ROBBE Compact 6S EQ Duo Power Manual De Uso página 52

pressure build-up in the cell during charging and discharging, for which reason a foil
housing is adequate. This cell has rapidly become very popular for model purposes
due to its low weight and high energy density
4. Lithium-Ferum batteries (LiFe) with a nominal voltage of 3.3 Volts. This is the latest
generation of Lithium batteries, also known as A123. This type of cell is likely to find
widespread use in modelling due to the high peak discharge rates and useful energy
density.
CAPACITY DIFFERENCES
If several cells are assembled to form a battery which is then discharged at a fairly high
current, the cells will heat up to different extents, as the cell or cells on the inside are
unable to dissipate excess heat effectively.
This results in changes to the cells' internal resistance, which in turn reduces their disch-
arge capacity. The cell concerned will then be discharged more quickly, with the danger
that it will eventually be discharged below the permissible final discharge voltage of 2.5
Volts.
Considerable differences in capacity can occur when external temperatures are very low.
For example, if a LiPo pack is flown in an electric helicopter, the front cell will be cooled
very effectively by the normal airflow, while the inner cells become significantly warmer.
The colder cell will lose effective capacity, with the danger that it will be discharged below
the permissible final discharge voltage.
To avoid the risk of permanent cell damage we recommend that LiPo cells should only be
discharged down to a final discharge voltage of about 3 Volts. It is also essential to ensu-
re that the cells are charged up to the same level next time the pack is recharged.
Charging parallel-wired cells does not present problems, as the total charge current is dis-
tributed to the individual cells according to their voltage.
We accept absolutely no liability for damage caused by incorrect or incompetent
handling of these cells. Please be sure to read and observe the Safety Notes.
Temperature differences always occur during the discharge process, as the outer cells are
always cooled more effectively than the inner ones. The effect of this, combined with nor-
mal manufacturing tolerances, is a constant tendency for series-wired Lithium-Polymer
cells to drift apart in their state of charge. After several discharge / charge cycles indivi-
dual cells inevitably exhibit differences in voltage.
Operating instructions
Compact 6S EQ Duo Power
24
Order No.
8506