# 40 amp + cable - where to buy?



## ched999uk (Jan 31, 2011)

Going to add a second battery and have the box, clamps and fuses lined up but having difficulty finding 40 amp cable locally. Probably 35 amp cable would be fine as the fuse would be 30amp. 
Ideally trying to get some locally (Blackpool) and don't really like the idea of paying for Oxygen Free Copper cable from Maplins at £4.19 a meter. Halfords only seem to go up to 27amp.

Any ideas what sort of shop might have some 30-40 amp cable?

Cheers


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## spatz1 (May 19, 2011)

just buy a set of cheap long jump leads and cut the clamps off...

mine were a fiver ! ( 65 amp cable )


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## clive1821 (Mar 27, 2010)

uuumm thats a good bit of lateral thinking I must say well done..... or something like this as a second idea...

http://cgi.ebay.co.uk/HIGH-QUALITY-...al_Components_Supplies_ET&hash=item3cafb18764


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## mishmash (Dec 11, 2010)

I have just done this job and got mine off ebay . Could not find any local after two days of searching.
http://cgi.ebay.co.uk/40-AMP-POWER-...icle_Parts_Accessories_ET&hash=item45fb1b2308
Came in a few days. Hope this helps

Martin


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## sallytrafic (Jan 17, 2006)

80 or 100 amp meter tails City Electric, Neweys or any other electrical retailers check you local yell.


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## ched999uk (Jan 31, 2011)

clive1821 said:


> uuumm thats a good bit of lateral thinking I must say well done..... or something like this as a second idea...
> 
> http://cgi.ebay.co.uk/HIGH-QUALITY-...al_Components_Supplies_ET&hash=item3cafb18764


Thanks. I was trying to avoid delivery as I would like to fit the battery before Friday so it might not get here in time.

I did find this company selling same sort of cable by the meter at £0.96! http://www.rawcomponents.co.uk/cabl...re/red-4mm-thinwall-multi-stranded-cable.html


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## ched999uk (Jan 31, 2011)

spatz1 said:


> just buy a set of cheap long jump leads and cut the clamps off...
> 
> mine were a fiver ! ( 65 amp cable )


Nice idea, I have a few 'cheapy' shops just round the corner from me.
Thanks.


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## sallytrafic (Jan 17, 2006)

One of the problems with cheap cable used for budget jump start cables is the insulation. It doesn't need to meet normal wiring standards of a fixed installation. If called upon to meet the current capacity of the copper for any length of time then the insulation might melt, give off noxious gasses or catch fire. I would avoid putting it in your expensive motor home.


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## ched999uk (Jan 31, 2011)

sallytrafic said:


> One of the problems with cheap cable used for budget jump start cables is the insulation. It doesn't need to meet normal wiring standards of a fixed installation. If called upon to meet the current capacity of the copper for any length of time then the insulation might melt, give off noxious gasses or catch fire. I would avoid putting it in your expensive motor home.


Thanks for the advice.

If I do use 'cheapy' jump leads I will ensure the conductors are 6mm (50A) and I will fuse it both ends at 30amp. So that way they should not be able to get even mildly warm even in a short circuit situation.

Thanks very much for the warning.


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## sallytrafic (Jan 17, 2006)

ched999uk said:


> sallytrafic said:
> 
> 
> > One of the problems with cheap cable used for budget jump start cables is the insulation. It doesn't need to meet normal wiring standards of a fixed installation. If called upon to meet the current capacity of the copper for any length of time then the insulation might melt, give off noxious gasses or catch fire. I would avoid putting it in your expensive motor home.
> ...


Good thinking. I take it you aren't expecting a charge of more than 30A.

Note with such an arrangement the volt drop across the fuses will unbalance the charge a bit with less going to the remote battery. To ensure that it's not some would advocate putting the positive lead from the charger to the new battery but IMO that isn't really necessary nor often practicable.


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## Techno100 (May 8, 2010)

Get what you pay for
THIS stuff is top drawer


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## ched999uk (Jan 31, 2011)

Techno100 said:


> Get what you pay for
> THIS stuff is top drawer


Very true. Copper is expensive, so thick conductors cost.

This place sells 10mm2 at £2.04 per meter. The insulation doesn't look as thick but we are only talking about 12v and it does pass the British Standard.
http://www.rawcomponents.co.uk/cabl...e/red-10mm-thinwall-multi-stranded-cable.html


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## Techno100 (May 8, 2010)

I prefer the dearer stuff, you can hit it with a hammer and the insulation will absorb it. I don't use fuses with this cable.
I use crimped ends and bolt them to my 8mm threaded terminals.

"The specification of the outer is the most important factor for reliability and long life along with its flexibility"

This type of cable is used in UPS and emergency lighting battery banks


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## LittleGreyCat (Jun 22, 2008)

ched999uk said:


> Going to add a second battery and have the box, clamps and fuses lined up but having difficulty finding 40 amp cable locally. Probably 35 amp cable would be fine as the fuse would be 30amp.
> <snip>
> 
> Cheers


Looking in my Durite catalogue I see a fuse rated at 30 amp continuous, 60 amp blow.

This makes me wonder if the fuse would protect the 35 amp cable if the load was 40 amp continuous.

Should you not rate the cable somewhat higher than the fuse?
At least to the 'blow' rating of the fuse?

Or is 35 amp cable rated in a similar way to the fuse i.e. 35 amp continuous 70 amp peak?

Oh, and given "volts x amps = watts" are you happy that your peak load will be less than 360 watts?

I note that my Hymer has a 50 amp fuse on the earth side of the leisure battery, which suggests a maximum load of 600 watts which would comfortably allow me to use a modest inverter.

Cheers

LGC

P.S. if one or more of these fuses protecting the second battery blow, how do you tell until you find your battery capacity below expected?


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## teemyob (Nov 22, 2005)

*Blackpool*



sallytrafic said:


> 80 or 100 amp meter tails City Electric, Neweys or any other electrical retailers check you local yell.


If you can get to me or are passing, I have plenty of meter 100amp tail cable, double insulation. You can have a few metres for FREE.

TM


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## ched999uk (Jan 31, 2011)

LittleGreyCat said:


> ched999uk said:
> 
> 
> > Going to add a second battery and have the box, clamps and fuses lined up but having difficulty finding 40 amp cable locally. Probably 35 amp cable would be fine as the fuse would be 30amp.
> ...


Good points.

I would only have used 35 amp cable (fused at 30 amp) provided the 35 amp cable was rates continuously.

The reason for the 30 amp fuse is actually just to protect the cable in case it shorts out. Hence you need 2 fuses one as close to each battery terminal as possible.

I have installed the battery, well in the end I installed 2 batteries with 100amp continuous cable with 4 x 60 amp fuses.

Thanks for your advice.


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