I use #1 for a run from the trunk to the solenoid on my cars. Little extra cost = little voltage drop = never a worry.
might depend on few variables, like what engine it is, 6v or 12v, how long the run is, etc. 4 gauge might work on a short run with a small engine, 00 might be needed for a wild high compression big block with a long run.
I use 2 gauge, but my battery is only 5 feet from the starter. You didn't say what kind of car. The longer the cable the bigger gauge required. .bjb
It's a 1940 merc..small block ,12 volt. Guessing a 12 ft distance from trunk location to starter terminal.
At least 1/0, 2/0 would be better. Bigger yet if it's a hard-to-start application like a big high-compression or blower motor.
What side is best when putting a battery in the trunk? Most of that I see are mounted on the p***enger side and did this to my last car , but these pictures makes me re-think doing that on the next build. It won't be an x frame but that p***enger side slick looks planted pretty good.
I used double ought on my last setup. 12V and right behind the cab of a C10. May have been overkill. LOL
I recently upgraded my battery cable from trunk to solenoid due to voltage drop. It starts each and every time now when hot.
I ran 1/0 batt cable from my trunk to the side of firewall (20') on my '54 Ford. Ran the positive cable below the decklid, over the wheelhouse and through the rocker panel to a power post. Check these guys out. batterycablesusa.com Great prices, quality products and a $4 flat rate shipping charge!
It was done on the p***enger side in the "Hot" factory cars back in the day for traction purposes. And I did the same because the starter is on that side using welding cable because it was very flexible and easier to run along the frame. But with todays tires and track prep it doesn't much matter anymore.
My 40 Ford sedan had a plate above the rear axle on the p***. side; I removed it and it was a good hole to run the OO cables through to the battery.
I always use at least 1/0 and often 2/0. But you need to be sure you're also using the extremely fine strand battery cable, and not the co**** strand wire. The co**** strand wire does not have the same high ampacity of the very fine strand wire, so wont have the same high current rating.
Good advice. This is why I like welding lead. One thing that is going to piss the uneducated off but I am going to throw it out there anyway. The current does not run though the wire it runs along the surface of the wire. The more stands you got the more surface area you got. Now take that or leave it it is free information.
My battery is in the 'trunk' of my '36 Willys, right in front of the spare tire bump. I run 2/0 welding cables, one positive to the starter, and one negative that bolts to the starter mount. I run the negative cable 'cause 99.99999% of car electrical problems are ground problems.