As long as you are comparing the same style of lug (flared vs power), then the main difference is marine lugs are tinned coated and usually made of thicker copper - particularly the flat part that makes the electrical contact with the battery terminal.

You can get thick copper automotive lugs, but they aren't that cheap. As for tin plating, this is often desirable, but not always necessary if you use a quality dielectric grease like No-Ox-ID between the mating contacts. A few times we've been in places with no marine supply stuff, but good quality welding supplies, and I've used non-tinned welding cable lugs with no issue on the boat.

I don't know where you are shopping, but here is a high-quality 4/0 lug for $7.50. It is about as expensive as they come, and lugs for smaller wire sizes are considerably less - how much money are you trying to save? https://www.amazon.com/Burndy-YA28-...40&pf_rd_r=NC4YRMEE0RBTC3A8H2XS&pid=5vWwO5H&qid=1684615798&s=industrial&sr=1-16

2/0 for $4.50 each: https://www.amazon.com/Ancor-Tinned-Copper-Lugs-AWG/dp/B000NHZYQU?th=1&psc=1

Mark

 

I don't know where you are shopping, but here is a high-quality 4/0 lug for $7.50. It is about as expensive as they come, and lugs for smaller wire sizes are considerably less - how much money are you trying to save?

My first quick search on Amazon found this - $22.75:

SELTERM 15pcs 2/0 AWG 3/8" Stud UL Marine Grade Battery Terminal Connectors Tinned Copper Battery Cable Lugs 00 Gauge Wire Connectors Electrical Battery Cable Ends Ring Terminals Tinned Copper Lugs

I'm wiring up an electric outboard in the basement, in preparation for installation on my boat, and found the ring lugs wouldn't fit over the screw terminals on the battery monitor's shunt. I was thinking about my alternatives, one of which was cutting off the existing lugs and crimping on new.

Of course, I don't have lugs, crimpers, heat shrink, etc., and was wondering about what I could pick up locally today.

Auto parts aren't only cheaper, they're closer. The nearest West Marine is an hour's drive.

I've decided on an alternative approach, and won't be recrimping the cables, but understanding is never wasted.

Thanks.

 

Around 20,000 hours under power in my log now, Never had anything but automotive lugs and never had an issue or corrosion. ABYC makes no comment on the issue.

 

You need crimpers with dies that match the lugs you have. Not all lugs of the same cable size have the same wall thickness. Different wall thickness need different dies. If the brand of the lug is the same as the brand of the crimp tool, you are likely OK, but some brands have more than one grade, so brand alone is not a 100% guarantee