Hey fourm, sorry for the long read but if anyone is technically savvy with batteries or voltages/electrical components please read! this might not be specific to a Fold but any device may suffer from what my device is suffering from.
I have recently had issues with my Galaxy Fold Z2 and it unexpectedly dropping to 0% charge, the first time this happened yesterday i was in an application and was switching from the larger display into the smaller one, upon closing the display the phone shut down and i wasn't able to get anylife out of the phone except a vibration when holding the power button, but nothing on the screen. I had about 35% battery at the time but all of a sudden it was at 0, after putting it on the charger it spring back into life. Today however i experienced an even worse problem… My battery was around 55% and i was connecting my phone to my cars bluetooth and importing contacts to the cars console, suddenly the battery went from 55% down to 9% instantly! i was shocked and took a screenshot of the battery graph showing its gradual decline from 100% to 55% but not to 9% to highlight the sudden drop, the battery status on the top of the notification bar was showing 9% all of a sudden but the graph wasnt just to actually see the drop! after that drop in battery it only took about a 30 seconds for that 9% of battery to jump down to 1% again in an instant fashion, following this only a few seconds later it shut down.I was thinking it could just be a dodgy battery for whatever reason but after trying to charge my phone after this sudden crash from 55%-9%-Flat i was unable to charge it up. The phone would signify that it was charging but not giving me a percentage, it would show the charging animation (the animation you get when phone is off and charging) but would only last for around 3-5 seconds before shutting off again and showing the charging icon again, and then shutting off again and rinse and repeat on a loop without charging but attempting too and resetting every few seconds! So for about an hour i couldnt get it to boot/charger properly and i almost gave up, but i decided to try a different charger, i was using the 25w supplied charger but i switched to a 15w older one and the phone ran the charge animation again however this time it identified the battery was charged at 55% rather that it not showing any charge level and resetting and trying again as it did before, this time it went right to 55% and from here the phone booted up and is working normally again!
Im really not sure whats wrong, im starting a process to send the phone back but i really wish to know whats wrong with my device and make sure its also covered by consumer law! if anyone has any clue to this strange behaviour please let me know!