Chosen Solution
I replaced the battery in an iPhone 4S using an iFixit replacement around April 2015. And it worked decently for a while although it never lasted more than a day and a half when unplugged from the charging cable, even with no usage of the iPhone (it’s a backup device that usually remains constantly charging except for the occasional field test). But that replaced battery no longer holds a charge beyond 4 hours from a fully-charged state as early as June 2016 (a lifespan of just over a year). Is this normal? The iPhone 4S is undamaged–no drops, no water damage, nothing. It’s fully working and nearly pristine. It’s just that battery needs to be charged every 4 hours now. Also, all background updates and refreshes are disabled in iOS for this device.
Probably just a bad battery. Overall, I have been happy with my iFixit batteries (small sample size though) but you always have to remember that we are always buying aftermarket or refurbished parts at some level. Only Apple has truly original parts.
