I don't know the 8080 battery or the charger but I have done some Li-ion
charger design and looked at the Li-ion literature. So I can make some
general comments.
Look at the Li-ion battery case or spec sheet and it should say what the
capaciy is in Amp hours (Ah). In general they should not be charged faster than
the so called "C" rate. That is if the battery capacity is rated at say C=2.5Ah
then they should take at least 2.5hours to charge. Anything faster is likely to
reduce life by reducing capacity a tiny bit each cycle. There are so called
pulse chargers that claim to be able to charger faster than this but there does
not seem to be enough experience to really understand how well these do in
preserving capacity in actual field use. Accelerated charging tends to
increase battery voltage at end of charge and this increases the rate at which
active Li material is irreversibly converted to an unavailable form. This
reduces capacity a little bit each cycle reducing the battery cycle life, as
capacity drops more rapidly than normal over many cycles. Basically the cells
are very sensitive to voltage near end of charge. This means yo
u can
increase cycle life by using a slightly reduced voltage at the cost of reduced
energy per cycle. The end of charge volage per cell needs to be controlled to
within 50mV of the ideal value. The ideal value being chosen based on the
trade-off of cycle life versus capacity. If you want to increase cycle life
you can slightly undercharge the cells by say putting the charger on a timer to
cut it off early. Occasionally do a full charge to balance cells. A little
known fact is the cells do better if stored partially discharged rather than
fully charged. So if you are not going to use them for a while don't fully
charge them before storing them.
Regards,
Tim Hughes
==============================================
List usage info: http://www.zuikoholic.com
List nannies: olympusadmin@xxxxxxxxxx
==============================================
|