Wire size hooking up a dc-dc charger

[allj]

Hello,
I have a Renogy 20A DC-DC charger. I am a novice about rv electricity. A few questions.
1-The manual says the minimal gauge is 10 awg for my length. Would it be better to put the max of 4 awg instead?
2- Does the strand type matter - i.e. can I use a welder wire or thicker strands?
3- Can I attach the input wire to the DC charger to the alternator wire that is attached to my solenoid (solenoid no longer needed with the charger)?
4- If 3 then should I use a battery junction post to connect it?
Thank you for taking the time to answer this. It's much appreciated!
Alan

 

[Bigblockyeti]

20A for short runs can use 12ga wire, longer and 10ga is better + plus will allow the use of a 30A fuse which 12ga will not. There's no advantage to going with larger wire unless you're specifically planning on a more powerful charger in the future. Larger wire will only add more cost and weight. The strand type doesn't matter, there would be no advantage to using something like welding lead as they have a high strand count only because they're being constantly moved thus needing to be flexible.

 

[allj]

Thanks Bigblockyeti,
Really appreciate your info! With your help I'm going to feel comfortable taking this on. Can I use an inline auto breaker instead of an ANL fuse? This way I can trip it as a shutoff switch if needed. Alan

 

[Bigblockyeti]

I think a breaker would be a great subsitute for a fuse, that's what I did for my electric trailer brake controller.