Use solder paste on terminals-busbar to improve conductivity?

BobR

Solar Enthusiast
First picture, first thing I notice is the tube of "Super Lube" which is a thermal transfer compound that is not conductive (hence it is called a dielectric).

Commonly used with an insulator for high power components to insulate them, yet thermally conduct to a metal heatsink.
Please do NOT use this on any connections. It belongs as a heatsink compound in your switching power supply, but not anywhere near your battery terminals.



Also, unless you are on a boat, keep seawater away from your connections, it will corrode anything.

This 10 year old article is interesting:


I'm not finding testing in a solution of 30% saltwater to realistic test conditions, unless you are on a boat with a leak.
Unless you are within sight of the ocean, shouldn't be any saltwater, even in humid air. Saltwater will corrode pretty much ANYTHING.

Interesting that the article you linked, and the article that is 10 years old (and linked in the one you posted) came to such different conclusions.


"Best Anti-corrosion Coating

Noalox (aluminum wiring corrosion preventative) and No-Ox-Id (terminal grease), out performed all others by a wide range."

vs

"However, it actually accelerated corrosion on the copper and solder test samples, which were significantly damaged."

Test procedure that says Noalox is bad:

"To find out, we modified a rock tumbler to provide a gentle washing. Testers filled the tumbler jar about two-thirds full with brackish water and mounted a bundle of standard metal samples (coupons) to one end. Aluminum, copper, and brass are galvanically coupled in one sample set, and cast iron and cold-rolled SAE 1020 steel are coupled in another sample set. The setup insulates the two coupon groups from each other, the tie bolt, and the brass legs.

Testers applied a uniform, thin coating of grease to each sample coupon and allowed the coupons to gently splash in the tumbler for 10 days; testers changed the water and cleaned the container daily to minimize grease re-deposition. We then observed and measured both corrosion and remaining grease coatings."

Test procedure that says Noalox is the best:

Unfortunately the testing used in the "best anti-corrosion coating" won't let me cut, it's a PDF.


I think the key difference is not being put in a rock tumbler.

View attachment 56425
"Dielectric means that it does not conduct electricity, so it would seem counterintuitive for use in an electrical connection. In fact, a dielectric grease is perfectly acceptable for most electrical connections. You want something that will seal out water and air, preventing both galvanic and general corrosion. In crimps, screw-on connections, and even most plug connections, the clamping force pushes the grease out of the way, settling in micro-crevices and around the outside of the connection where it displaces and keeps out air and moisture."
 

12VoltInstalls

Solar Addict
dielectric grease is perfectly acceptable for most electrical connections.
Agreed. However, in specs for maintenance in severe-duty things like bombardier groomers you have to check and refresh on a schedule- it’s not a once-and-done. Some auto parts store dielectrics turn white and dry out in 3-4 months in my experience.

I hate the stuff- it’s nasty and never goes away, hard to clean up, and my skin doesn’t like it: fluidfilm
It might not be made for dielectric applications but it sure does lock out oxygen and protects against water ingress.
I hate the stuff but it seems to last for several years where other stuff doesn’t.
 

Just John

Photon Sorcerer
"Dielectric means that it does not conduct electricity, so it would seem counterintuitive for use in an electrical connection. In fact, a dielectric grease is perfectly acceptable for most electrical connections. You want something that will seal out water and air, preventing both galvanic and general corrosion. In crimps, screw-on connections, and even most plug connections, the clamping force pushes the grease out of the way, settling in micro-crevices and around the outside of the connection where it displaces and keeps out air and moisture."
Instead of using something designed as a non-conductive thermal transfer compound, you could always use the "it's $4 and we designed it for this application" product. An electrician who uses white thermal compound won't pass inspection. Using something like noalox, they will.

Saying it is perfectly fine to use thermal compound is very bad advice.
 

fhorst

making mistakes so you don't have to...
Thermal compound won't work

Nickel plating probably gave you the first 45% improvement.

Noalox, ox-guard both accepted by the strickt rules for electricians, for DC and AC!

Unless you have more knowledge then the people who wrote the rules and accepted just a few products....

Best still available is laser welding.
After this:
Silver grease.
About $ 70 for a small tube, used for telecom battery installation.
Next, more affordable:
Noalox, Ox-guard

Be free to try anything, toothpaste works :)

If you want to make it really work..
Those 4 are your options.
Laser welding absolutely the best.
 

Just John

Photon Sorcerer
Thermal compound won't work

Nickel plating probably gave you the first 45% improvement.

Noalox, ox-guard both accepted by the strickt rules for electricians, for DC and AC!

Unless you have more knowledge then the people who wrote the rules and accepted just a few products....

Best still available is laser welding.
After this:
Silver grease.
About $ 70 for a small tube, used for telecom battery installation.
Next, more affordable:
Noalox, Ox-guard

Be free to try anything, toothpaste works :)

If you want to make it really work..
Those 4 are your options.
Laser welding absolutely the best.
Indeed, laser welding is by far the best option. It is what prismatic cells were designed for.
 

Luthj

Photon Sorcerer
Since carbon coated aluminum is part of the cell chemistry
The carbon isn't reacting with the aluminum though. In the airline industry we have a lot of carbon fiber in contact with aluminum. It really isn't an issue unless there are acids involved, or salt water. The MG stuff indicates it has corrosion inhibitors as well.
 

Sanwizard

Photon Sorcerer
So I did an experiment with my two 16s battery banks of 280ah cells. Both banks use 6mm tapped terminals with grub screws, and the same cheap busbars that come with the cells from China. Both banks are attached to identical JK 200amp/2 amp BMS's with the cheap sense wires that come with them.
First bank, I cleaned and polished each terminal, then used a tiny dab on no-ox-ID special just on the bus bar area that touches the terminal. The busbar went on first, then the sense wire, then a washer, and finally the nut. All tightened to 4nm.

The JK BMS measures between .2 and .4 ohms on the wires.
The second bank I used a liberal dab of MG Chemicals 8463 silver conductive grease on the threads of the grub screws that go into the terminals. Then on top of each cell terminal, I drew a circle using MG Chemicals 842AR-P silver conductive pen, and placed the busbar, then the sense wire, then a washer, and then the nut, tightened to 4nm.
The JK BMS on this bank shows every connection at .1xx ohm. Its been a few months now, and all my cells stay between .007V and. 008V Delta.
I would say that is a good test to show that the MG Chemical conductive products work better than no-ox-id special. I will be re-doing my first bank using the MG Chem method to see what happens.
 
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