Official wire sizes?

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Will C

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Hi guys,

So I relocated my car battery from under the bonnet to in the boot a few years ago. It’s a project car and been off the road for years. So not really had a thorough opportunity to test if the wire thickness was reliable. Also I cannot remember which size it actually is.

Anyhow I thought I would upgrade the wire size to something more along the lines of which I have seen on factory OEM cars. I had a look online, youtube, google etc and come to the conclusion that 0AWG is what I need. It looks thick. Great, exactly what I’m after it.

So I order 5 metres of 0AWG from ebay and I open the packaging and was surprised as I was expecting it to be a lot thicker. It read 35mm2 on it. I did some googling and every conversion chart I read said that 35mm2 was 2 Gauge and 0AWG is more like 53-55mm2. It looks very similar in size to the cable I used years ago. Maybe slightly slightly larger in diameter.

I messaged the seller and he got back to me saying as per description( my bad I didn’t actually read the description I didn’t think it was necessary ☹️) said that the 0AWG was indeed 35mm2 as per their description.

Basically I’m wondering who is correct here before I message the seller back.

Thanks guys, Will.
 
The table here says 0AWG is about 53mm and the cable you have sounds more like 2AWG

Typical ebay miss selling. Quote him that table and ask for either a refund or replaced with the correct size.
 
Thanks for the response all, I have messaged the seller again regarding the sizes compared to multiple websites/charts that I have linked him.

I have asked if he has 53mm2 in stock, doubt it though. I’m hoping he has and he can exchange it or worst case I send it back for a refund.

Even though that’s what is states in the description I still believe I am not in the wrong as there is evidence against what he states is not what it actually is?

Anyway, will let you all know, thanks.
 
if it states 0AWG and 0AWG is 53mm, and you've received 35mm then its not what's you've bought. unless it says 35mm elsewhere in description but even so, still send it back for refund since its not 0AWG
 
You could just double up the cable you have just bought with the one you fitted a year ago.

I never thought about that.. that may seem like a good idea then.

Will that setup operate as the same as the 0AWG ratings ?
 
I never thought about that.. that may seem like a good idea then.

Will that setup operate as the same as the 0AWG ratings ?

To my understanding, as a general rule 2x 35mm CSA conductors, will give better overall performance characteristics than a single 53mm CSA conductor.

e.g.
If you took the time and effort to remove all of the insulation off the 2x 35mm CSA cables....
Then re-wrapped them back together as a single conductor.. This would be equivalent to a 70mm CSA cable specification. Which is better than a 53mm CSA conductor.

So parallel connection may be less hassle time & effort than trying to get an eBay seller to replace or refund your purchase.

Maybe just use what you have got and move on!
 
To my understanding, as a general rule 2x 35mm CSA conductors, will give better overall performance characteristics than a single 53mm CSA conductor.

e.g.
If you took the time and effort to remove all of the insulation off the 2x 35mm CSA cables....
Then re-wrapped them back together as a single conductor.. This would be equivalent to a 70mm CSA cable specification. Which is better than a 53mm CSA conductor.

So parallel connection may be less hassle time & effort than trying to get an eBay seller to replace or refund your purchase.

Maybe just use what you have got and move on!
Thanks, what would be the best way to re-insulate them to a good standard. Also what if don’t strip them and just run them alongside each other?
 
You could just use 50mm welding cable or 50mm H07, you will find both of these everywhere.. How you planning on terminating the ends??

john..
I don’t have spare welding cable, If I knew I would have received 35mm2 I would have looked into the 50mm welding cable you suggest.

The end under the bonnet will go to a 150A junction box with two smaller positive cables. The cable end in the boot will connect to the battery via a regular battery terminal.
 
The end under the bonnet will go to a 150A junction box with two smaller positive cables. The cable end in the boot will connect to the battery via a regular battery terminal.
I advise a fusible link at the battery. Could save your car from incineration if that cable is ever damaged.
 
0 (1/0)8.30.3353.5
AWGDiameter
(mm)
Diameter
(in)
Square
(mm2
Perhaps confusion between sq mm and actual dia. 0 AWG is 8mm dia and 53.5mm sq. Single copper core rated for 200amps.
 
Well I checked today and It’s actually 16mm2 (70amps) in the car right now hahah 😂Pretty sure that’s not rated enough for a battery cable, especially with a 100amp circuit breaker. Thank god the wiring was fine otherwise…. Don’t know what I was thinking back then……. madness.

I touched the positive battery terminal today when I was at the car and the terminal was slightly warm (i did not have my 100amp circuit breaker installed today), this was ignition on engine off for about half hour while I was doing stuff with the laptop connected to it. Is this because cable only 16mm2 ? Anyone know why it would be slightly warm ?

Either join two together for 51mm2 , not quite sure how i’m going to re-insulate to a high standard.
Or just send back and buy 5 metres of 50mm2 cable for the same price…

Think the latter, thanks all.
 
If the cable is warm you are drawing significant current. If the battery connector is warm you have a poor connection, either cable to connector, or connector to battery. Clean every connecting surface to bright metal then tighten securely.

I'm not sure what you mean about joining and insulating. Every cable end, whether you use one, ore two pieces should be terminated in a matching tubular terminal crimped on. Solder is an acceptable alternative but needs to be very hot and very quick so it doesn't run back up the cable, making the end rigid,
The terminals chosen must have the correct hole for whatever you are bolting them to. For insulation, get some heat shrink sleeve which will also strengthen the joint of cable to terminal. For an example, look how the original starter cable of your car is made.
 
If the cable is warm you are drawing significant current. If the battery connector is warm you have a poor connection, either cable to connector, or connector to battery. Clean every connecting surface to bright metal then tighten securely.

I'm not sure what you mean about joining and insulating. Every cable end, whether you use one, ore two pieces should be terminated in a matching tubular terminal crimped on. Solder is an acceptable alternative but needs to be very hot and very quick so it doesn't run back up the cable, making the end rigid,
The terminals chosen must have the correct hole for whatever you are bolting them to. For insulation, get some heat shrink sleeve which will also strengthen the joint of cable to terminal. For an example, look how the original starter cable of your car is made.
Thanks, like brake lights being on for half an hour? (engine off) I also discovered yesterday my brake light switch somehow broke. I didn’t notice till I was finished and went to disconnect the battery negative.

No I don’t mean that I mean people were suggesting Instead of sending my 35mm2 back and buying larger, another option would be to strip my current 16mm2 and 35mm2 insulation off, join both copper wires to give 51mm2. I’m wondering how I would re insulate that copper cable properly, ie not use red tape or red heat shrink lol.
 
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