Replacement battery from iFixit for iPhone 4S has short lifespan
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.
Is this a good question?