"Wow... that is some pretty low expectation for a device costing many hundreds of dollars."
Just for you Paikinator: http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batterie s
"Eleven new Li-ion were tested on a Cadex C7400 battery analyzer. All packs started at a capacity of 88–94% and decreased to 73–84% after 250 full discharge cycles."
"Although a battery should deliver 100 percent capacity during the first year of service, it is common to see lower than specified capacities, and shelf life may contribute to this loss."
"Similar to a mechanical device that wears out faster with heavy use, the depth of discharge (DoD) determines the cycle count of the battery. The smaller the discharge (low DoD), the longer the battery will last. If at all possible, avoid full discharges and charge the battery more often between uses."
Essentially, the DoD determined the Li-Ion life. The more you discharge below 30%, the faster the discharge, the more STRESS - you will see the word STRESS in hundreds of phrases, written by the PhD gurus. Any rapid charge or discharge causes stress. Every cell dropping fast below 30% looses its reactive capacity to charge exponentially faster. So that battery heads for an early life. As some cells begin dying, so does the erratic behaviour.
of note, the industrial average is 300-500 cycles. However, it nowhere says 300-500 FULL 100% DOD discharges. So someone draining his battery from 90-40%, and recharging twice as much, will bet more than x2 the life of an user with a DOD of 100-0%.
