Tightening M6 screws

[Dave (Boog)]

Hi,
I'm new to building battery packs. I just bought 8 120 ah LIFEPO4 cells to construct a 24 volt battery. These cells have screw in M6 terminals. I've been reading as much as I can on the various forums and have recently seen posts talking about tightening screws, bolts and studs. Some of these posts talk about using a Torque wrench to tighten these screws, bolts and studs.
The M6 screws that came with my cells are made to be tightened with a simple hex key. If I tighten my M6 screws so they are snug is this enough? Do I have to go overboard and use a Torque wrench to some how tighten these to a certain nm value?
I don't want to mess up these cells, they cost me a lot of money. Any information is much appreciated.

 

[FilterGuy]

Dave: The stainless steel studs are considerably harder than the soft aluminum of the cell pads. Consequently, just threading the studs in and out a couple of times can damage the aluminum threads. Even brand new, the aluminum threads are easy to strip. When they are damaged it is VERY easy to strip the threads.

My recommendation is to put the studs in with red loctite (use primer) or JB Weld and never take them out again. Furthermore, you do not tighten them down... In fact I like to back them off from the bottom by 1/8 turn. Some people like to put a nut thumb tight on the stud so that the stud stays straight while the glue sets.

Once the cells are in place, use a torque wrench while tightening the nut onto your lugs. While you are tightening the nut, use an allen wrench to hold the stud so you don't accidentally break the glue.

We had a lengthy discussion about this just recently:

JB Weld versus Loctite for grubscrews

I’m getting ready to install 20mm SS M6 grubscrews into my EVE 280Ah cells and am down to the last detail of whether to use JB Weld or Loctite to secure the threads. So I’m asking those members who have experience with both whether there is any disadvantage to using JB Weld over Loctite that I...

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[JanLewisfD]

In such cases, I prefer to use a red Loctite, and the connection holds stronger. I even used it once to treat the protruding threaded part of the tek screws from Scrooz when assembling the terrace at the pond. I had an experience with JB Weld. I found it to be more brittle than the red Loctite. It is very good when the stud is screwed as tightly as possible into the aluminum so that the load is on the metal, not the glue. If the threads in the aluminum are a little loose, it is better to use a nut to keep the stud straight.