Some features require an Apple ID terms apply.This is a purely hardware problem and system reinstall or upgrade is NOT necessary. The MacBook remained fast and the cursor movements, from the touchpad or mouse were still smooth after several minutes.Ĭonclusion: If the battery has the 'replace now' status, some artifacts totally paralyze the MacBook Pro, although it appears working correctly during the first seconds. This battery was in better condition (with 'must be checked' status, but didn't had yet the 'replace now' status. The battery connector is not a the same location, but is same, so that I could insert it and hold the battery with my hand. Both batteries operates at the same voltage (although thus of the 15'' has higher capacity).

Lastly, I tested the MacBook with the battery from a 13'' inch (A1278) MacBook Pro. This happened even when using softwares from Apple only and not from third-parties. The MacBook was fast during the first seconds and then went slower and slower. Then, I reset SMC and NVRAM, following the procedures linked by users Nimesh Neema and Amey. This had the positive effect that afterwards, the date/time were remembered, although the battery was in very poor ('replace now') condition. I first followed this procedure in the comments of a video showing how to fix battery issue on a MacBook: Long version or how the problem has been identified. Specifications : Processor i7 2,3 GHz with 4 GB RAMĪfter thorough tests, I came to the conclusion that the jerky cursor movements and the MacBook coming slower and slower was caused by the battery with 'replace now' status. The battery is no longer charging and the time (date/hour) is no longer remembered, so that I have to reset it after each start of the OS. Practically, it is impossible to use the laptop. The one of the touchpad is also jerky, altough to a slightly less extent. Then, performance suddenly dropped and all menus now take a while to open. After the upgrade, the laptop was running smoothly during about 1 week. I have a MacBook Pro 15'', A1286, Early 2011 which was running OS X Lion and became extremely slow few weeks after an upgrade to El Capitan.

Macbook pro gpu 2015 slow el capitan