Solar extension cable AWG?

New EB70 owner from England here.

I want to get a 20 foot extension cable for my PV200 panel but wondered what AWG I need? Available locally are either 10 or 12 AWG.

I would go with the 10 gauge.


Welcome to the forum. It depends on your plans and how much money you want to spend. If you even remotely plan on expanding you solar panel array, you would want to go with a larger gauge (10 gauge). At some point you may want to expand beyond an EB70 and you may need a larger gauge to handle the array you would hook up to it. Just my two cents. Depends on what you want to live with.


14 ga. is more than sufficient for the task.

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Thanks to you all,
In order to future-proof it I should go with 10 AWG.

I would not because the amount of solar the EB 70 can take is limited to around 165 watts. It does not matter how many panels you attach since this will be the limit and 14 ga. will be more than enough to do the job. 10 ga. cables are stiffer, heavier and more difficult to deal with for portable panels. Acopower makes a 14 ga. 20 ’ MC4 extension set that has both wires connected together (a big deal when handling over and over) and is lightweight and you would see no loss.

If you are going to go with a larger unit in the future, the voltage acceptance range of the larger unit will also increase and allow those same 14 ga. wires to pass more wattage. Unless you were going for a fixed very high wattage install, I would not recommend 10 ga. wires.

If low losses are your goal time spent optimally aligning your panels to the sun throughout the day will yield far more wattage improvements than thicker wires ever would.

Here is an example of a small lightweight extension that is more than enough for your needs.

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Thanks Scott,
Have ordered this and delivery to UK is next Tuesday which is really quick!

I have run and tested these sets (6 sets of the extension cables connected) out to 125 feet to my AC200 (running at around 75 volts) with almost no wattage loss. My primary use of all my equipment is for emergency use and temporary setup so I value portability and ease of storage along with setup and handling. If I were setting up a home system with fixed panels and cables, I probably would go to a thicker wire since I would be transmitting a greater amount of power.

I would agree IF you don’t expect to ever use these cables in a larger, higher powered system than the EB70. If you believe you may be moving to a larger system that can take many more watts, 14 gauge may not be enough. (Of course, you could just buy a 10 gauge cable then.)

14 ga. will still be enough unless you invest multiple thousands of dollars into a large system. The mid to large range systems allow much higher voltage which translates into being able to pass a larger amount of electrical current with the same size wire. If you stay 800 or so watts or less you will be fine.

Scott, what do you recommend for extension solar cable for AC200 Max with 3, PV200 watt Bluetti panels.
I really like the idea of both wires together in one cable. I’m looking for 25 to 30 ft and a second one that’s 100ft. Thanks for your thoughts!

Wire-size calculator

Higher amps require thicker cables, so you do not get a voltage drop or the wire heating up.

Here is a good wire-size calculator. The direct link does not work so instead go to then click on the “Plan & Design” menu, then select “Inverter Calculators,” then click “Solar Wire Size Calculator.”

Input the solar array output voltage, maximum amps, wire length, and voltage loss you are willing to tolerate in %, and it will tell you the minimum AWG wire to use and what is the maximum amperage that size will safely carry.

For 100 feet I would go with 10 or 12 ga. for 30 feet, 14 ga. would be fine. I would make my own cables if I was going for the 100 foot length as you will have more wire choices and prices.

Thanks Scott, I appreciate you getting back to me. I’m new to solar generators and want to be sure to get appropriate extension cable.

Another quick question for you Scott. Are you able to connect more than one extension cable together?

Yes, you can connect multiple sets of cables together to get your desired length. That is what I do to keep the size of the cables easily managable for setting up and storage.

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Thanks Scott! When I was starting to think about about longer cables it came to me that logistics in handling, packing and storage might be unwieldy. I appreciate your help!