A couple of options for stranded wire with silicone insulation

I recently bought a couple of types of silicone-insulated wire, 8 and 12 AWG. I wasn't planning to write about them, but I liked the wires so much that I decided to put together a short review.

The story behind the purchase is a little unusual. I’d had some money sitting in my Banggood BGpay account for a long time. At first I wanted to buy something else, but then it turned out that the “pay the difference” option required an additional payment of at least $100. So I had to find something to buy before the money went to waste. Since I’m gradually putting together a couple of electronic loads, I decided to get some power cables for them. Or maybe for power supplies instead—it doesn’t really matter.

There were other lots that would have been a better deal for me, but I was literally a few cents short. I’ll show you everything I managed to choose today.
Shipping to my location costs extra, but the shipping charges for the two lots aren’t added together. It seems shipping to Russia is free. My total came to $12.61.
Banggood really managed to surprise me, though: I placed the order on December 14, and the package was at my door just 10 days later.




I’ll start with the 12 AWG cable, or 3.3 mm² by our system. I really dislike the American wire-gauge system, where everything is “backwards” and the gauge is based not on cross-sectional area but on the number of times the wire is drawn through a die. Though for stranded wire, the total cross-sectional area of all the strands is used.

It comes as two 1-meter lengths, one black and one red, neatly packed in a labeled bag. It costs $4.49 before shipping — link.
The same lot also offers sizes from 12 to 20 AWG.


The lengths are a little over a meter, with the red piece being longer. The insulation diameter is 4.6 mm. The only markings are the wire gauge and a maximum temperature of 200 degrees. The wire is very flexible.


There are lots of strands, twisted together into a single bundle. They’re a little stiff and even tend to spring back.


The resistance of the 1-meter lengths is about 5 mΩ, or 5 Ω per kilometer.


The second cable is thicker: 8 AWG, or about 8.4 mm². This lot also comes with two 1-meter lengths in different colors, but naturally costs more: $7.32 for a 1+1 m lot — link.
The page also offers other sizes, with a wider selection from 8 to 30 AWG.

This one comes in a plain bag with a barcode.


The length is almost exactly 1 meter, although I didn’t straighten the wire out completely. The insulation diameter is 6.6 mm.
The markings are the same as on the previous cable: wire gauge and temperature. The cut ends of the strands looked a little oxidized.


There are even more strands here, twisted into two bundles, the so-called “core” and “sheath.” Most likely, they’re twisted in opposite directions to keep the cable from twisting as much.
This cable is also very flexible—and given its cross-section, it’s really very flexible. The strands are also quite stiff, which even made me wonder whether they were copper. Also, when I stripped 8 ends with a knife, I didn’t nick a single strand.


The measured resistance of the 1-meter lengths (99 cm, to be exact) is about 2 mΩ, or 2 Ω per kilometer.


Resistance.
Measuring the resistance of stranded cables, especially very flexible ones, isn’t particularly convenient, so just to be safe I double-checked by connecting the wire to a current source and measuring the voltage drop across it.
Using this method, I got 5.1 mΩ for the 12 AWG wire and 2.25 mΩ for the 8 AWG wire.


So, using the two measurement methods, I got 5–5.1 mΩ for the 12 AWG wire and 2–2.25 mΩ for the 8 AWG wire. Let’s check the table: it says that wires with the same cross-sectional areas should have a resistance of 5.21 and 2.06 Ω per kilometer, or mΩ per meter, respectively.

No issues with the resistance—it’s right on spec.


Insulation.
I did two tests. First, I put the wire in the freezer for 7 hours. The measured temperature was -18 degrees. When I took it out, I couldn’t notice any difference in flexibility compared with how it felt at room temperature. Maybe there was a difference, but subjectively it felt the same. I couldn’t think of a way to show this in a photo.

Testing its response to heat was easier. I took a soldering iron set to 340 degrees (that’s just where it happened to be set), stretched some insulation offcuts over the tip, and heated them for about 10 minutes each.


The only difference from the pieces I didn’t heat was some rosin and solder residue that got inside the insulation from the tip. They may have darkened a little, too. Even though the temperature was almost twice as high as specified, the insulation remained just as flexible.


To put any doubts about the steel to rest, I checked with a magnet. Neither wire is magnetic at all.


So, we have two wires with:
1. Resistance that matches the table
2. Insulation that doesn't melt when touched with a soldering iron
3. Insulation that doesn't go stiff in the cold
4. Flexible wires, even with their fairly large cross-section.
5. Strands that aren't magnetic.

All of this was actually a bit unexpected for me, like in that joke: I know I'm being ripped off, but I can't figure out where...

All in all, I recommend buying these wires if the price works for you. I found them on AliExpress, but for buyers in Russia it worked out cheaper to buy them from Banggood because shipping was free. For Ukraine, the price was about the same. I didn't check other countries.

There was also a more convenient listing for me, but unfortunately it was just a few cents over my budget. I think it had 1.5 m lengths of 12 AWG wire.
While searching, I came across listings for wires in a single color. Interestingly, the wire with black insulation cost more...

That's all for today. I hope you found it useful.