I want wire a permanent extension cable to my car battery charger, so I can
plug it in to my outdoor mains socket and connect it to the battery as
required, with minimum fuss. Struggling to find an appropriate item
though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of thing?
Not sure about that particular one as I worry about the provenance of some
electrical stuff on ebay, and an outdoor connector would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with the
circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a huge
minimum shipping fee (I do have a local Screwfix and Toolstation)

Thanks

--
David

Why not just replace the whole cable, it will probably work out cheaper and you do not have to worry about potential leakage.

Richard

On 22/02/16 08:34, Lobster wrote:
I want wire a permanent extension cable to my car battery charger, so I can
plug it in to my outdoor mains socket and connect it to the battery as
required, with minimum fuss. Struggling to find an appropriate item
though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of thing?
Not sure about that particular one as I worry about the provenance of some
electrical stuff on ebay, and an outdoor connector would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with the
circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a huge
minimum shipping fee (I do have a local Screwfix and Toolstation)

Thanks


The connector is fine.

However the gland may not be terribly effective with flat flex.

Given the battery charger is not waterproof, I'd cut the flex close to
it and joint it there.

Another option is to crimp or solder, heatshrink the joints then put
adhesive lined heatshrink over the whole lot. That will make a
watertight joint.

On 22/02/2016 08:34, Lobster wrote:
I want wire a permanent extension cable to my car battery charger, so I can
plug it in to my outdoor mains socket and connect it to the battery as
required, with minimum fuss. Struggling to find an appropriate item
though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of thing?
Not sure about that particular one as I worry about the provenance of some
electrical stuff on ebay, and an outdoor connector would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with the
circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a huge
minimum shipping fee (I do have a local Screwfix and Toolstation)

Thanks


Presumably the charger itself will be protected from the weather? In
that case - as others have said - simply replace the existing cable with
a much longer one. Then you don't have to worry about waterproof connectors.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On 22/02/2016 08:34, Lobster wrote:

I want wire a permanent extension cable to my car battery charger, so I can
plug it in to my outdoor mains socket and connect it to the battery as
required, with minimum fuss. Struggling to find an appropriate item
though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of thing?
Not sure about that particular one as I worry about the provenance of some
electrical stuff on ebay, and an outdoor connector would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with the
circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a huge
minimum shipping fee (I do have a local Screwfix and Toolstation)

I would just replace the whole flex...

One thing to consider, those small flat flexes are usually only fault
protected by a 13A fuse when they are no longer than about 6'. So if
extending it with something similar, you would need to make sure a
smaller fuse is fitted to the plug. (or use a heavier flex). CPC sell
rubber clad flex by the meter...



--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 22 Feb 2016, John Rumm grunted:

On 22/02/2016 08:34, Lobster wrote:

I want wire a permanent extension cable to my car battery charger, so
I can plug it in to my outdoor mains socket and connect it to the
battery as required, with minimum fuss. Struggling to find an
appropriate item though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of
thing? Not sure about that particular one as I worry about the
provenance of some electrical stuff on ebay, and an outdoor connector
would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with
the circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a
huge minimum shipping fee (I do have a local Screwfix and
Toolstation)

Thanks for the replies

I would just replace the whole flex...

I would but would have to trash the charger in doing so - however it does
make perfect sense to use a simple non-waterproof connector close to the
charger as has also been suggested!

One thing to consider, those small flat flexes are usually only fault
protected by a 13A fuse when they are no longer than about 6'. So if
extending it with something similar, you would need to make sure a
smaller fuse is fitted to the plug. (or use a heavier flex). CPC sell
rubber clad flex by the meter...

Hadn't appreciated that aspect. Actually I'm going to need 17m of flex to
get from my exterior plug to the car. The charger is 60W, and was supplied
with a 3A fuse. What's the implications there?

Basically, I have hitherto been using this charger with a cable reel, which
has an RCD unit at the plug end, meaning that I can't use my exterior
socket as the RCD won't fit into the weatherproof box. Therefore I have to
prat about running the cable reel through a window instead, which is crap
especially overnight or in bad weather (which is usually the case when the
battery needs charging!) Hence my idea for the dedicated extension.


--
David

In article ,
Lobster wrote:
Basically, I have hitherto been using this charger with a cable reel,
which has an RCD unit at the plug end, meaning that I can't use my
exterior socket as the RCD won't fit into the weatherproof box.
Therefore I have to prat about running the cable reel through a window
instead, which is crap especially overnight or in bad weather (which is
usually the case when the battery needs charging!) Hence my idea for
the dedicated extension.

Get (or make) an ordinary extension (not on a reel). If you can't fit an
RCD plug to your outside socket, no worse than plugging in the charger
direct.

But IMHO any outside socket should be RCD protected. Before I changed to
an RCD CU, I had a RCD mounted close to the outside socket for this
purpose. It's rather like an FCU and as well as the RCD has a 13 amp fuse
in it. And can be used to switch off the outside socket.

--
*If you're not part of the solution, you're part of the precipitate *

Dave Plowman London SW
To e-mail, change noise into sound.

On 24 Feb 2016, "Dave Plowman (News)" grunted:

In article ,
Lobster wrote:
Basically, I have hitherto been using this charger with a cable reel,
which has an RCD unit at the plug end, meaning that I can't use my
exterior socket as the RCD won't fit into the weatherproof box.
Therefore I have to prat about running the cable reel through a window
instead, which is crap especially overnight or in bad weather (which is
usually the case when the battery needs charging!) Hence my idea for
the dedicated extension.

Get (or make) an ordinary extension (not on a reel). If you can't fit an
RCD plug to your outside socket, no worse than plugging in the charger
direct.

But IMHO any outside socket should be RCD protected.

Oh, +1

We do have an RCD CU already so the unit on my cable reel is actually
redundant at home - I have this model because I use it at other (non-RCD-
protected) locations.

I just kind of liked the idea of having my charger hard-wired with the
correct length of cable to be able to use it, so I don't need to track down
the extension cable when the car battery's flat. I also have a bit of an
aversion to using extensions with appliances on a permanant basis (hence
the rather large number of mains sockets in my house!)


--
David

In article ,
Lobster wrote:

I just kind of liked the idea of having my charger hard-wired with the
correct length of cable to be able to use it, so I don't need to track down
the extension cable when the car battery's flat. I also have a bit of an
aversion to using extensions with appliances on a permanant basis (hence
the rather large number of mains sockets in my house!)

Personally I have an aversion to any form of flex connector. If I can't
replace the entire flex, I'll stick to a plug and socket.

I really can't see the problem. The charger will have to go under the
bonnet etc if it's likely to get wet. So what's wrong with having a 13 amp
plug and socket from an extension there too? It's what I do.

--
*Where do forest rangers go to "get away from it all?"

Dave Plowman London SW
To e-mail, change noise into sound.

On 23/02/2016 23:49, Lobster wrote:
On 22 Feb 2016, John Rumm grunted:

On 22/02/2016 08:34, Lobster wrote:

I want wire a permanent extension cable to my car battery charger, so
I can plug it in to my outdoor mains socket and connect it to the
battery as required, with minimum fuss. Struggling to find an
appropriate item though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of
thing? Not sure about that particular one as I worry about the
provenance of some electrical stuff on ebay, and an outdoor connector
would be right up there.

My charger has a two-core, flat-profile flex - will that work OK with
the circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a
huge minimum shipping fee (I do have a local Screwfix and
Toolstation)

Thanks for the replies

I would just replace the whole flex...

I would but would have to trash the charger in doing so - however it does
make perfect sense to use a simple non-waterproof connector close to the
charger as has also been suggested!

Is it welded together then?

One thing to consider, those small flat flexes are usually only fault
protected by a 13A fuse when they are no longer than about 6'. So if
extending it with something similar, you would need to make sure a
smaller fuse is fitted to the plug. (or use a heavier flex). CPC sell
rubber clad flex by the meter...

Hadn't appreciated that aspect. Actually I'm going to need 17m of flex to
get from my exterior plug to the car. The charger is 60W, and was supplied
with a 3A fuse. What's the implications there?

3A flex is typically 0.5mm CSA core size, which is say 39mOhm/m. You are
talking about a L to N short at the end of the cable of length 17m, so
that's a round trip resistance of about 1.32 ohms. Add that to the 1.5
ohm max loop impedance for a ring protected with a B32 MCB, and it gives
you 2.82 ohms total. So your prospective fault current could be as low
as 230 / 2.82 = 81A

That will open a 13A fuse in about a second worst case (i.e. too slowly
for a portable appliance). Just to add insult to injury you can do a
quick with the adiabatic equation: s = sqrt( i^2 t ) / k where k is 115
for PVC clad cables.

s = sqrt( 6561 ) / 115 = 0.7mm^2

Would suggest that the flex may burst into flames before the fuse has
got round to doing its thing!

With a 3A fuse however you should be safely down in the 0.1 sec or less
opening time, and hence only need about 0.2mm of CSA to survive for that
long.

(having said that, you don't have to use 0.5mm^2 flex, you could go up a
size anyway)




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On Wednesday, 24 February 2016 22:07:39 UTC+1, John Rumm wrote:
On 23/02/2016 23:49, Lobster wrote:
On 22 Feb 2016, John Rumm grunted:

One thing to consider, those small flat flexes are usually only fault
protected by a 13A fuse when they are no longer than about 6'. So if
extending it with something similar, you would need to make sure a
smaller fuse is fitted to the plug. (or use a heavier flex). CPC sell
rubber clad flex by the meter...

Hadn't appreciated that aspect. Actually I'm going to need 17m of flex
to get from my exterior plug to the car. The charger is 60W, and was
supplied with a 3A fuse. What's the implications there?

3A flex is typically 0.5mm CSA core size, which is say 39mOhm/m. You are
talking about a L to N short at the end of the cable of length 17m, so
that's a round trip resistance of about 1.32 ohms. Add that to the 1.5
ohm max loop impedance for a ring protected with a B32 MCB, and it gives
you 2.82 ohms total. So your prospective fault current could be as low
as 230 / 2.82 = 81A

Follow you so far (I don't have the resistance of various cables memorized,
but I can see how to google for it; similarly the 1.5 Ohm feels like
something that I ought to be able to find in the IEEE regs and probably lots
of other places).

That will open a 13A fuse in about a second worst case

But I don't know where to get that information from. Is it another
table in the regs?

Or is it arcane knowledge that you are only allowed
to know once accepted in the secret Electricians Society.

In article , Martin
Bonner wrote:
On Wednesday, 24 February 2016 22:07:39 UTC+1, John Rumm wrote:
On 23/02/2016 23:49, Lobster wrote:
On 22 Feb 2016, John Rumm grunted:

One thing to consider, those small flat flexes are usually only
fault protected by a 13A fuse when they are no longer than about 6'.
So if extending it with something similar, you would need to make
sure a smaller fuse is fitted to the plug. (or use a heavier flex).
CPC sell rubber clad flex by the meter...

Hadn't appreciated that aspect. Actually I'm going to need 17m of
flex to get from my exterior plug to the car. The charger is 60W,
and was supplied with a 3A fuse. What's the implications there?

3A flex is typically 0.5mm CSA core size, which is say 39mOhm/m. You
are talking about a L to N short at the end of the cable of length
17m, so that's a round trip resistance of about 1.32 ohms. Add that to
the 1.5 ohm max loop impedance for a ring protected with a B32 MCB,
and it gives you 2.82 ohms total. So your prospective fault current
could be as low as 230 / 2.82 = 81A

Follow you so far (I don't have the resistance of various cables
memorized, but I can see how to google for it; similarly the 1.5 Ohm
feels like something that I ought to be able to find in the IEEE regs and
probably lots of other places).


[Snip]

IEEE are American, presumably you ment IET (as it is now) or even BS7671.

--
from KT24 in Surrey, England

On 25/02/2016 15:30, Martin Bonner wrote:
On Wednesday, 24 February 2016 22:07:39 UTC+1, John Rumm wrote:
On 23/02/2016 23:49, Lobster wrote:
On 22 Feb 2016, John Rumm grunted:

One thing to consider, those small flat flexes are usually only fault
protected by a 13A fuse when they are no longer than about 6'. So if
extending it with something similar, you would need to make sure a
smaller fuse is fitted to the plug. (or use a heavier flex). CPC sell
rubber clad flex by the meter...

Hadn't appreciated that aspect. Actually I'm going to need 17m of flex
to get from my exterior plug to the car. The charger is 60W, and was
supplied with a 3A fuse. What's the implications there?

3A flex is typically 0.5mm CSA core size, which is say 39mOhm/m. You are
talking about a L to N short at the end of the cable of length 17m, so
that's a round trip resistance of about 1.32 ohms. Add that to the 1.5
ohm max loop impedance for a ring protected with a B32 MCB, and it gives
you 2.82 ohms total. So your prospective fault current could be as low
as 230 / 2.82 = 81A

Follow you so far (I don't have the resistance of various cables memorized,
but I can see how to google for it; similarly the 1.5 Ohm feels like
something that I ought to be able to find in the IEEE regs and probably lots
of other places).

1.5 is actually a slight over estimate, BS7671 has 1.44 for a B32 MCB:

http://wiki.diyfaq.org.uk/index.php/...Loop_Impedance

You should also find it in the on site guide and a number of other
places. You could also work it out from first principles by looking at
the response curves for the MCB:

http://wiki.diyfaq.org.uk/images/d/d...e-MCBTypeB.png

(or for that matter, just remember that for a type B device the fault
trip current will be 5 x In (10x for a type C and 15x for a type D). So
5 x 32 = 160A)

Since we know the current needed to guarantee "instant" opening of a B32
MCB (i.e. using its magnetic fault detection response rather than its
overload thermal response) is 160A. A quick application of V = IR, so
230 = 160 R, 230 / 160 = 1.44 Ohms.

That will open a 13A fuse in about a second worst case

But I don't know where to get that information from. Is it another
table in the regs?

That one is not in the regs, but you will find it in BS1362, and also he

http://wiki.diyfaq.org.uk/index.php/...ins_Plug_Fuses

(click picture for larger size)

Or is it arcane knowledge that you are only allowed
to know once accepted in the secret Electricians Society.

There are loads of bits of obscure information tucked away in various BS
docs. Alas they are not that well publicised and not always easy to get
hold of without paying silly money for. (local library is the best bet -
some also allow free online access to library card holders via the BSI
web site)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

In article ,
Lobster wrote:
I want wire a permanent extension cable to my car battery charger, so I
can plug it in to my outdoor mains socket and connect it to the battery
as required, with minimum fuss. Struggling to find an appropriate item
though.

I think http://www.ebay.co.uk/itm/400985859386 may be the sort of thing?
Not sure about that particular one as I worry about the provenance of
some electrical stuff on ebay, and an outdoor connector would be right
up there.

My charger has a two-core, flat-profile flex - will that work OK with
the circular rubber glands these things usually have?

Any suggestions very welcome - preferably not from a supplier with a
huge minimum shipping fee (I do have a local Screwfix and Toolstation)

Given you can't leave the charger in the rain, etc, why do you need a
waterproof connector? Use an extension lead and just put the ordinary 13
amp one under the bonnet or boot along with the charger. You then have the
extension lead for other things if needed.

Another way you might consider. Given how cheap those Lidl etc chargers
are, I've built one into my old Rover. Alongside the spare wheel in its
underfloor space, as there's room there and its protected from being
bashed. But it could go anywhere. I used a waterproof mains connector
(Buccaneer) fitted to the panel under the rear bumper, so nearly invisible.

--
*Acupuncture is a jab well done*

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
Given you can't leave the charger in the rain, etc, why do you need a
waterproof connector? Use an extension lead and just put the ordinary
13 amp one under the bonnet or boot along with the charger. You then
have the extension lead for other things if needed.

I'm glad you asked that as it's what I do

--
Robin
reply to address is (meant to be) valid