I have too many batteries and it's time to let this one go.
It comes with a charger.
The cell may be going bad as it doesn't hold the charge as well as new units. Quantum can replace the cell for $80 or so I believe (I'm not sure about the price, you'd have to check with Quantum to be sure).
The battery works fine though, and if you don't shoot at full power it should last the whole wedding no problems however. I just used it at my last wedding and it didn't die, so the cell is not a toast just yet.
I'm selling for $300 shipped to CONUSA.
It sells for $549 new at B&H so even if you decide to replace the cell it still should save $150-$170 over the new one.