If you are now using aircraft battery as your "standard" source of power for starting you might want to suggest to your engineers to look for a PWC document (maybe an SB or SIL-can't remember) about damage to your engines over the medium term due to low voltage starts.
It was an investigation that PWC had carried out in conjunction with AW and the conclusion was issued in this PWC doc mentioned.
I would suggest that you look at addressing your ground power issue sooner rather than later. Best of luck.
