When I plugged my phone into the OEM charger this afternoon, it was at 8%.  A few hours later, after what has normally been sufficient time to fully charge it, it was down to 7%.  I've tried multiple chargers that are known to work and with multiple outlets.  I've turned it off and tried to charge it.  Nothing has worked.  It's now down to 3%.

This phone is 9 months old.  I've never had any problem charging it until today.

What else can I do here?