Re: Battery cables - opinions wanted

Posted by DavidPackard On 2023/9/7 22:03:56

Ken_P

I personally use 2 aught welding cables with soldered ends. I’ve yet found a source for a braded ground strap in the same size, so I’ve done the unspeakable and used the ‘round stuff’ for the positive side. I just bought an aught ground strap that may become a second ground path for the chassis, or perhaps I can make the braded cable obvious, and the round one well hidden.

As for a disconnect switch, I bought, fortunately long before the price went to the moon, an Eaton/Bussmann unit rated at 400/2000 A. I happen to disconnect the positive side, but that was driven by the available ‘under hood’ space and the proximity to the positive terminal. I suspect each of us will have several opinions on which pole to disconnect when the car is in storage. The battery terminals that attach to the battery itself were bought from DelCity, and are made from a brass alloy. The bottom line is the terminal remains in the elastic range when clamping onto the SAE terminal, that is, as soon as the pinch bolt torque is released the terminal is free of the post. Because of this the extra cost of a disconnect switch may not be needed if you are willing to ‘pop’ the cable free of the battery.

I’ve also found that a battery rated between 800 - 900 CCA will provide adequate starting voltage/current if used in conjunction with the above cables. Let’s not forget the other opportunity to undo all of our good intensions, namely the solenoid contacts. I swear I ‘fixed’ a ’54 327 by installing a rebuilt solenoid . . . even though the removed unit did not look all that bad with respect to oxidation/corrosion/pitting. Perhaps I should have soaked the copper washer in solvent for a few days, or used the ultrasonic cleaner.

I agree with Ross, in that when these cars were new and driven regularly 1/0 cables were adequate, but it is an industry that notoriously saved pennies on every part. Ross’s experience aside, I don’t used my hobby cars anywhere nearly as frequent as I would prefer and seem to be presented with a car that hasn’t been used for 3-4 weeks. The self-discharge rate of a battery is temperature dependent, and hot storage will maximize the self-discharge rate (I got that factoid from Harley Davidson). I live in Arizona so it’s an up-hill battle of battery voltage that is less than I would prefer, and an empty float bowl . . . which I refill with the auxiliary fuel pump prior to attempting a start. The garages where the cars are stored does not have electrical service, so for me every little bit of voltage drop is important. Knock on wood, I’ve owned these cars for over 10 years (zero experience below 40F), and have never had a case where the engine didn’t start.

I believe when Georg Ohm published his work he advanced a slightly more complex relationship than we use today, and his contemporaries didn’t completely believe him.

dp