Battery cable mid-way clamp-on terminals?

[prv]

I have in mind a kind of terminal which could be fitted to the middle of a heavy battery cable, without cutting it. You'd run a knife round to remove a short length of insulation, then assemble the fitting around the exposed copper and do up a couple of bolts to clamp it in position. There would be a ring, stud, or similar terminal onto which you could then bolt another cable.

Obviously an alternative would be to cut the cable, crimp on two lugs, and put them with the new cable onto a stud. Or I could probably build something myself that would clamp on. But I'd like to know if anybody's come across such a thing off the shelf, and has a name to search for.

Cheers,

Pete

 

[Bilgediver]

I have in mind a kind of terminal which could be fitted to the middle of a heavy battery cable, without cutting it. You'd run a knife round to remove a short length of insulation, then assemble the fitting around the exposed copper and do up a couple of bolts to clamp it in position. There would be a ring, stud, or similar terminal onto which you could then bolt another cable.

Obviously an alternative would be to cut the cable, crimp on two lugs, and put them with the new cable onto a stud. Or I could probably build something myself that would clamp on. But I'd like to know if anybody's come across such a thing off the shelf, and has a name to search for.

Cheers,

Pete

These might do you Pete but have to get the searchers out to find who is stocking them. I have got some from Holland for the rigs and may have found
some in Halfords or elswhere as have on the boat. Mind you these could be here from HK within a week.


http://www.ebay.com/itm/Auto-2-Pcs-...amp-Clips-Angle-Brass-Connector-/260984323701

 

[prv]

http://www.ebay.com/itm/Auto-2-Pcs-...amp-Clips-Angle-Brass-Connector-/260984323701

Thanks - but these are designed to go onto battery posts. They'd fit nicely onto 18mm diameter cable, which I calculate as being 250mm^2 - bit big for yacht batteries . Obviously they could be bent inwards a bit to go onto smaller cable, but probably not down to whatever mine is (don't actually know).

Pete

 

[pvb]

I've never seen anything which matches your description. The easy solution, as you've suggested, is to use an insulated post and put lugs on the ends of the cables.

 

[prv]

The easy solution, as you've suggested, is to use an insulated post and put lugs on the ends of the cables.

The reason I was reluctant to do that is that I have swallowed Gibbo's advice (of Smartgauge fame) about minimising connections in a charging circuit for best efficiency. Even a new, good connection will drop a fraction of a volt, and with the difference between charging voltages measured in tenths, it doesn't take many to start seeing a difference. However, since starting this thread I have realised that the cables I need to tap into are starter, not charging, cables so the point is moot

Pete

 

[pvb]

The reason I was reluctant to do that is that I have swallowed Gibbo's advice (of Smartgauge fame) about minimising connections in a charging circuit for best efficiency. Even a new, good connection will drop a fraction of a volt, and with the difference between charging voltages measured in tenths, it doesn't take many to start seeing a difference. However, since starting this thread I have realised that the cables I need to tap into are starter, not charging, cables so the point is moot

A properly made connection on a substantial post will have minimal resistance.

 

[Plevier]

Try looking for "line taps". Used to be commonly used on overhead cables, don't know if they still are.
Not usually a split clamp but a threaded body with a slot down it and a clamp nut.
Ah, here are some. http://www.tlc-direct.co.uk/Main_Index/Necessities_Index/Line_Taps/

Here's the more traditional type I was thinking of, but these are from India. http://www.meetindustries.co.in/Splitbolts_Splitbolt_Connectors_Linetap.htm

 

[prv]

A properly made connection on a substantial post will have minimal resistance.

Well, it's not my theory, so I'll link you to Gibbo on the matter: http://www.smartgauge.co.uk/alt_how.html

Pete

 

[rob2]

It might help to specfy why you want to tap off the cables and what loadings and therefore sizes are involved. E.g. if you are taking a low load feed from the cables or just sensing wires, then there may be an IDC connector which would suit (similar to Scotchlocks).

Rob.

 

[PCUK]

You can get crimps that take up to 70mm or more. These can be crimped in the vice if necessary. Index Marine for one, sell them.

 

[nigelmercier]

You can get crimps that take up to 70mm or more. These can be crimped in the vice if necessary...

... with a suitable die of course.

 

[PCUK]

Not necessarily.

 

[nigelmercier]

You can get crimps that take up to 70mm or more. These can be crimped in the vice if necessary...

... with a suitable die of course.

Not necessarily.

Oh dear. Unless a crimp is designed to be crimped between two parallel surfaces, doing so will not result in a good join.

 

[maxi77]

Oh dear. Unless a crimp is designed to be crimped between two parallel surfaces, doing so will not result in a good join.

+1

Having done both there is no comparison and soldering would be better

 

[prv]

... with a suitable die of course.

I have a hydraulic crimping machine with accompanying dies - but I suspect PCUK misread the question as I can't imagine any normal crimp being fitted to the middle of the cable. In any case, as I've already said, the whole requirement was based on a faulty assumption - I want to leave the charging cables unbroken, and it's the starting cables that I need to attach to.

Pete

 

[BERT T]

CABLE LUG



This is available here: http://www.steeplejack.co.uk/Store/p-Earth_rod_to_cable_lug_clamp_(type_B)-44.aspx

 

[prv]

View attachment 31080View attachment 31080

That looks like exactly what I was asking for - thanks.

Pete

 

[Plevier]

View attachment 31080View attachment 31080

This is available here: http://www.steeplejack.co.uk/Store/p-Earth_rod_to_cable_lug_clamp_(type_B)-44.aspx

That's meant for solid rod not cable.

 

[pvb]

Well, it's not my theory, so I'll link you to Gibbo on the matter: http://www.smartgauge.co.uk/alt_how.html

Ah, right! I reckon that Gibbo must be related to Mr Sterling, as they both have a habit of writing reams of stuff. Lots of people assume (with both of them) that they must know what they're talking about, because they write in such lengthy detail. The specific article you linked to probably isn't strictly relevant to many boatowners, as most people these days seem to have battery-sensed alternators (either directly or via "smart" regulators). However, Gibbo says that a typical connection has a resistance of 200 micro-ohms (0.0002 ohms). I think that's an exaggeration - commercial crimp connections should typically have a resistance of only 25-30 micro-ohms. So, straight away, there's a question mark over the calculations in the article. And, as I posted earlier, properly made connections on a substantial post will have minimal resistance.

 

[prv]

The specific article you linked to probably isn't strictly relevant to many boatowners, as most people these days seem to have battery-sensed alternators (either directly or via "smart" regulators).

Really?

I don't know about the prevalence of external regulators, but I thought battery-sensed alternators were relatively rare.

Pete