MacBook Pro 2.7GHz 15" Mid-2012 Unibody, A1286 I have a very strange problem with batteries. My initial Apple battery lived for 2 years and then got bulged. I usually use a laptop in “room conditions” but prior that day I traveled for 1-2 days in hot conditions (about 86 Fahrenheit) — if it matters (I think it doesn’t, see below). I then replaced my battery and did so multiple times after each subsequent battery eventually also got bulged. Here is the summary of batteries I installed in chronological order: Reportedly “original” battery with replaced power elements (cells), listed as “new” (not on eBay, it was supposedly “trusted” seller). The quality of these cells is unknown but they gave only 3 months warranty on these batteries. Battery lasted 1.5 years and got bulged. “NewerTech NuPower Battery” (https://eshop.macsales.com/item/NewerTech/BAP15MBU78W/). Battery lasted 10 months and got bulged. The same battery as in “1”: this time battery did not bulge, but it just stopped working after 6 months. It supposedly got blocked by internal battery controller, but the reason for this is currently unknown. The result was that laptop did not work off battery, and only worked stable off charger with the battery removed or with another battery installed. So after 5.5 years, I have 4 broken batteries, 3 of which got bulged, 1 of which was original Apple battery. I mostly kept laptop plugged to the charger 24/7/365, and worked off battery quite rarely, but with 3th and 4th battery I discharged them regularly once a month I was told that possible reasons might be: crappy batteries battery overheating logic board issues I am aware that in recent times even trusted manufacturers like NuPower is no longer as good as they used to be, and there are almost no truly “original” batteries being sold, so the odds to get a “crappy” battery are significant (https://forums.macrumors.com/thread...s-nupower-vs-ebay-amazon-experiences.1816882/). Also MacBooks, in general, may run quite hot, so overheating also may be a valid point. But I can't see that this is a massive global problem. A huge amount of people buying all kinds of batteries and have no issues, while I have original Apple battery which got bulged after 2 years. Also their MacBooks are as hot as mine, but they do not get bulging batteries (I did not notice any heat-related issues with my laptop). I got my logic board tested/checked multiple times by multiple service engineers and no issues were found. Currently, I am looking into installing the original battery with Apple repair service to check if the reason indeed is in logic board, and I have a strong feeling that I might get same problems with this battery in the future. ========== What is your opinion on this? How probable is that all 4 batteries were faulty to break in such short time? Did you have any related experience?