So yesterday my 17" pre-unibody MBP didn't want to turn on. I connected it to the power adapter and when it booted finally to the desktop i noticed it was not charging and it advised to replace the battery. When i took out the battery you could see that the battery pack in the middle had swollen because it already had lifted up the outer shell. I thought of trying to pry it open and succeded this morning with the right tools. These are the packs used: There are 6 units in total connected 2x parallel(making 6400mAH) and 3x series (making 10.8V nominal=3x3.6V). The outer packs are actually still measuring fine and are not swollen but if i can find cheap enough quality packs i would like to replace them all. In my research they seem to be made by Amperex (ATL). It seems they are one of the few bigger names as battery manufacturer being others LG chem, Sony, Panasonic. Looking for lipo 6052103 there are obvious search results which are leading to aliexpress and similiar with prices from 7-12€ per unit. Did anyone find a good source for quality ones. Maybe even from the original manufacturer ATL or the other big players? The batteries are measuring 102x50x5mm. I'm aware that i can buy a replacement one but i rather have some quality one so here in spain i only see the newertech ones for about 90€ without shipping so if i could find for half of that individual packs from a quality brand i would rather do the DIY way.