All I know is the battery performances on my 350/650/T1 improved incrementally using a "never (well, very rarely) switch off, always charge on 1-2 at most, leave overnight, and use a wall-charger" regime.
Obviously it doesn't keep on getting better, but they all last a month, sometimes more, and much more on the 650 that doesn't get used as much as the other two.
I suppose the battery just gets trained ?
And none have died yet ....fingies x'd.
