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Using aluminum lugs on 280Ah terminals

I assume your 280A terminals, like on my 272A Lishen cells, are aluminum as well.

Assuming I can adequately clamp the cells and vibration isolate them (skoolie/bus conversion here), would something like aluminum busbars be ideal, or is that more trouble than it's worth and I'd be better off with tinned lugs + welding cable for inter-cell connections? Even in spite of the dissimilar metals and greater variation in resistance than with aluminum busbars? I do worry about vibration like @HRTKD does - rough roads/light offroad and all that, and would hate to have a terminal get ripped out .
 
this Aluminum-Lug with Aluminum or copper wire is another viable option for my use-case, I’ll price it out...
If you are going to use copper wire use some NoAlox or equivalent. I only use those for temporary connections. I prefer crimps. They are used all the time on main lugs with aluminum wire for service panels.
 
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If you are going to use copoer wire use some NoAlox or equivalent. I only use those for temporary connections. I prefer crimps. They are used all the time on main lugs with aluminum wire for service panels.
Thanks.

As I stated in an earlier post, I priced it out and tinned lugs + 2/0AWH Welder’s wire is cheaper, so I’m dropping this idea and going with that...
 
Thanks.

As I stated in an earlier post, I priced it out and tinned lugs + 2/0AWH Welder’s wire is cheaper, so I’m dropping this idea and going with that...
As I learn more about aluminum galling on aluminum as well as galvanic corrosion, I’m back to considering this idea.

A plated aluminum lug w/ setscrew can be secured with a long aluminum bold locked into the terminal with Loctite or JB Weld and with washer, lock washer and nut to apply torque from below the bolt head can be installed once and never unthreaded.

Nut can be loosened if needed to rotate position but disassembly is achieved through the setscrew, not the terminal threads.

A variant of this idea would be to use a pair of short cables with lugs for each connection. Each terminal has a lug permanently mounted (in a way it can still be rotated when needed, as noted) and assembly/disassembly is achieved by torquing two lugs together in the middle of the connection.

Of course, if corrosion on the surface of the aluminum terminal is going to be a concern, that will be a mess no matter what (disassembly of the lug from the terminal will be needed).
 
Everyone keeps worrying about expansion and the effects of loading the terminals. This is basically only a concern because of the expansion of the cells, correct? Yes buss bars heat up and that is a consideration.

Has anyone considered a "non-standard" configuration (Narrow sides facing instead of broad sides)? Personally, I am configuring them in this way, using machined (flat) aluminum bus bars and epoxied zinc coated studs. I am still clamping them in a fixture, mainly because its a mobile application, but it will have some of the cycle increasing effects too I think.
 
Everyone keeps worrying about expansion and the effects of loading the terminals. This is basically only a concern because of the expansion of the cells, correct? Yes buss bars heat up and that is a consideration.

Has anyone considered a "non-standard" configuration (Narrow sides facing instead of broad sides)? Personally, I am configuring them in this way, using machined (flat) aluminum bus bars and epoxied zinc coated studs. I am still clamping them in a fixture, mainly because its a mobile application, but it will have some of the cycle increasing effects too I think.

I have thought about that configuration. But I do not think that I have ever seen it. So that made me think that there was a reason that I Wasn't thinking of. Have you started yet? Have pictures?
 
I have thought about that configuration. But I do not think that I have ever seen it. So that made me think that there was a reason that I Wasn't thinking of. Have you started yet? Have pictures?
I suppose the main issue is the form factor; you've got a skinny, 4.5ft long, battery if it's 4s, 9 ft long if it's 8s. Doesn't fit as many applications, I imagine. Still seems like a great idea for those who could fit it.

This may also be worth considering:
VpQtZrV.png


I'm not sure if this would be worse for longevity of connections, but instead of stretching the bus bars, you would essentially be rotating them about their lug connections as the cells expanded and contracted. 272Ah cells should have about a a 145mm distance between connections, diagonally.
 
I suppose the main issue is the form factor; you've got a skinny, 4.5ft long, battery if it's 4s, 9 ft long if it's 8s. Doesn't fit as many applications, I imagine. Still seems like a great idea for those who could fit it.

This may also be worth considering:
VpQtZrV.png


I'm not sure if this would be worse for longevity of connections, but instead of stretching the bus bars, you would essentially be rotating them about their lug connections as the cells expanded and contracted. 272Ah cells should have about a a 145mm distance between connections, diagonally.
This is the configuration I am planning y to to use for 8S...
 
No, the diagonal busbar configuration composed of 2/0 welder’s wire on the standard 8S single-row cell positioning...
Ah, gotcha'. I'm still considering aluminum bus bars, but my current go-to plan is #2 welder's wire for each of two 4S packs with a 120A BMS per pack, and then 2/0 welder's wire at the parallel connection between them. I assume for my purposes the ampacity is sufficient? I should be able to pull 240A but I doubt I'd ever be pulling more than 210A.

The aluminum bus bars are simpler and cheaper, but I agree, welder's wire and mechanically crimped lugs seem the way to go for a number of reasons.
 
I have thought about that configuration. But I do not think that I have ever seen it. So that made me think that there was a reason that I Wasn't thinking of. Have you started yet? Have pictures?
No, Im still working through a few details in my head so not quite ready to put my money where my mouth is. Just charging the last 2 of 16 cells to test and this weekend will start building the fixture. Ill get some pictures up then.
 
If it was a solid wire, that would work OK. The verbiage in the HD page makes it sound like this is intended for AC, not DC, which would be a solid wire, not stranded.
Why would ac vs dc make a difference on wire design?
There is zero difference with stranded vs solid conductors ac vs dc unless you exceed 400Hz
 
Why would ac vs dc make a difference on wire design?
There is zero difference with stranded vs solid conductors ac vs dc unless you exceed 400Hz

I think he meant that it's solid core wire (or semi-rigid if it's a bigger size) meant to be put in house walls for 120 V for example (so AC), by opposition to fine stranded wire meant for battery cables for example (so DC).
 
I think he meant that it's solid core wire (or semi-rigid if it's a bigger size) meant to be put in house walls for 120 V for example (so AC), by opposition to fine stranded wire meant for battery cables for example (so DC).
But we understand there is NO current carrying solid wire used in 120v construction. You could not bend it, and the heating/cooling expansion/contraction breaks/cracks lugs, breakers, and terminals

The only solid wire in 120v construction is smaller 12/14g non-current carrying ground wires
 
In the USA the most (only?) used type of wire is romex which is like this: https://upload.wikimedia.org/wikipe...Romex_cable.agr.jpg/800px-Romex_cable.agr.jpg as you can see it's solid core cable.

I don't know where the transition from solid to semi-rigid typically is in the USA but here (France) it's between the 2.5 and 4 mm² (our standard and most used sizes are 1.5, 2.5, 4 and 6 mm²) so all our lighting (1.5 mm²) and socket (2.5 mm²) cables are solid core and the higher power stuff is semi rigid (typically 7 strands).
 
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But we understand there is NO current carrying solid wire used in 120v construction. You could not bend it, and the heating/cooling expansion/contraction breaks/cracks lugs, breakers, and terminals

The only solid wire in 120v construction is smaller 12/14g non-current carrying ground wires
Solid wire is generally small ga, (10 and under) but grounding conductors #6 and #4 are readily available, however, as you said, current carrying... #10 and smaller by code.
 
I think he meant that it's solid core wire (or semi-rigid if it's a bigger size) meant to be put in house walls for 120 V for example (so AC), by opposition to fine stranded wire meant for battery cables for example (so DC).
No, he is discussing DC use case, and he stated DC must use solid conductors, and that is certainly incorrect.
 
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