Revive Li-Ion Battery White MacBook (2006)
If a lithium ion battery is drained and left to sit for an extended period of time uncharged, it can go into a "sleep" state that does not enable a recharge by standard charging methods. 
I found this info at http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

"Li-ion should never be discharged too low, and there are several safeguards to prevent this from happening. The equipment cuts off when the battery discharges to about 3.0V/cell, stopping the current flow. If the discharge continues to about 2.70V/cell or lower, the battery’s protection circuit puts the battery into a sleep mode. This renders the pack unserviceable and a recharge with most chargers is not possible. To prevent a battery from falling asleep, apply a partial charge before a long storage period."