Start up in cold weather: Helicopters
As a helicopter pilot, there are frequent instances when I need to start up on 'internal' battery in remote heliports. The issue crops up at lower temperatures (+15 degrees C or below) when the 'cranking' and initial acceleration of turbine isn't adequate resulting in high exhaust temperatures in some cases.
Here's the question:
Are there batteries in open market that can hold adequate charge to provide acceptable cranking even after prolonged parking in lower ambient temperatures and facilitate a flawless start (considering helicopters upto a weight class of upto 7000kg). If any, will these be safe to operate at higher temperatures of upto +50 degrees C.
Just that it doesn't go unsaid---We may exclude on board APU start option from the discussion.