A multi-engine system 10 for use on an aircraft 14 is disclosed. The system 10 may comprise a first aircraft engine 16A and a second aircraft engine 16B configured to drive at least one device 12 of the aircraft 14. A starter 20 may be coupled to one of the first and second aircraft engines 16A, 16B to assist starting of the one of the first and second aircraft engines 16A, 16B. An energy source 24 may be configured to deliver energy to the starter 20 at a rapid rate during rapid starting of the one of the first and the second aircraft engines 16A, 16B, the rapid rate being higher than a regular rate used during regular starting of the one of the first and the second aircraft engines 16A, 16B. The energy source 24 may comprise at least one supercapacitor.