Is there a way to change the iOS low battery warning to pop up at 25%? I have a jailbroken iPhone 4 running 7.1.2., I tried using the cydia tweak lowpowerbanner but I don't think it worked. So if you could suggest another tweak that'd be great.
I think that a tweak named "Power Informer" is what you are looking for. 
Step by step instructions by WonderHowTo on this link.