I make my own using CAT 8 cable. 24 gauge x 8 strands is 15 awg. 8 x 26 is 17 awg
https://www.wirebarn.com/Combined-Wire-Gauge-Calculator_ep_42.html
I use different colors for +/-, easy to know at either end.
wrap for 3 feet, tape; wrap other direction 3 feet, tape, change direction ....: avoids having to constantly flip the long cable every turn if all wrapped the same direction.
need flat?
cut connectors off, add spades/bananas etc.
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note: check both conductor and connectors for pure copper (you will cut off the connectors), some only the connectors are pure copper