September
2017
Sentinel V SC and RT Operation Manual
Page 8
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Power Considerations
Use the following section to determine the power requirements for the Sentinel V Self-Contained ADCPs.
•
The Sentinel V system uses +18 VDC to operate.
•
Depending on the type of housing the system is configured with, the ADCP may use a battery
pack, lithium battery pack (optional), individual D cell batteries, or external power.
•
If the Sentinel V is configured with the optional end-cap connector, then external power can be
used. The voltage must be +12 to 20 VDC. The optional
Sentinel V battery pack is shipped inside the system but not connected.
Connect the
battery and seal the Sentinel V before deployment.
Sentinel V with D cells are shipped without batteries inside the system.
Install the batteries
and seal the Sentinel V before deployment.
The External Battery Case holds two battery packs that are shipped inside the case but not
connected. Connect
BOTH
batteries and seal the external battery case before deployment.
It
is necessary to remove the top battery in order to connect the bottom battery cable.
See
Replacing the External Battery Case Packs
Transmitted Power
For the Sentinel V, a fresh battery pr18 VDC. Batteries spend most of their life at a nominal volt-
age of +14 VDC. Using 18 VDC will increase the range by 5 to 10% depending on conditions.
The optional lithium battery provides 15.6 VDC with a capacity of approximately 1900 Wh. The battery
includes a safety circuit that protects the battery and users against short circuits and provides users the
ability to test the pack. The circuit also turns the battery off at its end of life, before the battery fully dis-
charges. This happens when about 97% of the battery’s capacity is depleted.
Power on Cycle
The power supply or battery pack must be able to handle the inrush current as well. Inrush current is the
current required to fully charge up the capacitors when power is applied to the Sentinel V Series ADCP.
The capacitors provide a store of energy for use during transmit.
The inrush current is as high as 0.8
Amps RMS at 9.2 VDC.
The ADCP will draw this
amperage
until its capacitors are fully charged.
If the
power supply or battery pack limits the current or the power drop on the cable is significant, then the
power on cycle will take longer. It can take up to three minutes. The power must not shut down during the
inrush current draw, as this may not allow the Sentinel V Series ADCP electronics to start.
Before using the optional Lithium battery pack, always run the battery self-test. See
Instruments with high inrush currents occasionally trigger the optional Lithium battery pack
short circuit detection, which turns the battery off. If this happens, do the following:
•
Disconnect the battery and touch the ADCP’s touch sensor for about 45 seconds to
one minute. Connect the battery and then the ADCP should power on normally.
•
If the ADCP still does not power on, connect the
and then connect the battery pack. Once the ADCP is connected and ReadyV started,
unplug the AC adapter. The ADCP will work normally after that.
