Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
Solder versus Crimp
#31
(05-15-2018, 07:01 PM)completelycharged Wrote:
Lugs will only heat up at one point and that is the junction between the circular and flat section as this can be the thinest cross section for current to flow, which is more visible in the incorrect desing for high amps image....

Crimp twice.. no flared ends.

You can also get heating if there's poor contact somewhere, eg bolt or crimp is loose, etc?

There's special crimps made with flared ends for use with multi-strand wire, to help get the stands in vs the regular types, used some here :-)
But yeah you don't want your crimps gaping after crimping!
Running off solar, DIY & electronics fan :-)
Reply
#32
Ordered my hydraulic crimper and received the 70mm2 crimping lugs in the mail. All I need now is some cable and the practice crimping will begin. The advice in here has been great, so now it's down to the idiot (me) on the end of the crimper. May also grab some copper pipe and have a go at making my own lugs.
Korishan likes this post
<<< Contact me for quality used Yuasa LEV40 and LEV50 prismatic lithium batteries in Australia >>>
Reply
#33
Copper pipe is too thin unless you solder fill after crimping, even then it will still get hot unless formed properly.

Standard copper pipe is 0.7mm wall thickness for 15mm pipe and this is the equivalent of a 30mm2 conductor, which is less than half your cable thickness and your 70mm2 cable will fit inside the pipe, probably with the insulation on.

After crimping if you are "testing", cut the lug in half at the center of the crimp and check that the copper has been fused into a single block. Solder should not be able to pass the crimp point if enough pressure has been applied.
Korishan and Ibiza like this post
Reply
#34
Thanks for the advice re copper pipe. I had intended on making the connectors below for my charge controller, rather than using raw cables. I figured making the pin lugs from copper pipe and soldering should be ok.



EDIT: I failed to mention, the cable I will be using is 35mm2 for the connection between the charge controller and battery busbar.
<<< Contact me for quality used Yuasa LEV40 and LEV50 prismatic lithium batteries in Australia >>>
Reply
#35
Use bootlace ferrules where the cables need to go into the charge controller...

(05-16-2018, 10:26 PM)gregoinc Wrote: Ordered my hydraulic crimper and received the 70mm2 crimping lugs in the mail. All I need now is some cable and the practice crimping will begin. The advice in here has been great, so now it's down to the idiot (me) on the end of the crimper. May also grab some copper pipe and have a go at making my own lugs.

Personally I wouldn't mess about making copper tube terminals (lugs)... they are so cheap, just buy them. I think I paid £1 each for 70/8's last week, delivered next day. eBay/Amazon...
Current system: 9.6kWh wet Nicad batteries, 16S1P Calb LiFePo4 210aH, Batrium WM4, Outback vfx3048 inverter, mx60 mppt controller, flexware 500 mounting hardware, 2.4kW solar array, 6kW lister diesel genset. MY'13 Vauxhall Ampera
Reply
#36
For 75mm2 cable use 1/2" OD copper pipe if you have any around as the stripped cable should just fit inside and then crimp the pipe like a bootlace ferrule, but remember that this will make the csa of the cable over 75mm2.

One of the other methods that was used in the past is to bind the cable with a smaller diameter wire.

Could not find an image, but it is along these lines where the trands are over bound by a slightly thicker single strand. Basically for the over bound strand to take the terminal pressure away from cutting into the thiner single strands of the cable.

Another option, just solder it...
Rad and gregoinc like this post
Reply
#37
(05-18-2018, 11:20 AM)HughF Wrote: Personally I wouldn't mess about making copper tube terminals (lugs)... they are so cheap, just buy them.

One of the joys with living in the land downunder (Australia)... 9 times out of 10 an Amazon product doesn't ship here... or if it does, the shipping is the cost of a Lamborghini Tongue

So I get your point... and we can order from China, just not always that cheaply Smile
<<< Contact me for quality used Yuasa LEV40 and LEV50 prismatic lithium batteries in Australia >>>
Reply
#38
I read somewhere (manufacturers instructions I think, can't find it now) not to use wire with only a few stands (eg 7) into screw clamp type high current terminals (not bolt type).
Theory explained was this created a smaller contact area & therefore hot spots.
This would apply to some of the methods described above.

Crimping a wire in a lug & bolting to a bus bar, etc is different.
Running off solar, DIY & electronics fan :-)
Reply
#39
The main issue with screw terminals and thin stranded wire is the pressure and twist from the screw will usually cut a few of the strands with medium pressure. The second issue is that the thin wire, if not twisted and doubled over, may not actuall be in contact with the terminal if it is a barrel because the screw may only end up putting pressure a few strands while the others are free.

With stranded wire, if the terminal is large enough always bare off twice the terminal length, twist it so that it is compact and not stranded and then double over. Ideally with thin wire double back and then solder if it is not just a single fix, i.e. it will be fixed and removed more than once.

That was the way I was tought from an electrical installation perspective.
Korishan likes this post
Reply
#40
(05-19-2018, 10:02 PM)completelycharged Wrote: The main issue with screw terminals and thin stranded wire is the pressure and twist from the screw will usually cut a few of the strands with medium pressure. The second issue is that the thin wire, if not twisted and doubled over, may not actuall be in contact with the terminal if it is a barrel because the screw may only end up putting pressure a few strands while the others are free.

With stranded wire, if the terminal is large enough always bare off twice the terminal length, twist it so that it is compact and not stranded and then double over. Ideally with thin wire double back and then solder if it is not just a single fix, i.e. it will be fixed and removed more than once.

That was the way I was tought from an electrical installation perspective.

The alternative to this, preferred in some countries, is to use ferrules. You crimp the ferrule around the strands and then you can insert the ferrule into the screw terminal.
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)