 |
Bulldog
PowerPak™
Portable
Power
Systems |
 Solar/DC/AC
Rechargeable
110v Portable Power Systems |
Portable electronic equipment consumes power as Amps (Amperes)
at various rates depending upon the type of equipment and what types of
functions are being used. In general physical motion (motors),
heat and
bright light consume more power than low light and
solely electronic functions without motors.
The more Amps consumed, the faster a battery charge is depleted.
Battery capacity is measured as AmpHrs.
To determine how long a piece of equipment may run using a fully charged
battery, one simply divides the AmpHrs capacity of the battery by how many
Amps a device uses. Theoretically, an 18 AmpHr battery could run
a 1.8 Amp device for 10 hours at 100% efficiency.
However, inverters are not that efficient; we recommend assumption
of 60% efficiencyª for practical expectations. So, to estimate
operating life:
Hours Life = AmpHrs / Amps x .60
If you only know the wattage of a device you may calculate Amps for
estimation purposes using:
Amps = Watts / Volts
|
Bulldog PowerPak™
Note ª : power conversion and battery life
are subject to a wide number of variables. These include chemical
potential charges, environment temperature, circuit thermal resistance,
as well as load factors of equipment connected to the system. Also,
because of loss through the inverter, Amps (AC) are less than Amps (DC)
actually consumed. Each of these variables are impossible to estimate
for general purposes. Therefore any estimation is inherently imprecise.
Assuming 60% efficiency should yield a practical expectation. |
| See the Equipment table for examples
of typical power consumption for various types of portable electronics.
Battery Life calculations are further complicated
by simultaneous recharge using solar panels, or 12vDC connections.
In this case recharge Amps IN are roughly equivalent to utilized Amps OUT.
For Example:
-
If your equipment consumes 1.8 Amps, but a solar panel is simultaneously
resupplying the battery with 1.2 Amps, then the net consumption is only
.6 Amps. At that very low consumption per hour, an 18 AmpHr battery
would theoretically last 30 hours. In this example you could run
your gadget all day without problem.
.
(note: very few places on earth have 30 hours of uninterrupted
sunlight at any given time of year)
-
Alternately, if your equipment consumes 7 Amps, solar panel provides 1.2
Amps, net 5.8 Amp consumption. 18 AmpHr battery would last only 3.1
hours, even with the solar panel. In this example to increase battery
life, you need to reduce Amp consumption (turn off equipment, reduce brightness,
etc.) and/or use additional solar panels to increase recharge 1.2 Amps
per additional panel.
.
Doing so, equipment reduced to 6 Amps, using (3) solar panels providing
1.2 Amps each (for 3.6 Amps INput), net 2.4 Amp consumption. 18 AmpHr
battery would now last 7.5 hours in continuous use.
In any case, when equipment use is ended, the system battery can be fully
recharged via solar, DC vehicle system or the AC recharger.
The time to fully recharge the battery depends upon the AmpHr size of
the system battery and how many Amps are input.
See Recharge Chart at below right. |
.
| Battery
Life (Hrs) ¹ |
Battery
Life (Hrs) ²
(w 20watt
1.2amp solar panel) |
Equipment¹
Amps/hr |
BatteryAmpHrs (AH) |
Net²
Amps/hr
(OUT vs IN) |
BatteryAmpHrs (AH) |
| 7AH |
18AH |
34AH |
7AH |
18AH |
34AH |
0.5
1
2
3
4
6#
8# |
14
7
3.5
2.3
1.8
1.2
0.9 |
36
18
9
6
4.5
3
2.3 |
68
34
17
11.3
8.5
5.7
4.3 |
-0.7
-0.2
0.8
1.8
2.8
4.8#
6.8# |
no loss
no loss
8.8
3.9
2.5
1.5
1.0 |
no loss
no loss
22.5
10.0
6.4
3.8
2.6 |
no loss
no loss
42.5
18.9
12.1
7.1
5.0 |
¹ Equipment Amps OUT only, no
solar panel or other INput connected.
..²
Equipment Amps OUT minus 1.2 Amps IN from single 20watt solar panel
connected simultaneously with equipment
utilization.
#Not recommended for use with equipment drawing more
than 4 Amps. |
| Battery
Recharge (Hrs) |
| Source |
INput
Amps/hr |
Battery (AmpHrs) |
| 7AH |
18AH |
34AH |
5watt panel
10watt panels
20watt panels
25watt panels
40watt panels
60watt panels
80watt panels
12vDC vehicle†
AC Charger‡
AC Charger‡ |
0.3
0.6
1.2
1.5
2.4
3.6
4.8
4
1.2
2 |
23.3
11.7
5.8
4.7
2.9
1.9
1.5
1.8
5.8
3.5 |
60.0
30.0
15.0
12.0
7.5
5.0
3.8
4.5
15
9 |
113.3
56.7
28.3
22.7
14.2
9.4
7.1
8.5
28.3
17 |
Assuming Battery fully discharged,
No Equipment connected,
1.2 Amps IN per 20watt solar panel.
†Amps IN from vehicle may vary.
‡Amps IN from AC Charger auto regulated,
actual time may vary. |
.
| Typical Electronic
Equipment |
Power
Consumption |
Max
Hours *
BatteryAmpHrs (AH) |
| 7AH |
18AH |
34AH |
Medical Electronic
Monitor
Laser Printer
Small Portable Printer
Notebook Computer
Personal Computer (full size)
Large Portable TV/CRT monitor
Small Portable TV/LCD monitor
Very Small Portable TV/radio
Stereo Amplifier
Boom Box
DVD player (only)
100watt Light Bulb
40watt Light Bulb
25watt AC charger (typical)
PalmPilot
Cell Fon |
2.5 Amps
5.0 Amps#
1.5 Amps
3.0 Amps
3.5 Amps
2.0 Amps
.8 Amps
40mAmps
2.4 Amps
1.2 Amps
.2 Amps
0.9 Amp
0.36 Amp
.25 Amp
0.4 Amp
90mAmps |
2.8
1.4
4.7
2.3
2
3.5
8.75
175
2.9
5.8
35
7.8
19.4
28
17.5
77 |
7.2
3.6
12
6
5
9
22.5
450
7.5
15
90
20
50
72
45
200 |
13.6
6.8
22.7
11.3
9.7
17
42.5
850
14
28
170
38
94
136
85
377 |
* All times estimated. Equipment power consumption
varies. Actual time depends on specific equipment model, settings
and specifications.
Hours calculated as Equipment Amps into battery AmpHr
(AH), assuming battery in original condition, fully charged, and
WITHOUT simultaneous recharge from solar panels.
Use with solar panels extends battery life / operating
time.
#Not recommended for use with equipment drawing more
than 4 Amps. |
Special direct DC output versions,
fully universal international 110/220vAC versions and other speciality
custom versions available.
Contact
us for further information. |
© 2006 GeoData Systems Management
Inc.
All Rights Reserved
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