[Jeep Man]

So, any super nerds out there that can help - I'm using Amphenol's G2 series 300 connectors for my 2/0 cable.

All these high-end connectors require multiple tooling and time to assemble - man tear ($$$) are at the feet of stupid mistakes like forgetting to mount a ring before you did this-or-that and now it can't be undone or reversed or blah blah blah (<cursing and being forced to order a new $100++ connector).

So, the question I have is, would a pig-tail design reduce the resistant of the overall run - point A Connector to point B connector vs point A Connector to butt joint to point B connector.

I can build a G2 connector in a controlled environment (my dinning room) attached to say a 24" length of 2/0 cable then make my run in the vehicle, join the butt to butt end to the pig-tail and Bob's you Uncle.

The question is, how much do I loose in resistance with a butt joint?

Obviously, I would use an industrial, hex crimped, tinned, copper connector then a double wall, adhesive heat shrink over it for both strength and water proofing.

Thoughts?

- Patrick

 

[Jeep Man]

I'm thinking this for the butt coupler

or this one:

No solder, heavy crimp, strong heat shrink.

What do you guys think?

- Patrick

 

[kennybobby]

It looks like a good solution; probably couldn't measure any significant resistance increase unless the crimp wasn't done well.

What is the overall length of the 2/0 that would be used x (0.000080 Ohms per foot) --kinda hard to measure resistance that low.

In my book the Green One is the expert on crimping, Hammer Time ; couldn't find his dissection pictures but those are must see.

 

[Jeep Man]

It looks like a good solution; probably couldn't measure any significant resistance increase unless the crimp wasn't done well.

What is the overall length of the 2/0 that would be used x (0.000080 Ohms per foot) --kinda hard to measure resistance that low.

In my book the Green One is the expert on crimping, Hammer Time ; couldn't find his dissection pictures but those are must see.

The run from the back of the Jeep to the front will be about 8-10 feet.

Here's the specs for that one:

Brand	Thomas & Betts
Color code	Black
Conductor Size	2/0
Conductor Type	Copper
Length	2.13
Material	Copper
Outside Diameter	0.59
Specifications	Tin Plated Finish
Type	2-Way Long Barrel
Voltage Rating	600

Can you ping HammerTime, or attach the thread, that sounds interesting.

Thanks.

- Patrick

 

[Jeep Man]

It looks like a good solution; probably couldn't measure any significant resistance increase unless the crimp wasn't done well.

What is the overall length of the 2/0 that would be used x (0.000080 Ohms per foot) --kinda hard to measure resistance that low.

In my book the Green One is the expert on crimping, Hammer Time ; couldn't find his dissection pictures but those are must see.

....and just so I'm clear, you're saying that a proper butt joint, will be able to transmit the full electrical load as if it was not a cut / butt joint - right?

- Patrick

 

[kennybobby]

That is a link to one of his posts with a video, from there you can search all of his posts. run your mouse over it should be underlined, click it and go.

Orange is the standard color to identify HV cables on EVs.

The losses due to a good crimp will be very small and below your level to detect unless you have some expensive equipment.

What is the max or peak current that you expect or want to carry?

You may need some extra measures to increase the insulation of the crimped joint; tape and heat shrink wouldn't cut it. Look for the industrial solutions.

 

[Jeep Man]

That is a link to one of his posts with a video, from there you can search all of his posts. run your mouse over it should be underlined, click it and go.

Orange is the standard color to identify HV cables on EVs.

The losses due to a good crimp will be very small and below your level to detect unless you have some expensive equipment.

What is the max or peak current that you expect or want to carry?

You may need some extra measures to increase the insulation of the crimped joint; tape and heat shrink wouldn't cut it. Look for the industrial solutions.

That was super stupid of me - sorry for being so obtuse - THANK YOU for that link.

As for the butt joint - 600vdc is what we're rated at as is the wire. I'm using 2/0 shielded cable so my thought was to cut it back carefully, expose the shielding then the core cable, make my butt joint, add back the cleanly but outer jacket, run a jumper between shields, cover with first layer of single wall adhesive heat shrink then sleeve the whole thing with dual wall orange adhesive heat shrink.

Man, now that I'm done typing that, I might be over killing it....

Anyway, that's the plan Man.

- Patrick

 

[Jeep Man]

That is a link to one of his posts with a video, from there you can search all of his posts. run your mouse over it should be underlined, click it and go.

Orange is the standard color to identify HV cables on EVs.

The losses due to a good crimp will be very small and below your level to detect unless you have some expensive equipment.

What is the max or peak current that you expect or want to carry?

You may need some extra measures to increase the insulation of the crimped joint; tape and heat shrink wouldn't cut it. Look for the industrial solutions.

Just walked around his videos, very interesting. For a relatively new sector, after watching some of his stuff, it amazes me how far the DIY EV market and makers have come.

I have two hand hydraulic crimping tools - a 5 ton and a 12 ton. The later can crimp up to 600kcmil cable (a little over and 1" in dia.).

I'm a crimp master (or is it Master Crimper, I get so confused with formal titles....).

- Patrick
(he, him, Crimp Master)

 

[piotrsko]

There is always gonna be a loss in a splice or connection. It comes with the ability to make that connection. A good one doesn't make much loss, but if it is really that important then just do a solid run of wire instead.

 

[kennybobby]

You didn't mention it was shielded cable initially; i don't know why you omitted that detail.

If these are for your motor wiring (3-phase) then just use a solid run without a crimp; the break in the shield will negate using a shield.

If these are for the + and - of the HV run from the pack then crimp might be okay, but i don't understand about using a shield on a single wire in a pair.

 

[Jeep Man]

You didn't mention it was shielded cable initially; i don't know why you omitted that detail.

If these are for your motor wiring (3-phase) then just use a solid run without a crimp; the break in the shield will negate using a shield.

If these are for the + and - of the HV run from the pack then crimp might be okay, but i don't understand about using a shield on a single wire in a pair.

Sorry about that.

Couple things;

• The run is ONLY for the 2 cable pack (+) & (-) run from the back of the Jeep to the front - NOT the 3-phase, 3 cable run from inverter to motor. Trust me, there will be no joints in that short (24") run.
• I was under the impression that shielding was more for EMF reduction then anything else.
• I DIDN'T want to use shielded cable and had plenty of wonderful 2/0 from EV West BUT, the connectors from Amphenol G2 series are for shielded cable only - that might sound funny for some but the assembly of the connector to cable uses the shielding as part of the 'structure' of the connector.

There's a handful of reasons to go with Amphenol's G2 series connectors, we can discuss separately (another thread?) if you guys care.

My only concern was the overall potential loss of current incorporating a butt joint.

You guys figured out why I'm even asking about this 'pig tail' idea - right?

- Patrick

 

[Jeep Man]

There is always gonna be a loss in a splice or connection. It comes with the ability to make that connection. A good one doesn't make much loss, but if it is really that important then just do a solid run of wire instead.

Roger roger - I can do that, well, I have tools that if properly used, I can easily do that.

Thanks

 

[Jeep Man]

I should get the Thomas & Betts butt connectors by this weekend, I'll lay it out and post then.

- Patrick

 

[onegreenev]

It looks like a good solution; probably couldn't measure any significant resistance increase unless the crimp wasn't done well.

What is the overall length of the 2/0 that would be used x (0.000080 Ohms per foot) --kinda hard to measure resistance that low.

In my book the Green One is the expert on crimping, Hammer Time ; couldn't find his dissection pictures but those are must see.

I can get those images for you.

 

[onegreenev]

I can get those images for you.

The images are at the end of the video. But here is a screen shot. Hammer vs hydraulic crimp. I will have to say that those thick connectors are difficult to hammer crimp because you can tear them. If you look closely at the part I crimped with the hammer you will see a small hole appeared and that would allow moisture and water if not properly sealed. So to avoid that you need to be sure to lubricate the tip of the crimper before crimping and be sure you don't tear them. They are thick but you can see the results. Some have commented on the hydraulic crimp as being a poor example but it was what someone else had done and used on their conversion that I fixed.

 

[Jeep Man]

The images are at the end of the video. But here is a screen shot. Hammer vs hydraulic crimp. I will have to say that those thick connectors are difficult to hammer crimp because you can tear them. If you look closely at the part I crimped with the hammer you will see a small hole appeared and that would allow moisture and water if not properly sealed. So to avoid that you need to be sure to lubricate the tip of the crimper before crimping and be sure you don't tear them. They are thick but you can see the results. Some have commented on the hydraulic crimp as being a poor example but it was what someone else had done and used on their conversion that I fixed. View attachment 135394

Thanks for sharing that.

I can think of a handful of pros of hydraulic v hammer but the number one, all things being equal (horrible cliché), the control you need for aligning connector to cable you just can't come close with a blunt force blow.

My G2 connector have two separate crimp points per connector and require 1-2+/-cm accuracy of crimp to make the second crimp work AND that crimp has to be dead on for the proper sleeve / strength issues to be adhered to for the overall strength and connectivity of the connection.

Also, aren't you showing lead battery connections - is that a fair comparison to say and inline crimp or a tinned tight fit lug or ring?

 

[onegreenev]

Thanks for sharing that.

I can think of a handful of pros of hydraulic v hammer but the number one, all things being equal (horrible cliché), the control you need for aligning connector to cable you just can't come close with a blunt force blow.

My G2 connector have two separate crimp points per connector and require 1-2+/-cm accuracy of crimp to make the second crimp work AND that crimp has to be dead on for the proper sleeve / strength issues to be adhered to for the overall strength and connectivity of the connection.

Also, aren't you showing lead battery connections - is that a fair comparison to say and inline crimp or a tinned tight fit lug or ring?

Yes, I'd say a fair comparison. As each side of an inline splice connector is no different than the end of a lead acid connector for the battery. The style of inline splice is exactly like what I used so it is fair and if you are doing the crimping out of the vehicle you still have full control of position even with blunt force trauma to the connector. The hydraulic crimpers are not as easy as you may assume either. They are fiddly and unwieldy and the wire can come out if you let go before you have enough compression on your connector. A good solid blow will usually set the position and you will have a good solid connection. In the end it is your choice. Most think the blunt force is the lesser quality. I disagree. You can see the difference. If you need I can do another crimp with my hydraulic crimper with a splice like you have the cut it as well. I would sacrifice a connector for someone. Yes? No?

 

[piotrsko]

Please do a show and tell with the hydraulic. Post a picture comparing them so people can see the small differences

 

[DANTM]

Interesting discussion. Although is is intuitive to assume a lug connection you can swing across a pit of alligators on is better than one that is (just enough) electrical connection. My understanding is that stranded wire has higher ampacity than a solid copper crossection, which is what you are doing when you crimp the hell out of a stranded wire into a solid copper wad at both ends of a butted connection. So maybe the goal is to size your butt connector to allow for some interlacing of the strands inside the butt and then just crimp over the area of this interlacing. Also, to back up to ensure more "mental insurance" consider the need to be concerned at all about this issue and look up the time to heat up under actual intended load. Here is a website/calculator that will tell you how long it will take to max the insulation rating for your wire. If you are using 00 wire and it says 350A constant load capacity, then why does Tesla use this size wire and hook it up to a motor that can see 1300-1500A for short durations. Using the website below you can play with figures that you get from measuring the resistance of your butt connection vs a un-butted length of wire.

Short-Time Current Rating of Conductor - Time Calculation

Webpage calculator to calculate the Short-Time Current Rating of Conductor

www.nepsi.com

 

[onegreenev]

Please do a show and tell with the hydraulic. Post a picture comparing them so people can see the small differences

I would say so people can see the difference and leave out the small. You did see a difference and a pretty substantial one in my image. Mine hammer crimp is also not a solid block of metal either. If you look you can see the wires but more tightly bound to help with vibration issues. With the crimped one when I removed them from the vehicle there were about 5 of them that just fell apart with no real tugging so the crimp was quite poor. Interesting that a hydraulic crimp is so crappy. Not to say all hydraulic crimps are crappy. Just showing a comparison between two different ways. I'll do a video and revisit this. I won't bother doing another hammer as you can already see what it does. I will however use my hydraulic crimper and cut it for you to compare. Give me a few days and I'll post when it's ready to view.