was not related to 3.60. This hack for some time bloced possiblility to even donwgrade etc. since there was no h-encore etc. then. On my previous testings I updated plugins that could give some problems for example I had old SD2Vita plugin - updated it to https://github.com/CelesteBlue-dev/PSVita-StorageMgr/releases. I also updated Enso to https://github.com/SKGleba/enso_ex. Last chance before I buy any battery is found my few batteries that I bought when I noticed this problem few years back.
I also could try wipe it again as @GraveViolento mentioned, but probably I should reinstall sim card reader... Shame that $ony gives us this shitty battery bar without option to have it in % :/
Also when I tried to find some help I noticed that on VITAident GUI on section about battery cycle count was always fixed little around 110 - same was even when I changed batteries - it was little bit odd for me (now after checking cycle count is 113).