Since many phones have all the necessary apps that we like and we have already , those apps consume so much power that it makes our batteries drain out fast and all. So I suggest that you always watch out your battery for example in charging.. make it a point to charge your phone before it drains, second, don't overcharge since this is the best way for you to make your battery healthy and also safe to use. Close all apps that you are not using. Lower the volume and the brightness of your phone... These are some ways in order for you battery to be long lasting and also safe to use. I also know that the old phones have long lasting batteries since it doesn't have apps yet that is battery consuming. So if you're up with that, those are really the phones that has long life batteries.