Third party and continuously charging.
Third party turned out the better choice for me. But that is not a guarantee.
As of the charging question I came across an elaborate article discussing various battery types and
charging conditions. For lithium-ion batteries maximum life was reached at a 40% charge and storing
them cool (not frozen). So when foreseeable you do not need the battery you best could take it out at
40% charged. But then again you are not benefiting the built-in UPS that a battery is too in case of a
power-outage or someone tripping over the power-cord. What a dilemma ;and 2013 has just begun.
Average lifespan of a Li-ion is 2 to 3 years. Any time longer is a real bonus and always will come with
a reduced remaining capacity. And speaking of capacity: replacement batteries sometimes come with
different initial capacity. So when running on battery is not your main concern go for a cheaper one
even if it means less capacity.
With Kind Regard,