Aug. 06, 2024
Are you looking for a Battery Cable Size Chart? We have two of them at the bottom of this page.
Please visit our website for more information on this topic.
Some of the most common questions I get asked are &#;what type of battery wire do you use to build the cables?&#; and &#;What size cable should I use for my vehicle?&#;
Below are some descriptions of what we use, information on the gauges of wire and when to use it, and some other technical charts to use. I&#;ll even give you my opinion about if you should be using marine-grade wire on your Dodge Dart&#;..
If you&#;re wondering whether to use a 2/0 battery cable or 1/0 we&#;ll give you the data you need to decide.
Be sure to watch the video at the bottom of the page. We explain which gauge wire is right for every application. And we&#;ll show you how we build cables for you.
We generally use SAE (Society of Automotive Engineers) SGT battery cable. SGT designates the type of insulation. (Wire is rated by several characteristics but most commonly its insulation type. For example &#;THHN&#; is probably what you have for the wiring in your house. THHN stands for &#;Thermoplastic High Heat-resistant Nylon-coated). SGT is a thermoplastic PVC (polyvinyl chloride) insulation rated at 50 volts. It&#;s typically rated for 85 or 105 degrees C.
It usually has a fairly low strand count (meaning the strands are larger), making the wire stiff enough to stay where you put it but is still flexible enough to bend around tight corners.
Buy SGT Battery CableSometimes we use SGX battery cable. SGX uses a high-grade XLP (Cross-Linked Polyethylene) insulation which has a higher temperature rating and is more abrasion-resistant. The trade-off is the insulation is thicker and stiffer. Often it has a higher strand count. If you need a higher temp rating, it&#;s a good choice.
Buy SGX Battery CableThere are several types of &#;Marine&#; wire. It&#;s usually rated for higher temperatures and &#;wet&#; (think submerged) applications. It also has a requirement that it must be &#;self-extinguishing&#;. The marine rating is a Coast Guard legal requirement for marine applications. Do not build a cable intended for marine use out of wire that does not have a marine rating.
Most of the SGT we sell also carry a marine rating (BC-2 rating)
Buy Marine ProductsThink of a fuse link as a very slow-acting (&#;slow-blow&#;) fuse that looks like a piece of wire. Fuse link wire has special very high-temp insulation that won&#;t burn even if the wire becomes so hot that it fuses open.
Its most common use is in alternator wires. It protects the electrical system from a catastrophic failure of the alternator diodes. Without the fuse link, the alternator wire would melt or burn, possibly starting an underhood fire. Other common applications are the wires going to glow plug or intake grid heater relays on diesel engines.
It&#;s usually a 6 to 9-inch piece two wire sizes smaller than the wire it is protecting. For example, a 4 gauge wire would use a piece of 8 gauge fuse link.
Buy Fuse Link WireOFC (Oxygen Free Copper) wire often gets sold by stereo shops to hook up speakers or a high-power amp. Don&#;t waste your money. This stuff is just another way for slick salesmen to get more of your hard-earned money.
What&#;s different about it? Standard wire is AT LEAST 99.90% pure copper. OFC is 99.95% copper. An extra 0.05% copper sounds ok; what&#;s the downside? COST. OFC is often more expensive for the same size as standard cable. So you pay more for NO measurable electric difference (source Wikipedia). The OFC that I have inspected does NOT show that it meets automotive specifications. To make matters worse, I have heard reports of Chinese OFC being undersized for a given wire size. Stick with good quality SAE approved wire.
Just say &#;no&#;. Copper clad is nothing more than copper-plated aluminum. Aluminum has 60% the conductivity of copper so a CCA wire will need to be roughly 2 sizes larger to have the same conductivity. In other words, a CCA wire would need to be 2 gauge to do the work of a 6 ga copper. Just buy copper wire.
For more info see Wikipedia.
For automotive cables, use SAE-rated SGT or SGX battery cable. It works great for automotive applications at a fair price. Do NOT use welding cable, OFC or CCA for underhood applications.
For boats, you must use &#;marine&#; rated wire.
I recommend building cables larger than stock. The manufacturers make stock battery cables as small as possible that barely get the job done. Going up a size or two is worth it in the long run because they do work better and last longer. Isn&#;t that what you want for your car or truck? Something that will work better and last longer.
For very long cables (for example, 15-foot long battery cables to relocate your battery) go one size larger.
10 gauge works for accessory leads, low power alternators, and starter trigger wires
10 Gauge Cables8 gauge works for accessory leads and low power alternators.
8 Gauge Cables6 gauge works for accessory leads and most stock alternators. Battery cables for small engines (like ATVs and sub-compacts). Some stock golf cart wiring.
6 Gauge Cables4 gauge wire makes great accessory leads and alternator wiring (up to about 160A). Many cars use this as a battery cable. Some electric ATVs use #4 for the battery banks. It also makes very good automotive booster cables.
4 Gauge CablesWe recommend #2 wire for 4-cylinder and small 6-cylinder automotive engines, hi-power accessories (like winches, power converters), and alternators over 160A.
Also works great for high-performance golf cart battery banks. Recommended for professional heavy-duty, booster cable (jumper cable) kits.
2 Gauge CablesWe recommend 1 gauge wire for large 6-cylinder or small V8 automotive engines, hi-power accessories (like winches, power converters), and high output aftermarket alternators in the 200A range.
1 Gauge Cables1/0 makes a great battery cable for large or hi-performance 6-cylinder engines and stock V8s.
1/0 Gauge CablesUse 2/0 battery cables for hard-to-crank engines (like high compression, big blocks, or diesel engines), electric vehicle battery banks (depending on controller amperage), and large RV power converters house batteries..
2/0 Gauge Cables&#;
3/0 Gauge Cables3/0 and 4/0 are for very large marine or diesel engines and high-power alternative energy battery banks.
4/0 Gauge CablesWe carry a wide range of wires. Take a look at our wire products today.
If you are looking for more details, kindly visit Suntex Electronics.
Note: The battery cable size charts information comes from a variety of sources and it is used for reference only.
We have not personally verified all the data shown.
American Wire Gauge (AWG) is the standard for denoting wire size in North America. The AWG chart below, the larger the number, the smaller the wire diameter and thickness.
AWGAllowable Amperage of Conductors for Under 50V (Per SAE J-378) Note: Since most wire is rated at 85° use the 80°C values
Every automotive wiring application is different, and because of this every wiring solution is unique. There are a number of factors to consider when choosing an appropriate wire size for use in your application.
While current draw is very important there are other factors to consider:
You don&#;t want a harness that catches on fire due to not having adequate wire for the application, but you also don&#;t want to run 10AWG wire through the whole car, not only would it be incredibly cumbersome and heavy, it would be an expensive endeavour.
The below table is a general guide for automotive use (under 3m lengths), but as per the above factors, other considerations should be made before deciding on a wire size. This table was created for use with Spec 44 wire and may not be appropriate for other types of wire available.
This table isn&#;t the be-all and end-all, but it can help you get started. If you want to be more exact you can calculate the current requirements of what is being powered. Ohms Law can be used to determine what our current requirements are, if we again look at the injectors we can use the equation
Amps = Volts/Ohms
If we are going to use a set of Injector Dynamics IDx injectors we can look up the impedance which is 8.5ohms. While running our car should be providing around 14 volts. Therefore our current is equal to
Amps = 14/8.5
Amps = 1.65
Voltage (V)
Resistance in Ohms (R)
Current in Amps (I)
This means our peak current draw from the injectors will be 1.65A, using the table above, we can easily run each injector on a 20AWG wire.
We can also calculate what size wire we need for items which draw a larger current, like the ignition coils. As an example Haltech IGN-1A coils can draw up to 15A of peak current. Using this peak current will cause us to over-spec our wiring, but can help us to find a ball-park figure. Below is a table showing the effective current draw at 100% duty cycle at different RPMs.
RPMCurrent (A)Charge Time (ms)Engine Cycle Time (ms)Effective Current Draw at 100% Duty Cycle154..125A154..25A154..375A154..5A10,000154..625ATo calculate the above the formula is:
Effective current draw = (current * charge time) / engine cycle time
Referring to the top table, again we would run the ignition coils on a 20 AWG wire. If we needed a power wire to supply all coils we can calculate that as:
Total Amperage = Effective current draw * Number of coils
If we had a 4 cylinder engine revving to 8,000rpm, then our total maximum current for all 4 coils would be 18A.
At first glance this seems like we would need to run 12 AWG wire, but there are a few factors which can be taken into consideration. All 4 coils won&#;t be firing at once, and our calculations are based off the peak current draw rather than the average. On top of this, our rating table is for wire up to 3m in length, and a short run from the ECU to the coils will be less than this. With these combined factors, a 16AWG wire will be sufficient for this application.
As you can see, calculating wire size can be complicated, from finding the draw of various components to finding how long your wire lengths will be, there are a lot of factors to consider. As always PT Motorsport is here to help, and we are happy to answer any questions you might have about your project.
We also have a number of other useful calculators available:
The company is the world’s best Automotive Hook Up Wire supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
Previous: 10 Questions You Should Know about Electric Vehicle Charging Stations
Next: None
If you are interested in sending in a Guest Blogger Submission,welcome to write for us!
All Comments ( 0 )