# How to size the right inverter

Views 1 Like
Edit Link Remove
Add up to 3 more photos
Victron Energy 12V 180Va Phoenix Inverter
Inverters are electrical devices that convert DC battery power to 240V AC power to allow you to run appliances.

They come in different power capacities suitable to power small devices such as phone/tablet chargers, right up to refrigerators.

## Define Your Load

Before purchasing an inverter, you need to know the power draw of your appliance in watts. You can find this information in the manufacturers specifications for the appliance shown in either watts or amps.

If only amps are shown, you'll need to convert that to watts by multiplying the amps by voltage. For example, if the appliance draws 0.5 amps, multiply 0.5 amps by 240 volts to get 120 watts (A x V = W).

Some appliances also need a surge of power to start up, though the surge can last only a fraction of a second, it can be up to 2.5 times the rated running watts of the appliance.

If connecting multiple appliances, you'll need to add the total watts and allow for the total start up surge.

If applied to the example above, the surge could be up to 300 watts.

## Inverter Power Ratings

The specifications on most inverters give 2 capacity values.
• Continuous Power Watts - The AC power output available.
• Peak Power Watts - The AC power output available for a split second.
The Peak Power Watts for most inverters is usually around double the capacity of the Continuous Power Watt rating.

If applied to the example above, you would need a 175W inverter with a peak of 350W

## Battery Capacity

You'll need to determine how much DC battery capacity is required to run your appliance. To calculate this, divide the AC running watts by your nominal battery system voltage and multiply the result by 1.1. (WAC / VDC x 1.1 = ADC)

If applied to the example above, for a 12V system, 120WAC / 12VDC x 1.1 = 11ADC
The appliance will draw 11Amps DC per hour.
Edit Link Remove
Add up to 3 more photos
Victron Energy 12V 220Ah Deep Cycle AGM Battery

## Battery Ratings

Deep cycle AGM batteries are rated in ampere-hours (Ah) . A battery rated at 220Ah can deliver 220 DC amps for 1 hour before it's considered flat.

Typically, you can damage an AGM battery if you discharge it more then 50%, so you would consider a 220Ah AGM battery to only have 110Ah of usable DC power.

If applied to the example above, you could run your 11 amp appliance for 10 hours before you would need to recharge your battery.
Tags:
Have something to share, create your own Guide...
Explore more Guides
• ## How to Pick the Right Solar Inverter for Your System

Published by:
• ## Pure Sine Wave Power Inverter: The Elinz Electronics Advantage

Published by:
• ## How to Pick the Right Solar Charger for Your System

Published by:
• ## Solar Chargers vs. Power Inverters

Published by:
• ### Large Shell Power Inverter M Sine Wave 3000W/6000W 12V-240V With 20 Amp Charger

AU \$239.90 Buy It Now
• ### Solar Grid Inverter 1.5 KW

AU \$147.00 Buy It Now
• ### Large Shell Modified Sine Wave Power Inverter 3000W/6000W 12-240V Car Plug Cable

AU \$52.26 Buy It Now
• ### 300W/500W Pure Sine Wave Car Power Inverter DC 12V TO AC 220V Converter AU Sell

AU \$68.95 Buy It Now
• ### 3000W (6000 watt max) Power Inverter 12V-240V M Sine Wave Power Charger Car Home

AU \$3.08 Buy It Now
• ### Victron 12V 500W Pure Sine Wave Phoenix Inverter - 5 YEAR WARRANTY

AU \$246.00 Buy It Now
• ### 2000W-4000W DC 12V to AC 240V Modified Sine Car Power Inverter Charger Converter

AU \$50.14 Buy It Now
• ### Pure Sine Wave Inverter 1000W (2000W Max) 12VDC-240VAC Car Plug Cable 1AMP USB

AU \$124.99 Buy It Now
• ### Victron 12V 375W Pure Sine Wave Phoenix Inverter - 5 YEAR WARRANTY

AU \$164.95 Buy It Now
• ### 3kw PV SOLAR GRID CONNECT INVERTER

AU \$150.00 Buy It Now
• ### Solar power inverter

AU \$80.00 Buy It Now
• ### MPPT 1000W Grid Tie Inverter 18V or 24V/36V Pure Sine Wave Inverter 230V Output

AU \$134.99 Buy It Now
• ### Modified Sine Wave Power Inverter 2000W 12V 24V-240V W/ Car Plug Cable

AU \$55.99 Buy It Now
• ### Pure Sine Wave Panel Solar Grid Tie Micro Inverter MPPT 22-60V 600W To AC 230V

AU \$104.99 Buy It Now
• ### 3000W CE MODIFIED SINE WAVE POWER INVERTER DC12V to AC240V / Battery Charger LCD

AU \$1.00 Buy It Now
• ### LCD Car Pure Sine Wave Power Inverter 1000W peak 2000W 12V/24V/48V to 240V 50HZ

AU \$175.00 Buy It Now
• ### Large Shell Pure Sine Wave Power Inverter 2000W/4000W 12V-240V Remote Control

AU \$214.99 Buy It Now
• ### Growatt 3000S Single MPPT Small 3.0 kW Solar Inverter

AU \$720.00 Buy It Now
• ### 300W/500W/1000W/1500W/3000W/6000W Watt Power Inverter Pure Sine Wave 12V - 240V

AU \$1.00 Buy It Now
• ### Victron 12V 250W VE.Direct Puresine Wave Inverter

AU \$143.95 Buy It Now
• ### Projecta PW350 12V 350W Pro-Wave Pure Sine Wave Inverter

AU \$195.00 Buy It Now
• ### Aerosharp Solar Inverter 1.5 KW

AU \$199.00 Buy It Now
• ### Solar Grid Inverter 1500 watts

AU \$184.00 Buy It Now
• ### Pure Sine Wave Inverter Power Invert 500W-2000W Modified 12V DC To 110V/220V AC

AU \$46.35 Buy It Now
• ### 2400W / 4800W Modified Sine Wave Inverter Power Battery Caravan 4WD

AU \$169.00 Buy It Now
• ### Pure Sine Wave Power Inverter 600W(1200W Max) 12V-240VAC Car Plug Cable1 Amp USB

AU \$83.99 Buy It Now
• ### 3000W Watt Power Inverter 6000W Max Pure Sine Wave 12V -240V CAR CARAVAN CAMPING

AU \$1.00 Buy It Now
• ### 1000W MPPT Solar Grid Tie Inverter DC20V-45V to AC230V Pure Sine Wave Inverters

AU \$134.99 Buy It Now
• ### 2000W (4000W Max) Power Inverter Car DC 12V to 240V AC Converter USB Charger OP

AU \$1.00 Buy It Now
• ### Pure Sine Wave Power Inverter 4000W (8000W Max) 24V-240V With 20 Amp Output Box

AU \$489.90 Buy It Now