Using the old slightly damaged 45 W Magsafe 1 charger from the MacBook Air to charge the 15-in MacBook Pro. It's supposed to use an 85 W charger.
Prior to fitting an SSD to this MBP, attempts to charge it with a 45 W charger would fail, although the battery wouldn't discharge further. The SSD has a much lighter power load than the HDD, it's now possible to fully charge the MBP with the MBA's charger.