Type Watts * Amps
Television 19" 100-160 1.2 A
my 32" TV 90
Flat pannel TV 80-150
VCR 40-60
Satelite Dish 30+
Sterio 50-350
Portable Sterio 40-50
Computer Laptop 50-75
loaded super Laptop 140
Computer Desktop (1) 120-250 2.5-3.5
Computer Tower (2) 300-450 3.5-6.5
CRT Monitor 15" 801.5 A
17" 651.8 A
19" 802.1 A
LCD Monitor 15"20
LCD Monitor 19"40
Printer - Inkjet 50-75
Printer Laser 600
mobil phone charger 20
Digital Camera 38-45
drill/ camcorder
Halogen Spotlight 1000
portable vacuum 525
Whole house vacuum 11
Coffee Maker 600-800 5-6.7
Heater 500-1,500 4-12.5
Table Fan 200
Leaf Blower 13
Snow Blower 13.5
DC Appliances:
Heavy duty tire pump - 30 Amps
350 W power inverter - 32 Amps
Auto cigarette lighters typically have a 20A fuse.
It may take 10 minutes or more to blow at 25% over it's rated curent.
Source: Fuses | bcae1.com
Type WattsAmps
Microwave .5 cu. ft. † 600-1,500
Microwave .8 - 1.5 cu. ft. 2,100
refigerator 600-1,100
blender 450
Furnace Fan (1/3hp) 1,200
1/3 HP submersible pump 920
1/3 HP Heating system fan 600 5
1/2 HP Heating system fan low-heating 720 6
1/2 HP Heating system fan high-air conditioning 1080 9
Vacume 750
Cell Phones 4
Fluorescent Light 4
Radio 9
Ham Radio
50 W mobile
5-20
12V
CB Radio  
Tools 24
3/8" Drill 350
1/2" Drill 750
7 1/4" Circular Saw 1,000-1,400
reciprocating saw 500
16" Elect. Chain Saw 12
Car Vacuum 80
Air compressor 80
Heavy duty
Air compressor
30
Elect. Coolers 48
Engine Starter on
Battery Charger
60
12V
See Also: www.donrowe.com/inverters/usage_chart.html
www.eurobatteries.com/sitepages/choosinginverter.asp
Common Household Appliance Energy Use

* See Volt-Amp to Watt conversion below
† Microwave input watts = 1.5 - 1.7 x output watts
(1) Dell 2350 - 200W, Dell 4550 & 8300 - 250W continuous, iMac 15" 130W
(2) Dell Precision 650 - 460 W, Mac G4 460W 6A

See Also: Charging Volts and Amps for consumer electronics.

UPS - Uninterruptible Power Supplies:
The most common are Battery Backup units which switch from direct power to battey in in 4-8 ms. A "True" UPS runs off batteries constantly so there is no switchover time. The 4-8 ms. switchover does not affect most computers. Battery life is typically 3-6 yrs.
See UPS

Typically 100 watts of supplied UPS power will run 100 watts of incandescent lightbulbs, but only 71.4 watts of a typical capacitor input switching type computer power supply, and nearly 100 watts of a PFC computer power supply.

Batteries will last longer (more discharge cycles) if discharged at a lower rate.
1/2 the rate will tripple the life.

Battery RunTime

Conext Battery Backup
300VA/180 Watts - 170 Watts 4 min 100 Watts 11 min.
500VA/300 Watts - 201 Watts 4 min/ 100 Watts 15 min
APC
Watts 50 100 200 300 400
VA 80 160 320 480 640
350VA/200 Watts 21 min 8 min. 2 min 
500VA/300 Watts 57 min 23 min. 7 min. 2 min
650VA/390 Watts 83 min 39 min. 17 min. 9 min
725VA/450 Watts 82 min. 39 min 16 min. 9 min 5 min.
(Battery age may affect results.) Conext, APC

Volt-Amp to Watt conversion

True Power (watts) = Volts (RMS) x Amps (RMS) x Power Factor

where V = Volts, A = Amps pf = the power factor of the load, applies to all electrical loads.

A standard 120 V household current swings between +170 V and -170 V in a sine wave pattern. the RMS value (root-mean-square) is 1/SQRT(2), or about 0.707 times the peak. This despite the fact that the average value of a sine wave is about 0.637 times the peak.
See:
Teaching RMS from L. B. Cebik, W4RNL.
Introduction to Signals at Bucknell

In the case where the load acts purely resistive, such as that of an incandescent light bulb, heater or a PFC (Power Factor Corrected) switching power supply, the pf will equal 1 or nearly 1. For all other cases, the pf will vary between 0 and 1, and for a typical capacitor input switching type computer power supply, a power factor of about 0.714 is usually exhibited.

Typically 100 watts of supplied UPS power will run 100 watts of incandescent lightbulbs, but only 71.4 watts of a typical capacitor input switching type computer power supply, and nearly 100 watts of a PFC computer power supply.

Example:

A typical capacitor input switching computer power supply is 200 watts. The VA output equivalent can be calculated as follows:

watts = VA * pf, or, VA = watts / pf
VA = 200 Watts / 0.714(pf) = 280 VA

so 280 VA of the UPS supplied power will be needed by the 200 watt computer power supply at full draw.

Another faster way to express this, is

Computer Power Supply in Watts * 1.4 = UPS VA
200 Watts * 1.4 = 280 VA

AC Watts to DC Amps AC Watts divided by 12 x 1.1 = DC Amps

Some appliances or tools, such as ones with a motor, require an initial surge of power to start up ("starting load" or "peak load"). Once started, the tool or appliance requires less power to continue to operate ("continuous load"). So, power inverters (DC battery to AC) and generators are sometimes rated by peak and continuous load. Source: The Volt-Amp to Watt conversion information above came from a web site named Sutton Designs (www.suttondesigns.com/doctext/pf.html) which is no longer available.

DC Inverter:
12 volt inverters require approximately ten (10) amps DC input for each 100 watts output power used to operate an AC load.

e.g. It will require 10 amp hours of battery to operate a 100 watt bulb for 1 hour. The battery rating should be twice this (i.e. 20 amp-hours for maximum battery life and performance.

Meters: Amp, watt, volts
Watt Meters : AstroFlight

See Also:
Power Outage Survival
www.donrowe.com/inverters/usage_chart.html
Charging in technology here
Hand Crank flashlights and Mobil Phone Chargers and Solar Panels in products here.
Solar Tutorial www.donrowe.com/inverters/inverter_faq.html
Wire Size
UPS


last updated 16 Sept 2004