Defective alternator, dead cell in battery, something on pulling power from the battery when the vehicle is idle, corroded battery cable connections, or loose alternator drive belt.
Maybe your alternator needs replacing.
Sulfation can happen when battery is not fully charged and remains discharged
It could be a faulty battery, If you have bought a new one recently, and it still wont stay charged, its probably your altenator. good luck or it may be the altenater.
Then something is on pulling power from the battery. Any light on the vehicle or any relay that is stuck closed.
Take it to your local auto parts chain store. Most of them will check your battery and alternator for free.
Dead cell in battery or something is on pulling power from the battery. Disconnect the negative battery cable overnight with the battery fully charged (12.6 volts). If the battery is dead the next morning it has a dead cell and needs replacing. If however the battery is still fully charged then a light is on somewhere or a relay is stuck closed.
disconnect the positive lead from the battery with everything off. Then touch it gently to the battery post , if you see a spark there is something drawing current
It might need a new battery.
Don't charge it frquently.
Dead battery
The voltage regulator and or the alternator are bad. You need to have these items checked. Make sure the wiring is in good shape and battery cables are in woking order.
gsxr 750 06 battery wont stay charge