Just bought raw Lifepo4 cells. Wondering What to Use for Terminal Studs.

Hi everyone, I recently purchased these cells for my first DIY Solar System. The cells do not come with terminal studs. Just a threaded hole. I'm trying to find a threaded rod or bolt to use as a stud but I'm not sure which material I need to use. Because It's pretty difficult to find threaded copper rods, I was wondering if can I just use stainless steel? I've seen other batteries that use lead, brass, aluminum, steel, or whatever. I just don't know how important it is. Any feedback would be great. Thank you!

Spoonathan said:

Hi everyone, I recently purchased these cells for my first DIY Solar System.

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Takes me to a login page.

Spoonathan said:

The cells do not come with terminal studs. Just a threaded hole. I'm trying to find a threaded rod or bolt to use as a stud but I'm not sure which material I need to use. Because It's pretty difficult to find threaded copper rods, I was wondering if can I just use stainless steel? I've seen other batteries that use lead, brass, aluminum, steel, or whatever. I just don't know how important it is. Any feedback would be great. Thank you!

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Stainless grub screws.

These worked great for my 280Ah Eve cells:

Stainless steel is probably the most commonly used material for both studs and bolts. Unfortunately, SS has relatively poor conductivity compared to copper. The Schneider Conext XW+ inverter I'm using had Brass Bolts that came with it from the factory. There is a recent thread on this forum regarding how to maximize lug contact with the battery terminal.
While threaded copper rod or copper bolts are hard to find, copper washers are not. If your system is going to be under constant high amperage load I would suggest using a copper washer on the bottom under the lug and go with a SS bolt.

99.99% of what matters is:
1) The contact surface between the terminal face and the bolted conductor (ring terminal)
2) the clamping force between the terminal face and the bolted conductor (ring terminal)

Brass vs. copper vs. stainless vs. aluminum vs. mild steel threads in this context is like picking fly turds out of pepper.

Whatever material is used be very careful of the torque applied to the fasteners. The aluminum threads can be pulled out rather easily. Most recommend 4nm maximum (35 in-lbs). I recommend closer to 3 nm or 25 in-lbs. Get a small torque wrench for this.

Most use stainless grub screws. I used mostly aluminum bolts for increased conductivity and similar material to the terminal. With a bolt it is more difficult to get the perfect length to grab every thread but not bottom out in the hole.

Aluminum rod

Aluminum bolts

Copper bolts $$$

You can use stainless set screws. As the above poster said the studs will be carrying almost none of the current the face to face contact of the lugs to the terminal faces will be doing all of the work. the studs just hold it together.

Determine what threading your battery has. Mine were metric M8 x 1.25 threading. If you want some brass all-thread to make your own studs, I have one for sale. If you want some 1.5 inch long all-brass studs, I will sell you them for $3.00 apiece plus shipping.

Brass is more conductive than steel. The type of threaded M8 brass I have is marketed as corrosion-resistant and electrically conductive. PM me if you want any.