To get maximum use out of your Sony Vaio Vgn-nw31ef/w battery there are a few things to keep in mind:

• Avoid frequent full discharges because this puts additional strain on the Sony Vaio Vgn-nw31ef/w battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.
• The Sony Vaio Vgn-nw31ef/w replacement battery with fuel gauge should be calibrated by applying a deliberate full discharge once every 30 charges. Running the pack down in the equipment does this. If ignored, the fuel gauge will become increasingly less accurate and in some cases cut off the device prematurely.
• Keep the lithium-ion battery cool. Avoid a hot car. For prolonged storage, keep the Sony Vaio Vgn-nw31ef/w battery at a 40% charge level.
• Consider removing the Sony Vaio Vgn-nw31ef/w replacement battery from a laptop when running on fixed power. (Some laptop manufacturers are concerned about dust and moisture accumulating inside the battery casing.)
• If you have a spare lithium-ion battery, use one to the fullest and keep the other cool by placing it in the refrigerator. Do not freeze the battery. For best results, store the brand new Sony Vaio Vgn-nw31ef/w battery at 40% state-of-charge.