Niterider light heads can also be powered from a surface battery. These are the calculations
for cable gages, the battery voltage required and other details for the available bulb
configurations and cable lengths.

Using Surface Supplied Power via a Cable

QUESTION: Three years ago, I purchased a dual 35 watt (NiteRider) light from to install on my superlite 27 dive helmet. Unfortunately, my umbilical being 250 feet long causes a voltage drop, causing a weak beam. No one was able to inform me if you sell a transformer to compensate for surface supply for the NiteRider light . I would enjoy having dual 35 watts of white light for a change....

ANSWER: We do not make an adjustable power supply for umbilical surface supplied power, although they are available. For you to use 2 X 35 watts on an umbilical from the surface and have a bright white light on your Superlite Helmet is not an easy thing to accomplish. It depends on the Wire Gauge of the cable you are using and how long it is. The cable is like a resistor so it cuts down the voltage and amperage the longer and thinner the cable is.

If you used two 12volt car batteries (or one 24 volt Marine Battery) wired together, in series, to give you 24 volts at the surface and then you hooked up 300 feet of 16 gauge 2 conductor cable you would have a bright light at the end. Just be sure you don't turn off one of the lamps because the other will blow up because you will have too much voltage. You would have to have both lamps on before you hooked it up to the battery or you would blow the lamps turning the switch on from one to both bulbs (I'm assuming you have our dual beam headlamp with the four position switch. I can give you other calculations for different cable lengths and wire gauges but this set up would be the easiest.

 

NiteRider Single Beam Dive Lights - surface supplied power via umbilical cable calculations.

Lamp
Wattage
Lamp Voltage
Rated Lamp Current
Lamp resistance ohms
Wire Gage
Cable resistance per 1000ft
Cable Distance in feet
Total Wire Distance feet
Total Cable Resistance
Total Resistance
Power supply Volts Needed
Power Supply Wattage
Volts at lamp
Cable Voltage Drop
Lamp drive factor
Power Efficiency %
12
13.2
0.91
14.52
18
6.39
100
200
1.28
15.8
14.36
13.05
13.2
1.16
1
91.92
12
13.2
0.91
14.52
18
6.39
200
400
2.55
17.07
15.52
14.11
13.2
2.32
1
85.04
12
13.2
0.91
14.52
18
6.39
300
600
3.83
18.35
16.68
15.16
13.2
3.48
1
79.12
20
13.2
1.52
8.71
18
6.39
100
200
1.28
9.99
15.13
22.92
13.2
1.93
1
87.21
20
13.2
1.52
8.71
18
6.39
200
400
2.55
11.27
17.07
25.86
13.2
3.87
1
77.33
20
13.2
1.52
8.71
18
6.39
300
600
3.83
12.54
19
28.79
13.2
5.8
1
69.45
35
13.2
2.65
4.98
18
6.39
100
200
1.28
6.26
16.59
43.99
13.2
3.39
1
79.59
35
13.2
2.65
4.98
18
6.39
200
400
2.55
7.53
19.97
52.95
13.2
6.77
1
66.09
35
13.2
2.65
4.98
18
6.39
300
600
3.83
8.81
23.36
61.94
13.2
10.16
1
56.52
70
13.2
5.3
2.49
18
6.39
100
200
1.28
3.77
19.97
105.9
13.2
6.77
1
66.09
70
13.2
5.3
2.49
18
6.39
200
400
2.55
5.04
26.74
141.8
13.2
13.54
1
49.35
70
13.2
5.3
2.49
18
6.39
300
600
3.83
6.32
33.52
177.76
13.2
20.32
1
39.39
12
13.2
0.91
14.52
16
4.02
100
200
0.8
15.32
13.93
12.66
13.2
0.73
1
94.76
12
13.2
0.91
14.52
16
4.02
200
400
1.61
16.13
14.66
13.33
13.2
1.46
1
90.04
12
13.2
0.91
14.52
16
4.02
300
600
2.41
16.93
15.39
13.99
13.2
2.19
1
85.77
20
13.2
1.52
8.71
16
4.02
100
200
0.8
9.52
14.42
21.85
13.2
1.22
1
91.56
20
13.2
1.52
8.71
16
4.02
200
400
1.61
10.32
15.63
23.68
13.2
2.43
1
84.43
20
13.2
1.52
8.71
16
4.02
300
600
2.41
11.12
16.85
25.53
13.2
3.65
1
78.33
35
13.2
2.65
4.98
16
4.02
100
200
0.8
5.78
15.33
40.65
13.2
2.13
1
86.11
35
13.2
2.65
4.98
16
4.02
200
400
1.61
6.58
17.46
46.3
13.2
4.26
1
75.6
35
13.2
2.65
4.98
16
4.02
300
600
2.41
7.39
19.59
51.94
13.2
6.39
1
67.39
50
13.2
3.79
3.48
16
4.02
100
200
0.8
4.29
16.24
61.52
13.2
3.04
1
81.27
50
13.2
3.79
3.48
16
4.02
200
400
1.61
5.09
19.28
73.03
13.2
6.08
1
68.44
50
13.2
3.79
3.48
16
4.02
300
600
2.41
5.89
22.33
84.58
13.2
9.13
1
59.13

(1) Never disconnect power connectors underwater
(2) Both beams must be turned on to prevent over voltage
(3) If one lamp fails or is turned off, the other one will instantly blow
(4) To prevent electrocution use only an isolated, grounded power supply with a ground fault interrupter

Single Beam Lamp CAUTIONS:
(1) Never disconnect power connectors underwater
(2) To prevent electrocution use only an isolated, grounded power supply with a ground fault interrupter

Lamp Wattage Configuration
Total Lamp Wattage
Lamp Voltage
Rated Lamp Current
Lamp resistance ohms
Wire Gage
Cable resistance per 1000 ft
Cable Distance in feet
Total Wire Distance ft
Total Cable Resistance
Total Resistance
Power supply Volts Needed
Power Supply Wattage
Volts at lamp
Cable Voltage Drop
Lamp drive factor
Power Efficiency %
2 x 35 watt
70
13.2
5.3
2.49
18
6.39
100
200
1.28
3.77
20
106.06
13.23
6.77
1
66.14
2 x 35 watt
70
13.2
5.3
2.49
18
6.39
200
400
2.55
5.04
26.7
141.59
13.16
13.54
1
49.27
2 x 35 watt
70
13.2
5.3
2.49
18
6.39
300
600
3.83
6.32
33.5
177.65
13.18
20.32
1
39.36
12 watt / 20 watt
32
13.2
2.42
5.45
18
6.39
100
200
1.28
6.72
16.3
39.52
13.2
3.1
1
81.01
12 watt / 20 watt
32
13.2
2.42
5.45
18
6.39
200
400
2.55
8
19.4
47.03
13.21
6.19
1
68.08
12 watt / 20 watt
32
13.2
2.42
5.45
18
6.39
300
600
3.83
9.28
22.5
54.55
13.21
9.29
1
58.72
2 x 35 watt
70
13.2
5.3
2.49
16
4.02
100
200
0.8
3.29
17.46
92.59
13.2
4.26
1
75.6
2 x 35 watt
70
13.2
5.3
2.49
16
4.02
200
400
1.61
4.1
21.72
115.18
13.2
8.52
1
60.78
2 x 35 watt
70
13.2
5.3
2.49
16
4.02
300
600
2.41
4.9
25.98
137.76
13.2
12.78
1
50.81
12 watt / 20 watt
32
13.2
2.42
5.45
16
4.02
100
200
0.8
6.25
15.15
36.72
13.2
1.95
1
87.15
12 watt / 20 watt
32
13.2
2.42
5.45
16
4.02
200
400
1.61
7.05
17.09
41.44
13.2
3.89
1
77.22
12 watt / 20 watt
32
13.2
2.42
5.45
16
4.02
300
600
2.41
7.85
19.04
46.16
13.2
5.84
1
69.32
(1) Never disconnect power connectors underwater
(2) Both beams must be turned on to prevent over voltage
(3) If one lamp fails or is turned off, the other one will instantly blow
(4) To prevent electrocution use only an isolated, grounded power supply with a ground fault interrupter

 

 

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