Battery cable temperature rating only 70 degrees C?

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syvictoria

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It's come to my notice that Oceanflex 35mm2 tinned battery cable seems to only be rated to 70 degrees C. Oceanflex's smaller cables are rated to 105, as is the 2AWG ancor battery cable that I also have. This would therefore appear to be poorly spec'd in comparison, especially given that it is connected to, and routed close by, the engine! Is a 70 degrees C rating deemed sufficient and fit for purpose? As always, thanks in advance!
 
pvb said:
According to Furneaux Riddall, who are generally trustworthy, Oceanflex 35mm2 is "Suitable for use at temperatures from -40ºC to 105ºC with excursions up to 120ºC".

https://www.furneauxriddall.com/aca...-2-AWG-240-amps-PER-METRE-CM35_PER_METRE.html
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Unfortunately I think that's generic information, and not specifically correct for that product. My cable is stamped 70 degrees C (unfortunately I'm not at the boat at present and so I can't provide a photo) and Koyaycat's website states the lower figure:

https://kojaycat.co.uk/Cable-Tinned-Battery-Marine-Grade/35mm2-Tinned-Copper-Battery-Cable

I had just assumed that this would be spec'd the same as other 'quality' tinned cable...
 
syvictoria said:
Unfortunately I think that's generic information, and not specifically correct for that product. My cable is stamped 70 degrees C (unfortunately I'm not at the boat at present and so I can't provide a photo) and Koyaycat's website states the lower figure:

https://kojaycat.co.uk/Cable-Tinned-Battery-Marine-Grade/35mm2-Tinned-Copper-Battery-Cable

I had just assumed that this would be spec'd the same as other 'quality' tinned cable...
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The manufacturers of Oceanflex say 105ºC, why not have a word with them?

https://www.automarinecables.com/cables/details.cfm?id=181

I suspect you've been sold flexible battery cable which isn't actually Oceanflex. Auto Marine also make a flexible battery cable which is only rated to 70ºC. Have a look at their cable catalogue, page 11...

https://www.automarinecables.com/userfiles/Cat 18-19/amc-product-catalogue-2018-19-cable.pdf
 
Mine too. For that reason, when I rewired the 12v on our boat I kept all the wiring in the engine compartment as is with evidently higher temp cable.
 
syvictoria said:
The catalogue actually shows my tinned cable on page 20 as 70C. However, if this is good enough for PaulRainbow and Hoolie, well, I suppose it must be good enough for me! :)
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And on p20 it says to refer to p17 for specifications, where it then says 105ºC! Rather a poor show from a British manufacturer.
 
If you cable is getting anywhere near 70C you definitely need a bigger cable but the temperature rating also relates to the maximum ampacity of the cable.. The same size cable can manage increasing amounts of current at increasing temperatures.. As you can see here..https://www.bluesea.com/resources/529/AllowableAmperageinConductors-WireSizing_Chart

Do your load calculations and make sure the cable is suitable and go to the next size up if you are close to reaching the limit of the cable.. Also remember that the length of the cable is important to factor as well..
 
wipe_out said:
If you cable is getting anywhere near 70C you definitely need a bigger cable but the temperature rating also relates to the maximum ampacity of the cable.. The same size cable can manage increasing amounts of current at increasing temperatures.. As you can see here..https://www.bluesea.com/resources/529/AllowableAmperageinConductors-WireSizing_Chart

Do your load calculations and make sure the cable is suitable and go to the next size up if you are close to reaching the limit of the cable.. Also remember that the length of the cable is important to factor as well..
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Thanks for the advice. I have already gone up one size as 25mm2 would have been sufficient according to calculations. I was simply surprised that the spec. of the offending cable was less than all of the others I've installed, battery or otherwise.
 
Hoolie said:
As I suggested earlier, this 70C cable will not be suitable for your engine compartment unless it's really well ventilated
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Ah! I misread your earlier post, sorry. I thought you and PaulRainbow had agreed that 70C was sufficient. I think I will be replacing the cable when I can as it's a bit of a worry now, and hence my post. :mad:

It's a pity that Ancor products are quite hard to come by in the UK. We have so little choice, especially if you want to buy in person (how old fashioned!!! :rolleyes:). If it doesn't come from ASAP/Aquafax, it nigh on doesn't exist...
 
Hoolie said:
As I suggested earlier, this 70C cable will not be suitable for your engine compartment unless it's really well ventilated
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From what I understand a 35mm2 cable with a 75C rating is good for up 130A in the engine room as a single cable and about 90A in a bundle..
 
wipe_out said:
From what I understand a 35mm2 cable with a 75C rating is good for up 130A in the engine room as a single cable and about 90A in a bundle..
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Yes, and with a 67C rating only a little over 81A in the engine room as a single cable, that makes my 70C cable somewhere in between 81A and 130A - much less than I had thought (added to which, I have a bundle of two!). Grrrr... shame on you Oceanflex. My fault I suppose for not checking properly. With there seemingly being just one viable product option available in tinned, I'd just assumed that the whole Oceanflex range was rated to 105C as was the 1.5mm2 three core I'd purchased previously.

I'm now also wondering about the flat 1.5mm2 twin as I've just spotted that this doesn't have a temp suitability range on the ASAP website. The round does and that states 105C. I'll have to check my cable assuming that it's stamped. This should be okay at a lower temp rating anyway. It shouldn't be this hard, especially when 'marine' consumers have to pay through the nose for everything anyway. Sorry, rant over... :apologetic:
 
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syvictoria said:
YI'd just assumed that the whole Oceanflex range was rated to 105C as was the 1.5mm2 three core I'd purchased previously.

I'm now also wondering about the flat 1.5mm2 twin as I've just spotted that this doesn't have a temp suitability range on the ASAP website.
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The Oceanflex website (if it can be believed) says "Twins and multicore PVC sheathed at 70ºC", so is your 3-core stamped with 105ºC?
 
I would have thought 70C was fine anyway. That is hot enough to burn your skin and there is no where in my engine space that is anywhere near that hot except actually touching the engine.

Even if it were to get that hot it would only be an issue if you were running the cable fully loaded for a period of time and that is highly unlikely.
 
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bedouin said:
I would have thought 70C was fine anyway. That is hot enough to burn your skin and there is no where in my engine space that is anywhere near that hot except actually touching the engine.

Even if it were to get that hot it would only be an issue if you were running the cable fully loaded for a period of time and that is highly unlikely.
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Sadly my cable does run very close to the engine - it's practically unavoidable in such a small space and the engine connections are, naturally, on the wrong side! Also I have a 70A alternator which I guess will be working hard at least some of the time. (If you've seen my other recent posts, I also have an engine which overheats!!!!! Although at least now only if it's ran for over 1.5hrs!)
 
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