The latest Niantic update made a few performance changes for the Pokemon Go application. It is meant to improve stability. Although, the update was surely able to address this issue it somehow gave birth also to a couple of problems. The major problems that were encountered with this performance update were related to the increase of memory leaks and drainage of phone battery. These problems plague trainers who are iPhone users and maybe some Android users also.
It looks like many trainers surely had a hard time having their phone's battery stable, just to avoid having their phone die for just a few hours. Though, this is not something new when it comes to Pokemon Go, but it is just truly worse. According to a Reddit post, there were also reported crash issues observed for the game. It has now become more often now as compared to how it was before. There are many stories that can be seen on reddit from users who also experienced related problems.
This performance update is not that compulsory yet. Therefore, it has been suggested to players to avoid this update as of now. Extra battery storage cannot also help with this problem, although this is just one key alternate tactic that is meant for trainers. It is for the purpose of having them to stay out longer while playing the game without draining off their batteries, as reported by Otaku Kart.
The normal drainage of the battery is around one percent for every 1.5 minutes, but this could vary among users. It can be increased or decreased due to this update. This memory leaks issue has since been existing even from the beginning of the game, and it seems that it only got worse. Niantic should hopefully be able to fix this problem as soon as possible.