That's exactly right Russ. Although the total life of Li-ions isn't yet known reliably under each condition due to lack of time experience, some characteristics are well known and understood. The Li-ion electrolytes are best kept topped up as full as possible at all times and then they have the longest chemical life. The deeper they are discharged, the greater the chemical stress, and on Li-ions this very markedly reduces the life. The main reason for that is the very high density of the electrolyte that's necessary to give the high capacity, this impeding the flow of current through it. The more and the deeper the current is forced through in either direction, the more the electrolyte suffers.
New research such as Lithium Polymer is now focussed away from that, using lower physical density electrolyte, with the high charge density maintained by use of smaller particulates having the same ion handling capability but taking up less physical space.
Lithium Cobalt batteries die by gradually increased internal resistance making it more and more difficult for the current to get in and out, the manganese based batteries that eZee supplies lose their capacity equally but by chemical decomposition instead. The rate of capacity loss in all Li-ion cases is mainly related to that depth of discharging and temperature.
The total range of capacity loss is huge, in an ideal case the capacity loss can be just 2% in one year, though an electric biker would find it impossible to provide such ideal conditions. The worst case means a loss of up to 35% in one year, i.e. a 15 mile range becoming less than 10 miles.
Finally, manufacturers have indicated a charge cycles figure for Li-ion of 300 to 500, but as with all battery types, this charge cycle figure is notional and not a reliable indicator. Most feel multi cell traction Li-ions are good for about two years use on average.
