Part number for 3M VHB tape used for DIY battery banks?

[RobBehr]

Hi Folks, This topic has been discussed, but never to a specific conclusion. I'm building lithium ion battery banks using Lishon cells and want to duplicate Will's technique. He mentions "VHB tape" as the double-sided tape he prefers to stick the cells together, but there are many different VHB types made by 3M. For instance, some are thin and others are thick. The foam in the tape is compressible, so thickness is a factor beyond just spacing. Does anyone know the specific model of 3M VHB Will uses for his battery builds? Thanks, Rob

 

[MisterSandals]

If you permanently tape them together you will greatly reduce your ability to work with the cells. What if you need to redo a top balance? Or want to move cells around to better manage them or test how their position affects the overall battery?

Unless you have a compelling reason to stick the blue plastic coatings together, I'd keep them as is but maybe separated with a thin resistive material.

I will add, you should really compress your cells somehow. This will pretty much keep your cells together which sounds like your concern for some reason. Taping the cells does nothing to alleviate stress to the terminals, especially if your cells undergo any expansion.

 

[Samsonite801]

I would rather clamp the cells before I would want to stick them together with tape. I went through this already. I bought some stuck together cells from a vendor, decided clamping them is a much more effective approach (in my mind's eye anyways), decided to pull them all apart, use Goo Gone to remove all the tape, 10 hours later I finally got all the cells clean. Man I wish I didn't have that tape ever on them...

 

[Gazoo]

The foam in the tape is compressible, so thickness is a factor beyond just spacing. Does anyone know the specific model of 3M VHB Will uses for his battery builds? Thanks, Rob

Not to sound mean but even if I knew I would not post it. You are asking for all kinds of problems taping the cells. Very bad idea. The other suggestions to mount the cells in a compression fixture is the correct way to treat the cells.

 

[RobBehr]

Will mentions being able to pull them apart. I don't want to use something truly permanent. I'm hoping there is a variety of VHB that uses an adhesive similar to Post-It notes, which are removable.

 

[Samsonite801]

Will mentions being able to pull them apart. I don't want to use something truly permanent. I'm hoping there is a variety of VHB that uses an adhesive similar to Post-It notes, which are removable.

This is why to me, clamping is superior. Clamping keeps the cells from bulging in time by holding some pressure on the cell cases, it also keeps the cells tight enough so movement or vibration in a mobile situation doesn't stress the bus bar links and connector bosses, weakening them, makes transporting solid (not like moving around a flexible blob of jelly), and is really easy to take off the clamp and disassemble if needed, etc. Also gives a nice plate on the bottom to stick heat pads to, so the heat blends out without creating hotspots. And I can just throw the whole battery pack (in clamp ass'y) onto a handtruck dolly and move it as a solid unit very simply (and know my pack won't get damaged in transport)... Just tip it up on its end and scoop it up with the dolly and off I go.

 

[HRTKD]

The cells need to be compressed. The compression frame I'm using does a fine job of preventing movement of the cells. I have nothing between the cells. No spacers, no tape, no air.

While the cell compression isn't supposed to be overly tight, snug is enough and that's also sufficient to prevent movement. Using tape between the cells could add space that, in my mind, defeats the purpose of the compression frame. I don't want the cell walls expanding. Any expansion puts stress on the cell terminals since I'm using bus bars.