Hi m8 did you say
Screenshot 2024-04-21 at 14-36-27 Flexible battery and starter cable in various sizes suitable for 12V and 24V automotive marine and solar power applications.png
I got this
https://www.ebay.co.uk/itm/124285520044?var=425170567732
Same but 300/40 and a lot cheaper!
Provided you solder and don't rely on just a crimp, that'll do fine. I've put this up before:
How to clean copper-cable.
You'll want to do this to get solder to flow into a joint. More so with heavy charge/ battery cables. You will fail to solder without clean wire. Solder will just 'sit' on the wire rather than coat and flow.
Mix two solutions, one is regular table salt and vinegar. Any vinegar will work. It's the acidity and corrosiveness of the salt and vinegar together you want. The other solution is Sodium Bicarbonate, or baking soda, and water. This used to neutralise the corrosive properties of the other solution; to further clean the wires.
Strip the wires to be cleaned.
Get 2 containers, one for each solution. Vials are good.
1 tablespoon of raw salt, fill up the rest with vinegar. Stir. Put as much salt in the vinegar as will dissolve.
1 tablespoon of Sodium Bicarbonate, (baking soda) and add it to the other container. Fill the rest with water. Stir. Add more baking soda until cloudy. The amount is not important, as long as it is alkaline to cancel the acid of the vinegar solution.
Put the stripped end of the wire in the vinegar solution, and stir the solution with the wire. Any wire you want cleaned needs to be under the solution. Movement of the wire in the liquid speeds up the process.
Step 6: After 2 minutes or so, the wire will look very shiny and new in the vinegar solution. The acid and salt in the solution is etching away the oxides, exposing the bare metal. Make sure the metal is uniformly shiny. Leave it in longer if it is not perfectly clean throughout.
Step 7: Once the wire is satisfactorily clean, remove the wire from the vinegar, and plunge it into the baking soda solution to neutralise the acid's corrosive properties. If the wire was exposed to the air, without neutralising the acid first, it would quickly corrode again. The baking soda keeps it clean and shiny. Swish the wire around in the baking soda water for about 10 seconds. You are done. Shiny new wire ready for soldering, and conducting.
Outside of the LR bubble, you solder heavy stuff. Use rosin or plumber's flux for the heavy stuff. Shrink-wrap.
Accepted practice on most modern cars for 30+ years. Inside the LR Bubble you'll hear words of 'crimp'. These words are not minded to application. Well enough for low current, stranded wire. To and from a battery, to 'crimp' is hogwash/ a lash-up/ for Whoopsies - or all three. Cars didn't start in the 60s/70s. Crimp to heavy current cable was one of the reasons.