Hello Jholmesford,
* Accessory may not supporting to your device
As you got high capacity (3.2Ah) battery it required original charging accessory to use otherwise it will take long time to get fully charge. When you plug the original charger phone will automatically change the charging mode to rapid charging and phone will be charge around 80% withing 1 hr and 30 Mins. if you don't have original charger you may required to use 5V 2A Charger.
* USB port
Check whether any sign of damage or corroded in micro USB port. if it is you can clean the port
* Power source
Check in the setting whether you phone identify the power source, Connect phone to charger Path: Setting - About phone - Status- Battery (Charging should be AC) anyhow it shows as USB there is something wrong with your USB port or Power IC
Hope this answer help you to troubleshoot the fault.