Improving Contact Area on Welded Stud Pads

[FoxMeister88]

Every 20 minute job is only one stripped or broken bolt away from a multi day ordeal through hell

Story of my life lol

 

[Brett V]

I don't mean to discourage anyone. The tapped holes and studs are both up to the task if treated properly. I'm the poster child for the old school of "Tighten it till it squeaks"... my dad used to get so mad at me when he had to beak lug nuts on a wheel I had put on at some point in the past. All we really need here is a sufficient contact surface area and a little snugness. A poor connection is rarely improved by making it a tighter poor connection.

 

[HRTKD]

I have the original EVE cells with tapped terminals. I've had no problems with using the provided screws in my eight cells. I would rather have good contact area and tapped terminals than reduced contact area and a stud. I can put whatever size bolt/screw I want into the tapped terminal, or even a grub screw. I have a good supply of different length aluminum bolts that I plan to use.

 

[Horsefly]

I provided a link above to what appears to be the correct one:

A quick search found these

10mmX18mmX2mm

Good find @Stepandwolf! Your search technique on Amazon must be better than mine.

For everyone looking at this thread: These are probably better, as they have an explicit 10mm inside diameter. I ordered some last night and they arrive today. I'll post the results here. (If they are way better, I'll edit my original post above too!).

 

[Bubba1]

Thanks for the link on the crush washer. One less thing to chase down.

 

[Short_Shot]

Any reason to not use copper crush washers?

Aluminum oxide is highly resistive compared to aluminum itself and I would think (could be wrong) that eliminating two layers of the stuff at this interface could only improve things.

Of course this can be reduced by sanding each surface before connecting it.

 

[Bubba1]

Found this....Aluminum will be very susceptible to galvanic corrosion in contact with copper, assuming that the two metals are also in contact with a common electrolyte (such as water with some ionic content.) My batteries are on a boat in humid climate.

 

[Short_Shot]

Found this....Aluminum will be very susceptible to galvanic corrosion in contact with copper, assuming that the two metals are also in contact with a common electrolyte (such as water with some ionic content.) My batteries are on a boat in humid climate.

Yeah but you can plate it though.

I guess you could plate the aluminum too but I don't know if the process of plating itself creates the oxide under the plating.

Of course diy plating isn't exactly a walk in the park.

 

[Bubba1]

Yeah but you can plate it though.

I guess you could plate the aluminum too but I don't know if the process of plating itself creates the oxide under the plating.

Of course diy plating isn't exactly a walk in the park.

Perhaps lead would be a better option

 

[Stepandwolf]

A stripped tapped hole is more recoverable than a bad experience with a stud. I can easily put a helical thread insert in a stripped hole or just drill it out to the next size and tap new threads. On the 230 amp EVE cells I got, the supplied buss bars are too thick to stack and have enough threads to work with. The studs are too short...I already stripped the top two threads off of one just using a nut driver. Once I have assembled all the cells in series, this will not be a problem but for top balancing, it's a little dicey.

I purchased studs before I even got my batteries as I knew I didn't want to use the supplied grub bolts. By the time you stack buss bars, BMS lead, and who knows what they are just too short. At least using studs I know I am using all the threads and just need to be careful I guess.

 

[Stepandwolf]

Good find @Stepandwolf! Your search technique on Amazon must be better than mine.

For everyone looking at this thread: These are probably better, as they have an explicit 10mm inside diameter. I ordered some last night and they arrive today. I'll post the results here. (If they are way better, I'll edit my original post above too!).

How do you get next-day service? I have watched Prime 2-day delivery slip to days and weeks. Seems AZ should no longer charge for Prime delivery since they no longer seem able to promptly ship like they used to. When asked, they blamed it on COVID but that excuse doesn't work for me any longer.

Hope they come in and work out for you. I don't have a studded version of the battery to test the diameter on.

 

[Short_Shot]

How do you get next-day service? I have watched Prime 2-day delivery slip to days and weeks. Seems AZ should no longer charge for Prime delivery since they no longer seem able to promptly ship like they used to. When asked, they blamed it on COVID but that excuse doesn't work for me any longer.

Hope they come in and work out for you. I don't have a studded version of the battery to test the diameter on.

Depends where you are.

I live less than a half hour from two distribution centers on opposite sides of me. Same or next day delivery is common for popular items.

I just ordered some TIG consumables for example that showed up next day, and not too long ago ordered some cat food that showed up 4 hours later same day.

 

[Stepandwolf]

Depends where you are.

I live less than a half hour from two distribution centers on opposite sides of me. Same or next day delivery is common for popular items.

I just ordered some TIG consumables for example that showed up next day, and not too long ago ordered some cat food that showed up 4 hours later same day.

I am currently living in New Mexico where Bezos came from, yet he has never put a distribution center here. My issue isn't as much the shipping, but the filling of the order. It routinely takes them3-4 days to fill an order. I am referring to fulfilled by AZ orders, not 3rd party.

Checking my recent orders.
Ordered 8/5, filled 8/9, arrived 8/11
Ordered 8/2, filled 8/5, arrived 8/9
Ordered 7/26, filled 7/29, arrived 8/3

I remember back in the say when placing an order, it would say something like, place order by 4pm, get 2-day delivery. I never see that anymore. If it takes them 3-4 days to even fill the order, they will never arrive in 2 days.

Used to be if a package didn't arrive in 2 days, you would call, complain, and they would add a month on your Prime. When their service deteriorated so bad, they no longer offer that.

(getting off of soapbox)

 

[Horsefly]

How do you get next-day service? I have watched Prime 2-day delivery slip to days and weeks. Seems AZ should no longer charge for Prime delivery since they no longer seem able to promptly ship like they used to. When asked, they blamed it on COVID but that excuse doesn't work for me any longer.

Hope they come in and work out for you. I don't have a studded version of the battery to test the diameter on.

I actually ordered them around 9:45pm (MDT) last night, and they were delivered at 11:45am this morning. So yeah, it's pretty incredible. I'm in the Denver metro area, and we have at least two fulfilment centers here. During the height of the pandemic Amazon (and everyone else) really got swamped and even a 2-day Prime delivery was not likely. Recently though, I get lots of things in one day. Two other items I ordered yesterday (but earlier) came at the same time as the washers.

The bad news: The washers don't fit. I got out my caliper (as I should have in the first place) and measured everything. What I was calling the 10mm pad is actually 11.0mm. The washers that @Stepandwolf found and I bought were listed as 10mm i.d., but they are actually 9.61mm inside diameter. So I'm back to recommending my original pick: https://www.amazon.com/gp/product/B07SR2BDCK

 

[Stepandwolf]

I actually ordered them around 9:45pm (MDT) last night, and they were delivered at 11:45am this morning. So yeah, it's pretty incredible. I'm in the Denver metro area, and we have at least two fulfilment centers here. During the height of the pandemic Amazon (and everyone else) really got swamped and even a 2-day Prime delivery was not likely. Recently though, I get lots of things in one day. Two other items I ordered yesterday (but earlier) came at the same time as the washers.

The bad news: The washers don't fit. I got out my caliper (as I should have in the first place) and measured everything. What I was calling the 10mm pad is actually 11.0mm. The washers that @Stepandwolf found and I bought were listed as 10mm i.d., but they are actually 9.61mm inside diameter. So I'm back to recommending my original pick: https://www.amazon.com/gp/product/B07SR2BDCK

Dang....wish their ad had been more accurate. After further digging, I can find a lot of 11mm ID SS washers or steel, but not aluminum. Since the goal is to increase conductivity, an SS or steel washer isn't going to do it.

Didn't you say those jewelry washers were too thin?

Wouldn't it be easier to drill out the 2mm thick washers vs. using a washer that is too thin?

(BTW, go Vikings - 1.5 hours to kickoff)

 

[Lt.Dan]

I made some washers for Michael to sell in his group buy with cells.

Lishen 270ah-272ah cell group buy.

I received my 8 271Ah cells few days ago (ordered last days of December, supposed to be CATL, but it does not say it anywhere) and was quite happy: they looked like new, undamaged, voltage ranging from 3.285 to 3.291V. However, when I started reviewing posts about top balancing and compressing...

diysolarforum.com

I laser cut them out of 1000 series Annealed Aluminum (absolutely dead soft, very conductive). They made a perfect fit and increased surface area to 3/4". But everybody thought it wasn't that great of an idea, and not too many were sold.

 

[Short_Shot]

Dang....wish their ad had been more accurate. After further digging, I can find a lot of 11mm ID SS washers or steel, but not aluminum. Since the goal is to increase conductivity, an SS or steel washer isn't going to do it.

Didn't you say those jewelry washers were too thin?

Wouldn't it be easier to drill out the 2mm thick washers vs. using a washer that is too thin?

(BTW, go Vikings - 1.5 hours to kickoff)

To be fair, even a stainless one will still increase conductivity because you're still adding cross section to the equation. But it's definitely not ideal.

 

[Lt.Dan]

I made some washers for Michael to sell in his group buy with cells.

Lishen 270ah-272ah cell group buy.

I received my 8 271Ah cells few days ago (ordered last days of December, supposed to be CATL, but it does not say it anywhere) and was quite happy: they looked like new, undamaged, voltage ranging from 3.285 to 3.291V. However, when I started reviewing posts about top balancing and compressing...

diysolarforum.com

I laser cut them out of 1000 series Annealed Aluminum (absolutely dead soft, very conductive). They made a perfect fit and increased surface area to 3/4". But everybody thought it wasn't that great of an idea, and not too many were sold.

Another post about them https://diysolarforum.com/threads/lishen-270ah-272ah-cell-group-buy.14668/post-260217

 

[Stepandwolf]

I made some washers for Michael to sell in his group buy with cells.

Lishen 270ah-272ah cell group buy.

I received my 8 271Ah cells few days ago (ordered last days of December, supposed to be CATL, but it does not say it anywhere) and was quite happy: they looked like new, undamaged, voltage ranging from 3.285 to 3.291V. However, when I started reviewing posts about top balancing and compressing...

diysolarforum.com

I laser cut them out of 1000 series Annealed Aluminum (absolutely dead soft, very conductive). They made a perfect fit and increased surface area to 3/4". But everybody thought it wasn't that great of an idea, and not too many were sold.

If I ended up with welded studs, I will certainly contact you.

 

[Stepandwolf]

I grabbed this image from that other string. It shows that post diameter to be 11.11mm.