Optimizing for lifespan of LENOVO NC140BW1-2S1P battery

The main enemies of LENOVO NC140BW1-2S1P battery longevity are age, the number of charge cycles, amount of time at full charge, and high temperature. 
For maximum lifespan if you rarely use the battery, set Custom charge thresholds to start charging at 40% capacity and stop at 50%, and keep the ThinkPad cool. The thresholds can be adjusted in the Battery Maintenance settings of the Lenovo Power Manager. 
If you do use your battery somewhat frequently, set the start threshold at say 85% and stop at 90%. This will still give a good lifespan benefit over keeping it charged to 100%. 
The simplest way to optimize for battery lifespan is to select Automatic in the Power Manager Battery Maintenance settings, and let it manage your battery charge thresholds for you.

LENOVO NC140BW1-2S1P battery

Brand new LENOVO NC140BW1-2S1P 7.6V 4140mAh laptop batteries
Voltage: 7.6V
Capacity: 4140mAh (31.05Wh)
Battery cells: 2-cell
Chemical: Li-ion
Battery Color: Black
Condition: new original battery
Warranty: 9 months

Product link: http://www.storebattery.co.nz/lenovo-nc140bw1-2s1p-7.6v-4140mah-laptop-battery-store-for-new-zealand-p-192898.html