[spdas]

I know I saw it somewhere, but took the easy way out and asked again here.

On the 8.8mm bolts on terminals of the TS cells, what torque do you use?

Also what covering, conductive paste do you use?
Do you coat the contact surfaces or just cover over the bolt from the outside?

Do you use any type of Locktite?

Any other preps or advice?

thanks
Francis

 

[GizmoEV]

I used NOALOX in the thread holes and post surface. I outlined what I did in preparing my batteries on my blog at http://2003gizmo.blogspot.com/2009/12/cleaning-battery-posts.html

For the next pack I do I want to get NO-OX-ID A-Special Electrical Grade because it doesn't have the zinc powder in it.

I don't know the torque I used. I went by feel but I don't know how to quantify it.

 

[dtbaker]

On the 8.8mm bolts on terminals of the TS cells, what torque do you use?

per thundersky:The suggested torque for the terminals with M8 bolts on 100AH cells is 20--22Nm.

I plan to:
- lightly sand terminal tops, and apply 'noalox'
- put a drop of loctite 'red' on M8 set screws in at 20Nm
- external tooth lock washers and
- drop of loctite 'blue' on nuts.

 

[cyclops2]

The 8.8 is a grade of bolt. The bolt size is a whole mm number except in the smallest sizes, normally.

Tightening torques for Aluminum & Copper nuts, which is what you are tightening in to, is a rare chart & requires some Machinist tables.

You know when you have just passed peak torque. It starts to get easier. A torque bar may help if it has a tension dial showing the change in tension. You would immediately relax all tension at the SLIGHTEST reduction of the needle or Digital Readout.

Another concern on flat tab types is the deformation of non-steel / iron metals. There are Dished Washers to help spread out over a larger area the bolt head pressures. They are placed between the bolt & the flatwasher. Several can be used to get sufficient compression pressures on large soft metal areas.

 

[GizmoEV]

I plan to:
- lightly sand terminal tops, and apply 'noalox'
- put a drop of loctite 'red' on M8 set screws in at 20Nm
- external took lock washers and
- drop of loctite blue on nuts.

You might want to consider a mill file for a smoother surface or a soft SS wire brush. Both worked fine for me except that the wire brush was a little faster. The file, however, pointed out a couple of posts where the aluminum nut which holds the post in place were not tightened down enough so the post wasn't sticking above the nut.

I have been using brass bolts & bronze lock washers and haven't had any back out. Are you sure you want loctite in an electrical connection with aluminum and copper? If you are that concerned about things loosening why not go with nordlock washers. They won't vibrate loose.

 

[dtbaker]

The file, however, pointed out a couple of posts where the aluminum nut which holds the post in place were not tightened down enough so the post wasn't sticking above the nut.

I think I do have a couple like that as well, file might be best.

I have been using brass bolts & bronze lock washers and haven't had any back out. Are you sure you want loctite in an electrical connection with aluminum and copper? If you are that concerned about things loosening why not go with nordlock washers. They won't vibrate loose.

nordlock washers are just too expensive... I am not worried about the locktite since I'd expect the current to flow basically only where the bus sureface touches the terminal top.... not followig the bolt which would have way less conductivity being Stainless.... I might skip the locktite on the nut and depend on the regular external tooh lock washers doing their job....