Chapter 1 Sept 19999
POWERING THE NAGRA-D II
The NAGRA-D II is a battery operated recorder and is fitted with and internal BP-90 battery pack, of the
BETACAM
TM
style. This internal battery pack must be fitted to the machine at all times, as without the internal
battery the machine will not operate even if connected to the external charger unit, or supply. A fully charged
battery pack under normal circumstances will give approximately 2 hrs of continuous recording. The NAGRA-D II
runs permanently off this internal battery pack, which acts as a buffer, even when connected to the charger.
The NAGRA-D II's ND-CCC3 (#10755) charger unit supplies a 40 mA trickle charge permanently to avoid
reverse-polarisation of the cells in the battery pack. When the battery needs charging the charger is instructed to
supply the 400 mA charge current. The internal battery will only be charged when the machine is in LOAD or
PARK position. The NAGRA-D II communicates with this charger and instructs it on the amount of current to
supply, at any particular time. The status of the internal battery, in terms of residue etc. can be seen at any time
on the LCD display in the MENU mode (see MENU's in chapter 3). The internal battery pack can be removed
from the machine and charged on a normal BETACAM
TM
charger if desired. However if the internal battery is
removed from the machine, then the memory and settings will be lost. A large capacitor will keep the internal
settings for a couple of minutes. The machine will use default (WAKE UP) modes when powered up again. If
settings have been saved in a "Template" (see menus) then these settings will not be lost and can be restored
once a new battery is put into the machine.
NOTE :
When the internal battery is replaced then the battery management system assumes that the
new battery installed is already full and will indicate 100 % in the battery reserve menu. If
however the operator knows that the new battery is only charged to 25, 50, or 75 % this can be
stored in the memory of the machine in the menu mode and the machine will take this pre-set
value into account from the start.
WARNING: The battery pack in the NAGRA-D II is of the Betacam
TM
type fitted with a 2mm DC two pole
connector (positive pole on the external connector) WITHOUT any form of internal electronic
protection or control. Battery packs that are fitted with such internal surveillance electronics
are fitted with a 3 pole connector that is physically too large to be connected inside the
NAGRA-D II.
It is recommended to run the internal battery completely flat from time to time to avoid any
memory effect accumulating in the NiCd.
NOTE:
As the internal battery is always inside the machine the life of the battery is shortened as it is
charged at a temperature of about +40 °C. Meaning that if a full 2 hrs of recording time is
needed on the internal battery then the battery must be replaced with one that has been
externally charged. The effective life of the internal battery is reduced to about 1 h 20 min if left
in the machine.
REMEMBER:
THE INTERNAL BATTERY OF THE NAGRA-D II WILL ONLY
CHARGE WHEN THE MACHINE IS TURNED ON AND IN PARK OR
LOAD POSITIONS.
REMOVING THE INTERNAL BATTERY PACK
The internal battery of the NAGRA-D II is considered as an integral component of the machine, and it is not
something that is supposed to be changed regularly. To remove it, switch off the machine by pressing the
POWER button, and disconnect any external power supply presently connected to the power socket on the right-
hand side of the machine. Loosen the two deck fastening screws on the front of the main control panel. Lift the
deck plate of the machine until it is supported by the bracket on the right-hand rear side of the case. Disconnect
the battery power cable from the socket. Lift the right-hand side of the metal fastening cover from the battery
pack, using a screwdriver, and gently lift it to the left being careful that it does not touch the circuit boards.
Carefully remove the battery pack and replace it with a charged one.
NOTE:
If the internal battery is removed from the machine for more than a few minutes then the internal
settings of the machine will be lost.
There are several different powering methods other than A.C. the different possibilities are all discussed on the
following pages.