Voltage State of Charge
Discharging and storage really go hand in hand. For NiCd packs, you should completely discharge them, to 0.9v per cell, before you store them NiMH packs should be stored with roughly a 50% charge in them for best performance. And before you charge a NiMH pack for the first time in the day, simply drain the pack completely on a discharger or in the model and you are then ready to charge the pack for use throughout the day.
LiPo batteries are completely different when it comes to discharging and storage. Depending on the output voltage of your pack, you should only discharge your pack so far. For example, during use, a 7.4V LiPo battery (also known as a “2 series” or “2S” pack) should never be discharged below 6.0 volts under load (3.0v per cell). For storage of 2 weeks or more, LiPo packs should be stored at approximately 3.8v per cell to prevent overdischarge or imbalance from developing among series cells in the packs due to differing levels of each cell’s self-discharge rate. In the case of a 2S 7.4v pack, the pack should always be stored at 7.6v. You should also store your LiPo batteries in a fireproof container or cabinet and never store your LiPo, or any other battery for that matter, in the model itself.