Appendix C: Alvin Power Budgets

(Revised 03/20/08)

The following power budget is based on best estimates of amperes and on-time for loads of various buses. These estimates are subject to review for any specific dive. The power available for science, based on the following estimates, is 154 amp hours of 120VDC.

120V Outboard Bus
VB SW Pump	30 amps	20 min	600 amp min
VB Hydraulics	10	10	100
Hydraulic Pump	30	30	900
Port/Stbd Lift Thrusters	20	60	1200
Heading Thruster	10	30	300
Fwd Thrusters (3)	30	120	3600
Lights (10) (2 amps each)	20	120	2400
Inverter (Idle)	.07	480	35
CTFM	.6	60	35
Total 9170 amp min=153 AH

26V Inboard Buses - Service
CO2 Blower	0.4 amp	480 min	192 amp min
UW Phone (receive)	1.0	480	480
UW Phone (transmit)	17	40	680
Radio	2.0	10	20
Navigation	0.2	480	96
MBT Blow	1.2	5	6
MBT Vent	4	5	20
Emergency Light	.01	480	5
Depth 1	.02	480	10
Releases	20	1	20
Total: 1529 amp min

26V Inboard Buses - Instrument
Imagenex (Science Use)	1.0 amp	0 min	0 amp min
Doppler Sonar	0.2	480	96
Port Strobe	10	2	20
Starboard Strobe	10	2	20
Fwd Strobe (1000 pics)	10	50	500
Acoustic modem	.24	480	115
Depth 2	.02	480	10
Total: 761 amp min

26V Inboard Buses - Control
Motor Controllers	2 amp	120 min	240 amp min
Thruster/Pump Controller	2	120	240
VB Control	5	15	75
Port Manipulator	1.5	480	720
Starboard Manipulator	1.0	60	60
Hydraulic Control	1.0	60	60
Sci Power Control	1.5	120	180
Hold Bus	4	480	1920
Outside Light Control	1.7	240	410
Inside Lights	2	480	960
Total: 4865 amp min

26V Inboard Buses - Data
Video	5 amp	240 min	1200 amp min
Altimeter	.02	480	10
Water Temp 1	.02	480	10
Water Temp 2	.02	480	10
Water Temp 3	.02	480	10
Gyrocompass	2	480	960
Data Collector	2	480	960
Attitude Sensor	.04	480	20
Computer	4	480	1920
Total: 5100 amp min

26V Use Summary
Service	1529 amp min
Instrument	761
Control	4865
Data	5100
Total 12,255 amp min = 204 AH 26V power reflected to 120V bus: 204 AH x 26.5V = 5413 WH 5413 WH / 85% converter efficiency = 6368 WH 6368 WH / 120V = 53 AH from the 120V bus

120V Use Summary
Outboard Bus	153 AH
26V Load	53 AH
Total required to power sub: Power available from batteries: 480 AH x 75% (depth of cycle) Power available for Science (360-206) =	206 AH 360 AH 154 AH

Alvin Emergency Power Budget
Available Battery Capacity
Nominal capacity at 1 amp rate	4.5 Amp-hours
Additional factors:
Age Temperature (0 deg C)	80% 85%
Remaining capacity (.80 x .85 x 4.5) =	3.1
Guaranteed pre-dive capacity:
Each RED battery GREEN battery	85% 60%
Guaranteed total capacity:
Each RED battery (.85 x 3.1) = 2.6x2 = GREEN battery (.60 x 3.1) =	5.2 1.8
Total all batteries: 7.0 Amp-hours

Power Usage
Equipment	Current Drain (amps)	Duration of Use	Amp-Hrs Expended
UQC Receive	1	2 hrs	2.0
UQC Transmit	17	7 min	2.0
Radio Receive	0.5	1 hr	0.5
Radio Transmit	3	5 min	0.25
Service Releases
Basket Port Forward Port Aft Stbd Forward Stbd Aft	20 20 20 20 20	4 sec 4 sec 4 sec 4 sec 4 sec	0.022 0.022 0.022 0.022 0.022
Sub Total: 0.111 AH
Dump Panel Releases
Port Manipulator Stbd Manipulator Buoy Release Battery Tank A Battery Tank B Battery Tank C	8.2 8.2 20 8.2 8.2 8.2	70 sec 70 sec 2 sec 70 sec 70 sec 70 sec	0.159 0.159 0.011 0.159 0.159 0.159
Sub Total: 0.806 AH
MBTBlow Valves	1.2	5 min	0.100
Total Power Expended: 5.766 AH

Note: CO2 Srubber Operation
Fast	0.13 amp-hrs/10 minutes of operation
Slow	0.07 amp-hrs/10 minutes of operation