Customer Question: What Cables Do I Need For My Power Inverter?

by Justin Gray

Answer: Which cables you need are based on – How long the cable needs to be and how many watts you’ll be running. Take a look at the charts below, we have 12V, 24V, and 48V charts.

Video Located Here:

Glossary of Terms:

• A = Ampere or "Amp" for short
• V = Volt
• W = Watt
• AWG = American Wire Gauge, the national standard for wire sizes

Cable Length: What is the Round-trip distance?
You’ll need to know what the distance is from the inverter to the battery and back again. If the cable from the inverter to the battery is 5 feet, then the round-trip distance is 10 feet (5 feet to the battery plus 5 feet back to the inverter). 

How many watts are you running?
This is the BIG question! You may have a 10,000W Inverter, but only plan on using 8,000W max. If you never plan on using the 10,000W, you should size your cables for 8,000W.

• To calculate watts using amps (A), multiply Volts (V) times Amps (A). Formula: (V x A = W).
• To calculate amps from watts, take the wattage (W) and divide (/) it by the voltage (V). Formula: (W/V=A)

How to Calculate the Cable Gauge
Take your round-trip cable length and find it on the left side of the chart. Be certain that you're looking at the correct chart; we have one for 12V (Blue Chart), 24V (Yellow Chart), & 48V (Green Chart) systems! Next, locate the Power Inverter wattage you’ll be using on the top of the chart and find the point at which both lines intersect; that is the cable that you need for your application.

Note: Large cable gauges can be split by two or more smaller cables as long as the carrying capacity for those cables meets or exceeds that of the larger cable. For instance, a single 4/0 (0000) cable can carry a maximum of 300A. A single 4AWG cable can carry a maximum of 105A. So, 3x 4AWG cables can replace one 4/0 cable. 

(click to enlarge or download chart) 

How to read the number
Now that you’ve located your cable number, what does it mean? If it is just a number by itself (6, 4, 2, 0, 00, 000, 0000, etc.), then it represents an American Wire Gauge (AWG) size. This is a standard electrical wire number read as “6 AWG”, "4 AWG", or “00 AWG” and is universally understood.

If the number ends with a “k” designation, it is short for “kcmil”. kcmil and MCM cable sizes are interchangeable numbers for large diameter wire/cables. MCM numbers are read as “350 MCM” or “500 MCM”.

(click to enlarge or download chart) 

(click to enlarge or download chart) 

Don't forget the fuse!
*Take note: At the bottom of the chart is the recommended fuse for your inverter size.

The fuse should be placed inline on the positive battery cable (+ or red colored cable) and within 1 foot (12 inches or less) from the battery.

Questions?
We’re here to help!
For Live help, Call us M-F 9a-5p (PST) at 1.800.231.5806.
You can email us at Customerservice@wagan.com