diy solar

diy solar

Correct Battery Torqueing???

Bobs RV 36'

Something Burning?
Joined
Mar 22, 2021
Messages
22
What is the correct torque on a 6-M and an 8M Stud?

My life as an electrical contractor tells me...

1) Over torqueing will strip the threads that could lead to an under torque situations

2) Under torqueing could cause funky random resistance, heat buildup and bad stuff happening!?

This would also apply to BMS, Shunts etc.

To me... This seems like a critical step in a safe battery build that is overlooked quite often, at least in the video's I've watched.

I haven't seen a thread on this yet. I would imagine the values would be in Inch Pounds or Newton Centimeters.

Thanks!
 
This topic has been covered ad nauseum, but you have to dig to find the thread. Here is a link to the thread:

 
on a recent video i have now seen stripping at 35 INCH lbs. :mad: I will start at 25 INCH LBS and end with 30" lbs and leave it that. ?✌️
 
on a recent video i have now seen stripping at 35 INCH lbs. :mad: I will start at 25 INCH LBS and end with 30" lbs and leave it that. ?✌️
Was a thread locker used on the studs? Can you post a link to the video?
 
Was a thread locker used on the studs? Can you post a link to the video?
yes thread lock was used in the vid. thread lock should never be used! I believe its the same video you're referring to.
 
While I don't endorse thread locker on terminals, if you're going to use it there, the torque value has to be decreased to take into account for the added "lubrication" that that the thread locker provides while tightening the fastener.
 
While I don't endorse thread locker on terminals, if you're going to use it there, the torque value has to be decreased to take into account for the added "lubrication" that that the thread locker provides while tightening the fastener.
It depends on whether one is using studs or screws. The thread locker is used on the studs (grub screws) and threads in the terminal. Once it cures there is a very strong bond between the studs threads and the terminals threads. This helps to prevent the stud from stripping out of the terminal. Using a thread locker allows for more torque to be applied....at least the 4nm torque that's now being recommended.

If cells come with screws instead of studs, then a permanent thread locker should not be used. The same applies if cells have laser welded studs on them.

The EVE cells we were getting last year did not have the option for laser welded studs. So someone came up with the idea to use studs instead of screws.

yes thread lock was used in the vid. thread lock should never be used! I believe its the same video you're referring to.
I would not go so far as to say thread locker's should never be used. If using studs it does help if applied properly and allowed to fully cure. Some of the loctite variations require a primer while others don't.

I haven't referred to any videos in this thread but I don't remember every thing I have posted in every thread. If you can refer me to the video I referred to I would appreciate it. Or post the link to the video here.
 
It depends on whether one is using studs or screws. The thread locker is used on the studs (grub screws) and threads in the terminal. Once it cures there is a very strong bond between the studs threads and the terminals threads. This helps to prevent the stud from stripping out of the terminal. Using a thread locker allows for more torque to be applied....at least the 4nm torque that's now being recommended.

That's a good point that I glossed over. However, I suspect that putting a stud into the terminal with thread locker on the threads may not be as effective as it could be. Without some pressure on the stud to make full contact with the terminal threads the thread locker may not be able to do it's job as well as expected. Just a thought.
 
That's a good point that I glossed over. However, I suspect that putting a stud into the terminal with thread locker on the threads may not be as effective as it could be. Without some pressure on the stud to make full contact with the terminal threads the thread locker may not be able to do it's job as well as expected. Just a thought.
That's a good point also and might explain why one of mine stripped out even though I used a thread locker. It could also be I over torqued. I now have a beam style torque wrench but I am looking at the one jwelter99 posted above. Some of my studs had a bit of play in them. I resorted to Standard JB Weld to repair the stripped terminal. So far it's holding with 3nm of torque. The other studs are ok. I am attaching a bad memory...lol The stud and the threads that came out.
 

Attachments

  • stud.jpg
    stud.jpg
    57.1 KB · Views: 14
Has anyone else actually looked at torque recommendations for an M6 and derated the values for the low tensile PSI rating of this soft aluminum?
Even 4 NM seems too tight to me.
 
I thought the consensus was that 8 NM torque was the maximum the case could handle.... not the threads.
So if you are re-tapping M8 threads do not apply more than 8 NM to the tap.

That's the general consensus. Why they don't also specify the torque for the terminal fasteners is up for debate.
dunno.gif
 
That's the general consensus. Why they don't also specify the torque for the terminal fasteners is up for debate.
dunno.gif
I think they don't specify that because they don't supply them with the threaded terminals .... just a smooth top terminal that can be laser welded or tapped .... I think they are being tapped for or by the aftermarket folks...... I could be wrong.
 
Remark: The pole is a double aluminum pole structure. The internal screw with size M6 is used in the poles. The anti-torsion of pole is 8Nm. The torsion should be less than 8Nm when used. The effective thread hole depth is 6mm.
The above is their exact text. I take it to mean the stud torque should be under 8Nm when the threaded hole is used.

M6 into aluminum is rated for about 8.8Nm as long as depth is at least 6mm. So that also agrees with the EVE spec.
 
The above is their exact text. I take it to mean the stud torque should be under 8Nm when the threaded hole is used.

M6 into aluminum is rated for about 8.8Nm as long as depth is at least 6mm. So that also agrees with the EVE spec.

The pole is the entire terminal. It's like an iceberg. There's more below the top of the cell that you can't see. Maybe it's a bad translation to English. Nobody that has any respect for their cell will tighten to 8 Nm.
 
It depends on whether one is using studs or screws. The thread locker is used on the studs (grub screws) and threads in the terminal. Once it cures there is a very strong bond between the studs threads and the terminals threads. This helps to prevent the stud from stripping out of the terminal. Using a thread locker allows for more torque to be applied....at least the 4nm torque that's now being recommended.

If cells come with screws instead of studs, then a permanent thread locker should not be used. The same applies if cells have laser welded studs on them.

The EVE cells we were getting last year did not have the option for laser welded studs. So someone came up with the idea to use studs instead of screws.


I would not go so far as to say thread locker's should never be used. If using studs it does help if applied properly and allowed to fully cure. Some of the loctite variations require a primer while others don't.

I haven't referred to any videos in this thread but I don't remember every thing I have posted in every thread. If you can refer me to the video I referred to I would appreciate it. Or post the link to the video here.
I will try to find the video again for you,
Guy in vid was torqueing at 35 in lb with a screwdriver looking torque wrench, if I remember correctly he previously used thread lock and probably didn't take into account the lube factor. probably originally over Tq that lead to a strip.

I have never used lock tight or equivalent on any of the residential 120/240 main panels I've installed, come to think of it, never on any electrical wiring, buses, relays etc.

I would imagine on these soft battery terminals that it might exceed the torque value removing them for a servicing and strip as well as over torqueing as a lubricant.

terminal spray I've used for corrosion resistance on homes by the ocean but that's post torque, wouldn't matter.
I'm still thinking 30 in lb should be a satisfactory clamping pressure to allow safe servicing and re-torqueing.

How do you feel about terminal spray post torque on these 280ah batts?
 
Back
Top