It's fine to work sometime on battery. Except, after 5 hours, marginal utility decreases, and 8 hours it goes to zero. Why would I need more than one day?
because you're a "dev" who makes web pages for a company that can't afford an oracle license. and your office is a starbucks. but you want to call your little toy a pro, because to non-programmers, you make missle guidance systems. well not you. but the other few people on this thread.