Well if you have your voting power at 100%, you can make 10 full power upvotes and start at 100% the next day. So if you want to make more than 10 votes a day, you might want to consider using less power or if you are going for a vacation and can't vote, vote more than 10 times a day with full power to not waste any power. 

So if you give more than 10 full power votes a day, you will eventually run to 0% voting power if you don't let it recover. See https://steemworld.org/@ohicklin for info about how much power you have left and how long it will take to get back up to 100%