galvanic corrosion resitance on battery, screw terminal vs soldered (EIG CELLS))

[jimmyhackers]

had one of my ebike batteries fell victim to galvanic corrosion....

half my own fault. bloody zinc screws instead of stainless ones.

just wondering wether soldered connections would be less corrosion creating than a soldered connection of two dissimilar metals?

essentially: my batts are probs gonna get wet again...am i better off soldering them all instead of screw teriinals?.

 

[liveforphysics]

You didn't mention the type of cells you're interconnecting.

If they are cylinder type cells, even stainless to Nickel generates a galvanic current in the presence of an electrolyte (like atmospheric humidity).

If you have a little smear of dielectric gel coating each contacting surface, it displaces the volume for humidity/condensate intrusion. No electrolyte/humidity/condensates, no galvanic effects occur.

 

[DogDipstick]

...erates a galvanic current in the presence of an electrolyte (like atmospheric humidity).

If you have a little smear of dielectric gel coating each contac.....

I absolutely prefers a conductive terminal coating like P8A Bundy Penetrox. As I just did with the power pos, neg, three phases on a 3 year tortured bicycle. R&R, no corrosion exhibited: and none foreseen on the new installation ( because i used the same stuff again)

I use the Dielectric only on the signal contacts, and the like. A headlight, a horn.... a hall sensor or encoder set: that might have positive and neg in the same connector, 5v+ and NEG. and or sensitive signal.

Enhance, dont degrade, the connection.

All power transmitting connection I use a conductive protection ( zinc bearing, usually, sometimes silver) against eh noble dissimilar reactions. This is all the phase lines, the power rails, and bus, fusing. Anywhere I do not want to increase resistance. Also, the Bundy Penetrox is much longer lasting and hardy than an Autozone bottle of Dielectric grease. Used in industry for manymanyyears, in every technicians bag certainly when there may be dissimilar metal reactions in the atmosphere.

Plus, it is "Made in the USA", (something that Permatex "Dielectric bulb grease" is not.

Whats dielectric anyway . Lol.

PENETROX™ A non-toxic 8 ounce squeeze bottle oxide inhibitor joint compound and lubricant.

A compound is an 8 oz. squeeze bottle of electrical joint compound for a proper electrical connection between metal parts such as conductors.
It is an oxide-inhibiting compound for preventing galvanic corrosion and enhancing the connection in electrical joints. It can be used in aluminum to aluminum, aluminum to copper, and aluminum to conduit applications.
It remains workable when stored in a dry environment under 100°F

https://cf-store.widencdn.net/graybar/b/0/3/b039fae6-242f-4385-a76b-7f9a453c6ef2.pdf?response-content-disposition=inline%3B%20filename%3D%2288047845-safety-data-sheet.pdf%22&response-content-type=application%2Fpdf&Expires=1646696329&Signature=P23ir3mB6wQ7NDSAswAnYU9DB-v5qnwbFFFmA3IZpS-SqBQ1f6kzMAQdF5KmQ2xsGPoOv1Vb3rFvLeKnaoFbTnSIhkPzfgusjdYdp19h46VNfA5nyjMJ4OXOCgthY-SICBt1QGnnPz7cYHPnbnmEicogoGn3XAWi7UVldFkQP7pFBZdwevBI53IQa446o70hUSkgmVc5ljoJoFfpkczX9oynbGnimnfpKl9Af2qdsN2Fn40GWkTse3JbhHD3H~OiqGF-MAcEAdITRL7xqgRWils1QKgSOfWUNRG9zDHdOU~WUjNzBatngeixt4MBmV8SJBZZPNkoutGAu1KyGDZ~jg__&Key-Pair-Id=APKAJD5XONOBVWWOA65A


https://www.graybar.com/penetrox8482-a-oxide-inhibitor-8-oz-/p/88047845

https://www.hubbell.com/burndy/en/Products/Power-Utilities/Inhibitors-Contact-Aids-Sealants-Paint/Oxide-Inhibitor/P8A/p/1907260

https://www.amazon.com/Burndy-P8A-Oxide-Inhibiting-Compounds-Container/dp/B008KLX2RY/ref=asc_df_B008KLX2RY/?tag=hyprod-20&linkCode=df0&hvadid=312431262871&hvpos=&hvnetw=g&hvrand=792433710538399879&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007417&hvtargid=pla-523949110761&psc=1

 

[liveforphysics]

You would use gels rather than greases to displace humidity if you ran long term tests my friend. Greases only last a few years because they are an oil thickened by a soap, the oil can and is absorbed out of the grease leaving the soap solids to crumble apart, and subjecting the materials around it to various species of oil absorption. The dielectric gels I use are single monomer chain components with nothing to seperate apart so they last for decades and never wick apart and crumble.

Dielectric means it doesn't conduct electricity. In a comprehensive study I did on different dielectric greases, with and without silver or copper conductive particles, including making my own SWCNT additive gels and greases. All conductive particle filled greases I tested in bolted clamp joints performed worse than the unfilled (no solids) greases and gels. My guess is that its just lengthening the conduction path and adding series current path interfaces.

Dielectric means something that doesn't conduct electricity. Fortunately, it's job is there to replace the voids that would have otherwise been filled with air, which is also a dielectric, but one that passes humidity and wicks condensates (unlike a gel or grease).

 

[999zip999]

How about ideal noalox for copper and aluminum connections ? I'm asking because this is a gray area in my brain. It's conductive ?

 

[jimmyhackers]

i asked about termination.....screwing or soldering.....not covering them with insulating grease/gel or waterproofing.

so.....again.....which is less likely to corrode, a screwed terminal or a a soldered terminal?

tbh i think i know the answer... its soldered. As theres zero "gap" between surfaces where corrosion can form. will be less dissimilar metals aswell,

p.s. they are eig 20ah cells. copper bus bars, terminals look "brassy". the internal square nuts in the cells seem to be stainless but still corroded badly.

 

[jimmyhackers]

well..... ive converted/soldered one battery.

amazingly average cell resistance has gone from 3-4mohms per cell down to 2 mohms. this is better than these batteries have ever shown with screw terminals. And suprisingly better than their manufacturers rating.

annoyingly this means i have to do it to the other batteries,

took me about 2 hours to convert one.....only another 2 more to do. :S

 

[liveforphysics]

well..... ive converted/soldered one battery.

amazingly average cell resistance has gone from 3-4mohms per cell down to 2 mohms. this is better than these batteries have ever shown with screw terminals. And suprisingly better than their manufacturers rating.

annoyingly this means i have to do it to the other batteries,

took me about 2 hours to convert one.....only another 2 more to do. :S

Considering the lowest impedance 18650s ever to enter volume manufacturing on our planet measure 4.5mOhm, and are only used for Formula 1 cars at a cost of >$100/cell, something tells me your numbers can only be confusion on how to measure impedance or bullshit.

 

[nicobie]

I've always used grease on my car and truck batteries and have noticed it turns into a kind of crud after awhile. Any suggestions/recommendations for a brand of gel to use in its place?

 

[DogDipstick]

i asked about termination.....screwing or soldering.....not covering them with insulating grease/gel or waterproofing.

so.....again.....which is less likely to corrode, a screwed terminal or a a soldered terminal?

tbh i think i know the answer... its soldered. As theres zero "gap" between surfaces where corrosion can form. will be less dissimilar metals aswell,

p.s. they are eig 20ah cells. copper bus bars, terminals look "brassy". the internal square nuts in the cells seem to be stainless but still corroded badly.

A ( tin, or silver) plated terminal will not corrode.

A bare copper terminal will. A bare aluminum terminal will.

A soldered terminal will corrode, given the composition of the solder, and or the flux used ( especially with some fluxxes)

.


I recently replaced a phase line to the winding on a motor. I crimped, then soldered, the connection, with a copper tin plated barrel then soldered Kester 60% lead into the joint.

....it burned the next day. However, given constraint, this is what I would do for a junction where I would want the least resistance. This was permanent install inside a motor case, where extreme vibration was encountered, along with the high currents. hard to get to, reliability required. No maintenance, considerations.

Cleaned with Alcohol or acetone.

A proper screw terminal takes into consideration the application environment. Will last longer, and be better. An enginoored terminal takes into account the ability to maintain, replace, takes the workers time into account, and also provides for a long lasting easily replaceable connection.

It will keep the tarnish away. I Fking promise you. I usually coat right after the phosphorous bath.

I use silver plated Panduit. All copper is plated with tin or nickel.

Usually tin, at its 19$ per poound.

...P8A Bundy Penetrox....Also, the Bundy Penetrox is much longer lasting and hardy than an Autozone bottle of Dielectric grease. .

Plus, it is "Made in the USA", (something that Permatex "Dielectric bulb grease" is not.

.

PENETROX™ A non-toxic 8 ounce squeeze bottle oxide inhibitor joint compound and lubricant.

A compound is an 8 oz. squeeze bottle of electrical joint compound for a proper electrical connection between metal parts such as conductors.
It is an oxide-inhibiting compound for preventing galvanic corrosion and enhancing the connection in electrical joints. It can be used in aluminum to aluminum, aluminum to copper, and aluminum to conduit applications.
It remains workable when stored in a dry environment under 100°F

https://cf-store.widencdn.net/graybar/b/0/3/b039fae6-242f-4385-a76b-7f9a453c6ef2.pdf?response-content-disposition=inline%3B%20filename%3D%2288047845-safety-data-sheet.pdf%22&response-content-type=application%2Fpdf&Expires=1646696329&Signature=P23ir3mB6wQ7NDSAswAnYU9DB-v5qnwbFFFmA3IZpS-SqBQ1f6kzMAQdF5KmQ2xsGPoOv1Vb3rFvLeKnaoFbTnSIhkPzfgusjdYdp19h46VNfA5nyjMJ4OXOCgthY-SICBt1QGnnPz7cYHPnbnmEicogoGn3XAWi7UVldFkQP7pFBZdwevBI53IQa446o70hUSkgmVc5ljoJoFfpkczX9oynbGnimnfpKl9Af2qdsN2Fn40GWkTse3JbhHD3H~OiqGF-MAcEAdITRL7xqgRWils1QKgSOfWUNRG9zDHdOU~WUjNzBatngeixt4MBmV8SJBZZPNkoutGAu1KyGDZ~jg__&Key-Pair-Id=APKAJD5XONOBVWWOA65A


https://www.graybar.com/penetrox8482-a-oxide-inhibitor-8-oz-/p/88047845

https://www.hubbell.com/burndy/en/Products/Power-Utilities/Inhibitors-Contact-Aids-Sealants-Paint/Oxide-Inhibitor/P8A/p/1907260

https://www.amazon.com/Burndy-P8A-Oxide-Inhibiting-Compounds-Container/dp/B008KLX2RY/ref=asc_df_B008KLX2RY/?tag=hyprod-20&linkCode=df0&hvadid=312431262871&hvpos=&hvnetw=g&hvrand=792433710538399879&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9007417&hvtargid=pla-523949110761&psc=1

Dammninit.

I've always used grease on my car and truck batteries and have noticed it turns into a kind of crud after awhile. Any suggestions/recommendations for a brand of gel to use in its place?

Penetrox is available as a grease, or a gel. Petroleum base, or not.

You choose your battle.


PENETROX
TECHNICAL INFORMATION
PENETROX A
PENETROX A consists of a natural (petro-
leum) base vehicle in which zinc particles are
suspended. For aluminum to aluminum,
aluminum to copper applications and
aluminum conduit threads. It is not recom-
mended for use with rubber and polyethylene
insulated conductors. UL listed to 600 volts.

PENETROX A-13
PENETROX A-13 consists of a non-
petroleum base vehicle in which zinc parti-
cles are suspended. Recommended for
aluminum to aluminum, aluminum to copper
applications and aluminum conduit threads.
Compatible with insulating materials such as
rubber, or polyethylene. UL listed and recom-
mended for all voltages.

PENETROX E
PENETROX E consists of a non-petroleum
base vehicle in which copper granules are
suspended. Recommended for copper to
copper applications, grounding and for use
on copper conduit threads. UL listed.


Easy to apply:
1. Scratch brush the conductor surfaces until
bright and clean.
2. Immediately apply PENETROX™ to the
conductive surfaces.
3. For EXTREME HIGH VOLTAGE applications, remove all excess
PENETROX™ after installation is com-
plete.


SHELF LIFE
When stored in its original container in cool
(under 100° F) dry environment, PENE-
TROX™ oxide inhibiting compound will
remain workable and functional for (5) years
from the date marked on the container pro-
vided it is mixed per instructions prior to use

 

[jimmyhackers]

Considering the lowest impedance 18650s ever to enter volume manufacturing on our planet measure 4.5mOhm, and are only used for Formula 1 cars at a cost of >$100/cell, something tells me your numbers can only be confusion on how to measure impedance or bullshit.

im using eig c020b 20ah pouch cells, here is their data sheet. i gave up on 18650s for ebikes a while ago.
http://liionbms.com/pdf/eig/ePLBC.pdf
spec says <3mohm

i use either my turnigy accucel chargers resistance test function (tolerance is 1mohm) or my isdts t6 chargers resistance test function (tolerance is 1.11mohm).
seeing as both give me similar and repeatable numbers i consider them reasonably accurate (enough for my needs).

but again....ive dropped about 1-2mohms per cell going from screwed in bus bars to soldered connections.
on my 18s battery..thats a fair old drop in overall resistance.

 

[DogDipstick]

seeing as both give me similar and repeatable numbers i consider them reasonably accurate (enough for my needs).

but again....ive dropped about 1-2mohms per cell going from screwed in bus bars to soldered connections.
on my 18s battery..thats a fair old drop in overall resistance.

I would love to see picture of this soldered terminal. Good for you. Be careful, like I said above, the joint must be cleaned. It can be hard as hell to solder pouch tabs to one another ( that is what I envision you are accomplishing, am I wrong? You are soldering tabs together? )

I trust the reading for the IR. Repeatable. Those machines. However, its getting to the nitty gritty of the machines capability. My machines can certainly tell me if the reading is 1/2 an milli-ohm or less. Repeatable and accurate. Very useful. Interesting.

You see how close the two are together: Lead (or Tin), and Copper. You see which one is the " less noble".




I have kept keen eye on your installation since this post: It has been two years.
https://endless-sphere.com/forums/viewtopic.php?f=14&t=109341

Dielectric means it doesn't conduct electricity. In a comprehensive study I did on different dielectric greases, with and without silver or copper conductive particles, including making my own SWCNT additive gels and greases. All conductive particle filled greases I tested in bolted clamp joints performed worse than the unfilled (no solids) greases and gels. My guess is that its just lengthening the conduction path and adding series current path interfaces.

Coincidentally, my definition of " Dielectric " differs from the " Definition " you just gave us. Which should I trust? Eh?

Lol. The repercussions of ones understanding may be... Grave. Given the circumstance.

di·e·lec·tric
/ˌdīəˈlektrik/
Learn to pronounce
Physics
adjective
adjective: dielectric

having the property of transmitting electric force without conduction; insulating.

noun
noun: dielectric; plural noun: dielectrics

a medium or substance that transmits electric force without conduction; an insulator.

I know what dielectric means, Sir. By definition. However, isolation is a world unto itself. Even high current or high voltage medical grade isolation transformers might not be anything special.. and leak like hell. Given.. variable.

Perhaps my definition IS wrong, in my own confusion: As to the composition of a grease, lipid, suspension, conglomerate, mixture, solution, slurry, solvent, or other medium.... the "gel" you refer to. I mean, I have certainly had my own fun with Colloidal Polymers. FoSho'.

Well.. Let's see this study.

Since you are " guessing here". Lets get some concrete research results on the table. Since you have them. Comprehensive studies are great.

....something tells me your numbers can only be confusion on how to measure impedance or bullshit. Hey I may be wrong.

My guess is that its just lengthening the conduction path and adding series current path interfaces.

Perhaps I could read this study and learn where I am wrong, or what am not understanding. Publish it here, for us simple minded folk. Please. I implore. I do not have any sort of formal education, as you might know. Your experience and formal education is very valuable. For the reader. Perhaps.

....of course it ( dielectric grease) is lengthening the conduction paths.. and yes, when you bolt ( smash) bare terminals together, the joint is very tight.. And will EXHIBIT better conduction. ...and very little space in between he conductors. I mean, you can slam two pieces of metal together hard enough they become one. However, terminal engineering in general is a set of tradeoffs based upon application... and.. if you dont want your copper to tarnish, it must be coated with SOMETHING.

Dontcha SAY?

However, if you have a bare copper terminal int he atmospheres, you need a protection from the galvanic reactions.

If you MUST coat, you would rather have a conductive terminal coating rather a non conductive, dielectric int he current path, NO?

All I know is that Pentrox is advertised as a "Conductive oxide inhibitor". It is NOT a dielectric grease.

All PENETROX™ compounds
contain homogeneously suspended metal particles. The suspended metal
particles assist in penetrating thin oxide film, act as electrical “bridges”
between conductor strands, aid in gripping the conductor, improve electrical
conductivity and enhance the integrity of the connection.

Aside: I cannot imagine how a powerful battery is built, rationally and within the constraint, with 4.5mOh cell. I never built with anything over 1.5mOh. Lol. Must have alot ( of cells ) in parallel to get any significant current, or... mebbe mebbe perhaps perhaps I am not understanding some things.

Jah Ras Tafari.



https://en.wikipedia.org/wiki/Dielectric
In electromagnetism, a dielectric (or dielectric material or dielectric medium) is an electrical insulator that can be polarised by an applied electric field. When a dielectric material is placed in an electric field, electric charges do not flow through the material as they do in an electrical conductor, because they have no loosely bound, or free, electrons that may drift through the material, but instead they shift, only slightly, from their average equilibrium positions, causing dielectric polarisation. Because of dielectric polarisation, positive charges are displaced in the direction of the field and negative charges shift in the direction opposite to the field (for example, if the field is moving parallel to the positive x axis, the negative charges will shift in the negative x direction). This creates an internal electric field that reduces the overall field within the dielectric itself. If a dielectric is composed of weakly bonded molecules, those molecules not only become polarised, but also reorient so that their symmetry axes align to the field.

 

[DogDipstick]

You would use gels rather than greases to displace humidity if you ran long term tests my friend. Greases only last a few years because they are an oil thickened by a soap, the oil can and is absorbed out of the grease leaving the soap solids to crumble apart, and subjecting the materials around it to various species of oil absorption. The dielectric gels I use are single monomer chain components with nothing to seperate apart so they last for decades and never wick apart and crumble.

Dielectric means it doesn't conduct electricity. In a comprehensive study I did on different dielectric greases, with and without silver or copper conductive particles, including making my own SWCNT additive gels and greases. All conductive particle filled greases I tested in bolted clamp joints performed worse than the unfilled (no solids) greases and gels.

How can a compound be a " dielectric grease" with "suspended silver particles", and still be "dielectric" ( as you claim the in the research of your study)?

I think this is where my confusion stems.

If you add " conductive " element to the dielectric compound,... it is no longer a " Dielectric " ?

Yes? No?

Perhaps this is where my confusion stems.

 

[DogDipstick]

How about ideal noalox for copper and aluminum connections ? I'm asking because this is a gray area in my brain. It's conductive ?

I dont know. I have gone and confused myself back into a circle again. Too. Lol. Is it a dielectric grease? or is it conductive? How can it be one.. but not the other.. and if.. but.. Oh nevermind.

 

[jimmyhackers]

ive finished..
here is what they were before...
a pic of what my 100w soldering iron does while slowly dying.
and pics of the pile of rubbish/weight ive removed, bolts, nuts, bus bars and casings, its about 1kg in total.
they are ever so slightly thinner now aswell.

all in all im pretty happy.

 

[amberwolf]

Lemme know if you decide you don't want to keep those "extra parts" you now have. I could use them with the cells I've got.

 

[999zip999]

Lifeforphysics had a big pack of those EIG cells 12 years ago. I think he knows a lot about those A.W. to.
Can someone tell me about the ideal noalox for copper and aluminum wire. And explain dielectric grease to me and its purpose. As I want to use it for a 14s battery build of spaim08 cell with Copper folded and copper rivets with .

 

[jimmyhackers]

been for 3 rides now... batteries have more punch and less sag.....

id say its pretty worth while doing this if have these cells and your looking for that little bit extra..