Owning a couple of batteries is not a luxury that one should be thinking too much about so the solution to this problem is rather simple.
However, and please don’t take this the wrong way, you are saying that you are displeased with shooting for 3-4 hours and yielding 150 pictures as a result.
I understand that nowadays the trend is shooting a lot first and go through thousands of shots to chose from after but there has to be a way to think more and shoot less.
Seriously, when I was very young I was working for a press bureau ( although I was never a real press photographer), and they gave us one roll of +/- 36 shots, we were cutting them to size from large rolls ourselves per event.
An we were expected to bring back the beef.
However, I understand that you may be into weddings.
Those are notorious for asking a lot from the photographer covering the event, but two batteries should be sufficient and in any event (pun) buy 3...!
the popular expression wishful thinking is an oxymoron!
Please remove the obnoxious tapatalk signature, it adds nothing to anyone’s contribution and it is only a sneaky way used by tapatalk to push their product by polluting each forum participant with promoting their products. They don’t even pay you for this! Nobody really wants to know about the brand and type of your phone or the program that you use to post on the forum.