[Elecraft] Li-ion/Li-poly question

[David A. Belsley]

A question relating to Lithium-ion and Lithium-poly batteries:

Facts that circulate about these batteries include two that seem 
somewhat at odds with one another.  First, it is apparently not good to 
store these batteries at full charge.  Battery life can be extended if 
they are stored more nearly at 40% charge.  Second, there are limited 
numbers of charge cycles, say, in the 300-500 range.  This figure, of 
course, can vary greatly, but, without doubt, there are limits.  In any 
event, battery life can be extended by minimizing the number of charge 
cycles.

The second fact would suggest that, whenever possible, it is better to 
reduce cycles by keeping the battery under a charger.  But, at the same 
time, if this is done for prolonged periods, it would be like storing 
the battery under full charge, which, according to the first fact, is 
problematic.  Here, then, are two conflicting acts that reduce battery 
life, causing charging cycles, and storing with full charge.

Does anyone have good information about which of these is the lesser of 
evils?

thanks,

dave belsley, w1euy