Interesting that it has an APU, never met one of those before, I don't believe it was original manufacturer's equipment, we just had to have a very large GPU that pushed out large amounts of 400cps power to start the engines with, you might just get one started on the battery with much juggling of the HP cock and fuel trim switch, if you were lucky.
The one I travelled on (standing behind the FO!) had difficulty starting the first engine (right outer). Can't remember if we had a power cart, but I remember the captain cursing a bit try to coax it into life (we could see it plainly in the reflection in the glass of the pier at Manchester).
Once he got that one going, starting the others was no problem.
SSD