IPhone 4S won't charge

It randomly charges when very low, but otherwise won't charge at all. Tried multiple plugs, cables, hard reset nothing.

Can't get power up past 30% most of the time and it just starts charging when it feels like it.

Often goes below 10% and shuts off on me. That's unusable!

Any ideas or workarounds?

Best,

Dion Hinchcliffe