This is something I’ve noticed with /e/OS that it does not show a low battery notification (when it reaches 5%) like stock Android. Many times, I just don’t pay attention to the battery percentage and the phone just ends up shutting down, which is so annoying.
Any fix for this?
I am surprised a bit, where did you get the idea of 5% warning? I had stock android phone before and it used to give 20% and 10% warnings, my Murena e/OS does exactly the same! 20% and 10% warnings work perfectly fine offering to switch battery saver on…
I don’t think there is any problem to resolve really 
Something you may perceive as not a problem may be a problem for other people. That’s why open source freedom is a thing.
Anyway, my bad, this was Samsung. In this case when it would reach 5% the phone would dim so you would be instantly aware its about to shut down.
It seems like you can configure this as well on Samsung:
Well done, You answered your own question and resolved the mystery of 5% 
Please refrain from posting useless comments that don’t contribute anything to the discussion.
I think you are right, I am going to leave this topic behind before next thing in here is 1% battery low warning request… 