Depends on the modern smartphone, I have a Xiaomi Redmi Note 4 and it has amazingly good battery life (much better than my company-supplied Samsung Galaxy S8),

Depends on the modern smartphone, I have a Xiaomi Redmi Note 4 and it has amazingly good battery life (much better than my company-supplied Samsung Galaxy S8), I can sometimes go two days without charging. They do cheat with ridiculous background app-killing "features" though (I've tweaked it to my liking and now prefer it)