I have a Turnigy 2s 5200 mah 30c hard case lipo that I bought less than a month ago, have ran at most 6 times, and now one of the cells appears to be bad. When I hook up the balance lead, and set the charger to balance charge, one of the cells will barely take charge, but the other one does. So what happens is one cell gets to 4.2, but the other one can't really make it past 4V. The charger is set to cut off after 2 hours regardless if it's done or not. I've set this to cycle a couple of times, so in 4 hours it's not able to bring this other cell up to 4.2. I've tried discharging and then charging again, and that doesn't seem to work. The pack doesn't look puffed as far as I can tell, but certainly something is off.

Does anyone have any suggestions before I soak it in saltwater etc?