G'Day NR,
Dunno if this is of any use to you, but according to the R44 parts catalogue, serial numbers up to 0945 have the battery in the engine bay while 0945 and subsequent have it in the nose.
I had a quick look in the maintenance manual and couldnt find any further info, but it was only a quck look due to time constraints. I wouldn't expect any great dramas shifing the battery to the engine bay, however you would need to have a new load data sheet issued.
Hope this helps.
