MagSafe battery disassembly confirms dual cell design

A teardown of Apple’s new $ 99 MagSafe battery from Charger Lab gave us our best look yet inside the new accessory and revealed more details on how it works. For starters, this confirms recent speculation that it uses a pair of series-wired battery cells like Apple’s previous Smart Battery boxes, but it also gives us a glimpse of the NFC circuitry and thermal shielding inside.

A two cell design is important because it allows the battery voltage to be higher than a comparable single cell design. While each individual cell is labeled as 3.82 volts, the overall battery voltage is 7.62 with them wired in series. This means that the pack should be able to deliver more power than its 1,460mAh capacity suggests compared to the battery capacities of the iPhone itself, with a total output of 11.13 Wh. Appleinsider has good science writing if you’re looking for more detail.

Screenshot: Loader lab

Beyond the battery cells, disassembly gives us a good look at how the battery dissipates heat. In February, when Bloomberg first reported the existence of the pack, he noted that development had been delayed because the iPhone software kept thinking that the accessory was overheating. It is not known if this issue was fixed with software or hardware fixes, but it is clear that a lot of effort has been put into keeping the pack cool while still allowing it to provide enough power.

Unlike the right to repair advocates at iFixit, Charger Lab does not offer a repairability score at the end of its teardowns. But the amount of adhesive and concealed tabs that hold the battery together doesn’t make it very easy for the user to maintain. We will have more details on its performance in practice in our next review.