Solar Battery Cable: Components, Types, and Factors to Consider

Here’s all you need to know about solar battery cable.

If you think of producing clean energy from solar for your home to live off the grid, you need sufficient battery storage.

These electrical connections need thick solar battery cables to transmit the current generated by the panels to the storage pack.

Similarly, it would be best to have the cables for battery-to-home wiring.

Read on to learn more about these cables. We’ll cover their types, components, connectors, etc.

What Is a Solar Battery Cable?

Also known as a photovoltaic cable, a solar battery cable is a specialized electrical wire for solar power systems to link and power various system components.

These include solar panels, solar batteries, charge controllers, and inverters.

These wires usually have a broad operating temperature range that enables them to operate in freezing temperatures during winter and hot weather in the summer without degrading.

Also, they come in different thicknesses (gauges) to handle various electric current and voltage ranges.

Solar Battery Cable Components

These components are inclusive of the features and characteristics of these cables, which include the following.

Features

Conductor

Conductors are the parts of these cables and primarily consist of copper or aluminum solid cores or stranded wires.

Stranded copper wires are more typical because the material has a high conductivity rating.

Solar panel connector cables (photovoltaic cables)

Aluminum conductors will increase energy losses along the line, and we need to store as much as possible when dealing with solar. So, copper is the de facto material.

Insulation

Wires must have insulation around them to shield the conductor from the elements, current drain, shorting, mechanical damage, etc.

The typical insulation materials used for solar battery cables are EPDM and XLPE.

The former (Ethylene Propylene Diene Monomer) is weather, abrasion, and temperature resistant, while XLPE (Cross-Linked Polyethylene) is UV-resistant and offers superb electrical properties.

Jacket

A jacket or sheath is a solar cable’s outermost layer that protects the shield (if present) and the inner insulation from the elements, UV radiation, extreme temperatures, damage, chemicals, etc. Typical jacket materials include PVC, XLPE, and CSPE.

Connectors/Terminals

Wire connectors like MC4 are regular in solar battery cable connections because they are easy to use and provide secure connections to the solar system components.

MC4 socket connectors for solar panel cells

Others include the following.

Anderson power connectors
Battery terminal lugs
Screw terminal connectors
Tyco Solarlok connectors
H4 connectors
Ring terminals

Characteristics

Solar battery wires have these two characteristics.

Electrical Ratings

These cables have varying voltage and current ratings to meet the requirements of the application area.

The primary factor determining this electrical rating characteristic is the cable thickness, but you don’t have to sweat about it.

Each cable has its electrical rating written on it, so you don’t have to go around measuring the thicknesses.

Temperature Ratings

Since some solar battery cables run outdoors from the panels to batteries via charge controllers, they should be temperature resistant.

This property will ensure the power keeps flowing regardless of the external conditions.

Types of Solar Battery Cables

Solar battery cables are available in these eight types.

Photovoltaic DC Cables

These wires link solar panels to inverters or charge controllers, which involve transmitting DC power from the panels.

Solar panel connections above a camper

They usually have UV-resistant and weatherproof insulations/jackets to safeguard the conductors feature MC4 connectors at the ends.

Branch Cables

If your setup features multiple solar panels, you must use branch cables to link them to form parallel or series connections.

These cables carry DC power to an inverter or combiner box.

Trunk Cables

These wires connect the combiner box to the inverter, transmitting the combined power from the string of panels for conversion to AC.

Therefore, they are thicker than photovoltaic and branch cables to handle the high current levels.

Battery Interconnection Cables

Most off-grid solar installations include multiple batteries, and you must use battery interconnection cables to form the bank.

Solar power storage batteries with battery interconnection cables

The wires feature thick, flexible copper conductors with color-coded insulations for easy identification.

These cables also link the power bank to the charge controllers and inverters.

AC Cables

As the name suggests, these cables transmit AC from the inverter to the grid for sale or your house wiring to power your electrical appliances and devices.

AC runs at a higher voltage than DC, so these cables have higher current and voltage ratings (larger wire size) than photovoltaic cables.

Jumper Cables

Jumper wires connect components like inverters to distribution panels and charge controllers to battery banks.

You can also use them as battery-to-inverter cables. Their distinguishing characteristic is a short length.

Grounding Cables

The name is self-explanatory. Ground cables link the solar system components, such as the inverter, to grounding rods for safety and electrical code compliance.

MC4 Extension Cables

These wires extend the reach of MC4 connectors if the cables can’t reach the solar panels or other system components.

They eliminate the need for custom solar cable assemblies or wire splicing.

MC4 connectors for a solar panel cell

Factors to Consider When Selecting Solar Battery Cables

Consider these factors to select the most suitable solar power installation cable.

Solar Cable Type

We’ve listed the cable types above, so find the matching one for the specific wiring area in the system.

Electrical Rating

The AWG or gauge is the primary factor determining an electrical wire’s rating.

So, pick the appropriate cable type that can handle the current requirements in the system.

It should have a slight allowance to cater to the maximum voltage/current or spikes.

An engineer securing PV cables using a cable tie for a solar roof installation

Remember that the lower the gauge, the thicker the cables, meaning they can handle higher electrical currents with minimal voltage drops, especially if the line is lengthy.

Environmental Conditions

The insulation and jacket material determine the external conditions these cables can handle.

Consider things like UV resistance, weather resistance, capability to withstand extreme temperatures, etc.

Connector Compatibility

A solar system installation is easier if the components have compatible connectors.

Wire Length

Measure distances between system components to buy appropriate wire lengths; they should be slightly longer to allow flexibility.

If using lengthy wires, consider their gauge to prevent voltage drops that can affect power distribution.

Cost

The solar battery cables cost should be within your budget, but give quality a higher priority. At least ensure they comply with industry standards, such as NEC, and have certifications from organizations like UL.

Conclusion

Solar battery cables might seem the same, but they have slight physical differences depending on the type.

For instance, AC and trunk cables are usually thicker than photovoltaic wires because they handle more electric current.

Their insulations can also differ depending on the installation area. But the conductor material is the same (copper).

You can learn more about 6-gauge battery cables in this article, and leave your feedback in the comments below.