9
1.) The
volts per cel
l (
4.2V/C
) determine the maximum capacity you put into the battery. The
default is 4.2 volts per cell commonly used by Lithium Polymer batteries. This is typically the
maximum charge that is recommended by LiPo battery manufacturers. The Xtrema allows you to
alter this rate in the
SETUP MENU. It is very important to pay attention to this number since
M1 cells must be charged no more than 3.6 volts per cell.
When charging Li Polymer cells, you
can make this number smaller to provide a more conservative charge. Charging conservatively
prolongs the life of the battery at the expense of reducing the run time per flight by a small percent.
2.) The max
temperature cutoff
(
104F
) is also shown in this final display before charging. This
too can be adjusted in the SETUP MENU. The default is 104°F but this temperature is best
adjusted to be only a few degrees above the starting battery temperature.
3.) The
max safety timer
(
120abt
) is also shown in this final display before charging. The
default abort time is 120 minutes but you can and should make this time longer in case you charge
your battery at a conservative CURRENT setting. For example charging a 2000 mah battery at
1000 ma will take twice as long to charge than if you were charging it at 2000 ma. This is a very
conservative charge rate that should put a minimal stress on the battery while charging however,
you may want to consider changing the max safety timer to say 150- 240 minutes to allow the
extra charge time.
Note:
After the charging has started, if you hit any key to abort the
ABORTED!
Status will show and the unit will stop charging. Hit any key again to go to menu.
Note:
After the charge cycle has ended the Xtrema will beep (if not silenced) to signify the
end of charge. The beeping will continue until you hit the joystick button in any direction. This will
shut off the beeping but will leave the display intact so that you can observe the terminating values
of the recent charge. You may also stop the beeping by simply removing the battery from the
charger. The display will show the final result until you push the joystick as described above.
(Remind me beep mode is assumed above)
Note:
In order to extend the life of the fan, the Xtrema is programmed to turn the FAN ON
only when charging a battery with 50 watts or more power. Therefore you may not hear the fan
running when charging small batteries.
Charge Display
–
During a charge you will see the following display
Li03 cell Charg CC
In:13.80V Bat: 11.12V
Tmp: 72F Cur: 1200mA
00:30:49 C: 605mah
Number of Cells
expected
ERROR / STATUS
( see section 8)
Actual Battery
Voltage while
charging
Actual Battery
Current while
charging
Cumulative
Charge dumped
into cell
Power Input
Voltage
Temperature probe
display.
(displays none if
disconnected)
Total time since
start of charge