I have a black Macbook, aprox 15 months old. Last year when it was still under warranty I had it repaired as it had the common problem of randomy shutting down. It was fixed and all was good until recently when it starts turning off automatically when the charger is not connected. I have the battery update installed and have tried numerous SMC resets with no luck. Coconut battery is reporting 84% battery capacity with 149 loadcycles.

Should I replace the battery or send it in again for repairs?