As far as how secure the new battery needs to be, that got me wondering too. My guess is that it is such a tight fit - on all sides and surfaces! - that it would be fine. The one potential issue I see is the battery moving too close to the KBD cable's ZIF socket on the logic board and adding pressure to the connected cable end. You'd have to drop it or bump it pretty hard for such movement (with adhesive essentially failing to allow that movement), but if kbd fails after such a whack that would be the first culprit to look at.

Agreed on logic board alignment! I will have to remove and re-set the new battery just because of this, and may have broken the KBD connector along the way already...

The adhesive on my A1502 unit may as well have been epoxy! It took forever to get the segments separated, and several times I had to apply enough leverage that I thought I might break the battery or bend the case. Getting the dissolver in works, but you really need to make sure it actually reaches the adhesive through the cracks, so it's dabbing and levering, repeatedly... I used another vendor's battery replacement (CSEXCEL), and that one's adhesive was much much weaker.

Guys, I followed the procedure diligently, but so far ended up in failure. I have an A1502 MacBook and bought another vendor's battery for swapping in. I've had this guy since 2016, so 8 years of decent use. It started having KBD issues two years ago, and that was the first "fragility" I needed to keep in mind. Swapping a new KBD cable in and figuring out how to get the back rescrewed on without moving the cable enough to lead to failure again was a trick in itself, but I fixed it, and battery was next. That battery is really glued in tight, and the new battery had some slight size differences here and there that meant not an exact fit, but OK. KBD cable failed again, solidly this time, with battery too close to the ZIF socket now. SO still trying, with yet another kbd cable on the way and needing to reposition the new battery for more cable socket clearance. If doesn't work my laptop is toast. My conclusion is a big item like a glued in, multi-piece battery may not be worth the trouble to swap.

This does look difficult and tedious. Steps showing adhesive removal and re-application would be quite helpful. My iPad mini 4 (A1538) battery is showing signs of age but I think I would wait quite a bit longer based on the riskiness of damage at various stages that I read here. Still, given the cost from Apple ($300) to repair this sucker for me I think I would eventually give it a try regardless, but maybe with the hair dryer method for adhesive softening. Battery replacement cost from Apple is close to what the entire device originally cost!

So far it is just the case for mine that seems broken - It won’t charge the buds properly. I really don’t mind cosmetic damage if I can replace the case’s battery (assuming that is the culprit). Where might I get a replacement battery? Also, if I used enough care, could I not just cut into the case closer to the battery to get at it from underneath?

How about screen replacement? Is there a replacement part for that?