EVE cell terminal covers (3D printed) - Feedback welcome

[Mirlen]

I've been checking over my cells I received and doing a couple drain/fill tests and while waiting and waiting.... Saw a few options online but didn't like the fit/coverage so I decided to whip out the calipers and do some cell terminal covers of my own. Print them in black/red to make it easier to identify. I'm probably going to expand on these and do snap on covers for the bus bars as well with some varying width options but that'll take a bit of time. Recommend printing in ABS/ASA for heat resistance and just because I love ASA! (They are scaled for Polymaker Polylite ASA fitment)

https://makerworld.com/en/models/862847

I'd be interested to hear how these fit your cells. I tested these on a number of my EVE MB31 cells. I could probably expand to cover some other types given some time...
(Testing print, unlabeled polarity, final ones slightly modified)

 

[740GLE]

So they snap on the terminals, but dont snap on terminals that have bus bars?

Ones that accept bus bars (orange flexible ones) with maybe a poke test point (for your DMM readings) would be way more handy.

As of now I just cover my terminals and bus bars in kapton tape and it’s very messy.

 

[Mirlen]

So they snap on the terminals, but dont snap on terminals that have bus bars?

Ones that accept bus bars (orange flexible ones) with maybe a poke test point (for your DMM readings) would be way more handy.

As of now I just cover my terminals and bus bars in kapton tape and it’s very messy.

They go under the bus bars to cover the large exposed flat area and wrap around the edge of the terminal down pretty close to the top of the cell top. There is about 0.5mm of exposed height of the terminal for the bus bar to mate to. For testing, with these the bolts are exposed so can easily test on them. My plan is to extend the edges of the covers to have slots in them that a U shaped piece can snap into that will cover the bus bars/bolts completely and will have a small hole for a test point on each cell. Have to wait for my case to get here and play with geometry for that as I want them to have some spacing flexibility and then I'll have a few different widths to accommodate different width bus bars.

 

[740GLE]

Ahh that makes sense way more sense.

As one that doesn’t have a 3d printer, any interest in whipping up some and then selling them?

I’d gladly test them on my 280k ver 3 from luyaun.

 

[Mirlen]

Ahh that makes sense way more sense.

As one that doesn’t have a 3d printer, any interest in whipping up some and then selling them?

I’d gladly test them on my 280k ver 3 from luyaun.

DM sent.

 

[green mountain boys]

I never used a 3D printer. I looked at the link you provided and see that it takes over 5 hours to print a set for a 16s battery. I am curious what the approximate cost would be for the consumables?

 

[Mirlen]

I never used a 3D printer. I looked at the link you provided and see that it takes over 5 hours to print a set for a 16s battery. I am curious what the approximate cost would be for the consumables?

1 roll of Polymaker Polylite ASA is about $30 for 1kg, 32 covers uses about $6 in filament.

 

[hwy17]

Neat but I don't think it changes the tool drop hazard a lot and the whole bus bar area still needs to be physically well protected. I had an idea to cap the posts with protectors on mine but never bothered and wouldn't bother trying in the future.

 

[740GLE]

Neat but I don't think it changes the tool drop hazard a lot and the whole bus bar area still needs to be physically well protected. I had an idea to cap the posts with protectors on mine but never bothered and wouldn't bother trying in the future.

A bus bar cover those bare spots will be nice.

 

[Mirlen]

A bus bar cover those bare spots will be nice.

What bus bar widths are people using? My cells came with wide aluminum as well as the usual copper flexible ones. Aluminum measured 40mm wide and copper 20mm.

 

[mondurr]

I never used a 3D printer. I looked at the link you provided and see that it takes over 5 hours to print a set for a 16s battery. I am curious what the approximate cost would be for the consumables?

I just designed some for the older CALB 180Ah cells. Since I'm printing them with TPU (flexible / rubbery stuff), and you have to print slowly with TPU, it actually takes about 35 hours to print a full set of 32 covers. Material cost is about $8-$9. If you were to print these with a different material, such as PETG (rigid plastic), the material cost would only be about $5 and you could print a full set in about 15 hours. I prefer TPU for this type of application, however.

EDIT: Upon further reflection I looked up the fire safety profile of TPU and it is considered combustible while PETG is self-extinguishing. I wanted the flexibility of TPU for friction fitting, but for safety it does seem like PETG is a better choice. I'm now printing a test PETG version.

 

[740GLE]

What bus bar widths are people using? My cells came with wide aluminum as well as the usual copper flexible ones. Aluminum measured 40mm wide and copper 20mm.

I’ll measure them tomorrow they are the flexible with orange heat shrink.

 

[WISTEK]

Aren’t there very simple lids now? Why are they so complicated?

 

[chicagoandy]

I've been checking over my cells I received and doing a couple drain/fill tests and while waiting and waiting.... Saw a few options online but didn't like the fit/coverage so I decided to whip out the calipers and do some cell terminal covers of my own. Print them in black/red to make it easier to identify. I'm probably going to expand on these and do snap on covers for the bus bars as well with some varying width options but that'll take a bit of time. Recommend printing in ABS/ASA for heat resistance and just because I love ASA! (They are scaled for Polymaker Polylite ASA fitment)

https://makerworld.com/en/models/862847

I'd be interested to hear how these fit your cells. I tested these on a number of my EVE MB31 cells. I could probably expand to cover some other types given some time...
(Testing print, unlabeled polarity, final ones slightly modified)
View attachment 261710

View attachment 261708
View attachment 261709

Looks great. I've been thinking about something similar, but with clamps down on the side of the battery, to help ensure the terminal weld isn't over torqued. I wonder if anyone has seen something like that.

 

[samwhammy]

Looks great. I've been thinking about something similar, but with clamps down on the side of the battery, to help ensure the terminal weld isn't over torqued. I wonder if anyone has seen something like that.

I put grub screws in and torque a nut instead of using the provided screws. You could run a piece of wood down the length of the assembled battery next to the posts. Someone could hold it while you torque the bus bars. I used a 1x4 on the top to hold them before I switched to grubs. I found a few non 90 degree welds on a few dual screw post EVE 304's also! I use them as the first or last battery depending on which terminal is off. So far I have found 3 this way out of 64. I like this cover. Not my battery! I turn the flex down and use 2 grubs per battery. Kind of defeats the benefits of 2 connection points!

 

[samwhammy]

I modified and used these for a build. They work great also. Print a terminal cover first then update to fit! Too tight when using ABS or even PETG! I had to up the size for X and Y 1% but the height Z is perfect left at 9mm. I use OrcaSlicer and Creality K1 Max's with no glue and texture plates. I use a dryer at 65 degrees to dry and preheat all filament. Pretty perfect 1st layers every time after leveling the bed with spacers. I am looking for a resin 14k abs printer for precision parts. Anyone using an anycubic or other printer for resins?