IPhone battery & charger

My battery goes down too quick if the brightness is half or over, and it keeps vibrating on charge and randomly sais this accessory can't charge it

You need a new charger if its unsupported and the battery life is terrible on iPhones nothing you can do about it I'm afraid I think they have this battery thing power by Duracell where you uh it in your phone and it gives it some life

Turn off your bluetooth under setting
double tap your home button and see how many apps are running in the background.

hold your finger down onto one of them and begin hitting the x on each one in order to close them all.
Also change your preferences to check mail manually only. And in the notification center settings, turn them off. And in the future do not allow push notifications.

main goal is to limit the back ground activity of you iPhone.you'll see results.

you'll have to get a new charger. I've purchased several (maybe 10+) cables for my iphone4 and iPad and if it's not straight from apple, I get that error message. And apple's cables never last more than a year due to wear and tear.

You don't say how old the iPhone is? A properly maintained iPhone battery is designed to retain up to 80% of its original capacity at 400 full charge and discharge cycles.

You can get the battery replaced, but this needs to be done by Apple (book an appointment at an Apple store near to you).

Charging your iPhone while in certain carrying cases may generate excess heat, which can affect battery capacity. If you notice that your iPhone gets hot when you charge it, take it out of its case first.

For proper maintenance of a lithium-based battery, it's important to keep the electrons in it moving occasionally. Be sure to go through at least one charge cycle per month (charging the battery to 100% and then completely running it down).

Always make sure your iPhone has the latest software from Apple, as engineers may find new ways to optimise battery performance.