Lugs Electrical Contact Questions

[12VoltInstalls]

The connections on the actual batteries and inverter themselves will be correct (m8 lug on m8 battery terminal, m10 lug on m10 inverter terminal). Furthermore, my batteries are 2 x LifePo4 batteries in parallel

fine

This is what I have

namely, the angles of the 2 m10s to each other is of question

Other than my ocd not liking the 92.3* angle instead of a machinist’s true 90* ? LOL that’s fine.

No flanged nuts are being used. I'm using the standard design that victron recommends in their docs: nut->washer->nut->lug (or in my case, 2xm10 lugs)

Fine. Electrical flanged nuts have circumferential ridges that sortof act like a locking facility for the nut, but proper torque of the lower nut then ‘jammed’ by the top nut over a washer is just as effective or more so. I like a flanged / washer head nut at a minimum but prefer a washer between the terminal and the nut to not present rotational force on the terminal as well as present the clamping force over more surface area while not deforming the terminal in any fashion.

We just all hyper-OCD’d the thing but maybe someone learned important safety information.

 

[jt_retro]

Other than my ocd not liking the 92.3* angle instead of a machinist’s true 90* ? LOL that’s fine.

I'm very much on the same page as you here. I've spent more time than needed trying to get angles at 90 etc ?

So my cable delivery arrived from my supplier today. And I've got a suprise. I'm not sure what I was expecting a m8 lug on a 95mm2 cable to physically look like, but my they are massive. Is this normal (ie thicker cable, bigger surface of lug)? My only reason for concern, is that for my battery terminals and the Mega fuses (both m8 studs/holes), the terminal copper areas for both are smaller than the area of the m8 lugs! I think I'm still good here given that the entire battery/fuse terminals are covered?

Other suprise, the normal mega fuse holders I use don't accept a 95mm2 cable. Anybody know if mega (or someone else) make mega fuse holders big enough for such thick cables? For now, I've managed to connect the fuses and new cables "on top" of the fuse holder, rather than in them. Naturally, the lids won't go on.

Thanks

 

[12VoltInstalls]

they are massive. Is this normal (ie thicker cable, bigger surface of lug

Yes. And desirable.

 

[jt_retro]

Yes. And desirable.

Thanks, and I'm good regarding placing the lugs on smaller terminals? I can only assume that the smaller area of my battery terminals (and area of the fuse terminals) are rated for the respective device....

 

[12VoltInstalls]

and I'm good regarding placing the lugs on smaller terminals?

If the cable ring terminal end (lug) maximizes the contact area of the boss, stud base, or bolt terminal you are fine. It’s when the cable’s ring terminal is smaller and / or thin that is an issue.

 

[jt_retro]

If the cable ring terminal end (lug) maximizes the contact area of the boss, stud base, or bolt terminal you are fine. It’s when the cable’s ring terminal is smaller and / or thin that is an issue.

Thanks. Indeed, the cable lugs overhang!