Power Supply
Page 17
© 2016 Valeport Ltd
5. Power Supply
5.1. Changing Batteries
The 8 “C” cells are housed in the battery compartment in the bottom of the CDU. Access is gained
by unscrewing the central retaining screw and pulling out the end cap and pcb assembly. The cells
can then be removed. When putting in new cells, be careful to ensure they are inserted the correct
way. Labels are located in the compartment to indicate the correct way [note the large springs
touch the -ve end on each cell, small springs the +ve end].
5.2. Battery Life
The current consumption of the units is as follows [all measured at 10vDC]:
Backlight On
Backlight Off
Standby
92 mA
33 mA
Run
229 mA
171 mA
The battery life, based on good quality alkaline cells, operating at approximately 15 degC [note
performance can reduce with low temperatures] and working on a duty cycle of 5 minutes On / 1
minute Standby is as follows:
Elapsed
Time
Elapsed time
Low Battery to
Stop
Actual On
Time
On Time LB
to Stop
% Duration to
Low Battery
(Hours)
(Hours)
(Hours)
(Hours)
Backlight off
3.50
2.91
91%
Duration to low battery
34.00
28.33
Duration to stop
37.50
31.25
Backlight on
7.00
5.82
75%
Duration to low battery
20.50
17.08
Duration to stop
27.50
22.92
If the unit is left in standby, and if no button has been pressed for 5 minutes, the beeper emits 5
beeps to remind the user that the unit is still switched on. This feature does not operate when the
CDU is connected to a PC for communications such as downloading data.
