Chosen Solution
I bought a replacement battery kit for my 2015 13” MBP, and while the swap went fine the adhesive that came with the new battery has failed / isn’t strong enough to hold the battery in place. Because the battery is soft cell it doesn’t feel safe to not have it secured to the frame. What is a good solution to adhere a soft cell battery to the aluminium frame that will be strong and won’t cause any chemical issues with the battery over time?
This is tricky! The space you have to work with is so very little! Let’s first look at what Apple is trying to do. They want enough room for the battery to expand and shift a bit as it cycles. So it’s important not to use anything that is thick as the space needs to be reserved for the battery to expand into. The adhesive also needs to be removable so the battery in the future can be removed. So what went wrong? So we need to first make sure the area is fully clean of the old adhesive and other debris (dust and grit) and don’t touch the adhesive with your fingers as these will interfere with the adhesives adhesion! The solvents you use may leave a film which then interferes with the adhesives adhesion. Low quality isopropyl alcohol often have junk in it so its important to use reagent grade isopropyl alcohol. I personally use Goof Off to remove the visible adhesive traces and then use 95% isopropyl alcohol to make sure there is nothing left on the surfaces. OK, but it’s too late now the adhesive is dirty and not holding. How do I fix this? Taking the battery out and cleaning off the adhesive on both surfaces is about all you can do. You’ll want to tape around the pad areas so the solvent and adhesive doesn’t drip between the cells and wiring. Then applying a fresh set of glue pads which is nothing more than double stick bonding tape which has good adhesion. Its’ important the carrier tape is thin and the adhesive its self is not overly thick. 3M offers this bonding tape which is what I use 3M Scotch ATG Tape 924. Make sure you get the correct width and just cut off the needed strips which are slightly larger than what you have now for pads. The last Step! HEAT! The acrylic adhesive is temperature sensitive! So a cold surface won’t bond effectively. And you do need a bit of pressure as well so the surfaces are held close together. As crazy as it sounds I use a small medical heating pad to place the system on (lid open) so the keyboard is resting on the edge of my desk when I have the heading pad under it then I rest some weight on the batteries so they are pressing down to the uppercase which is being warmed from below, a few hours is often all that’s needed to make a solid bond between the battery and case.
