I have the above track saw on its way to me without batteries. Instead of the 5 Ahr batteries suggested, I plan to use two 4 Ahr batteries. Festool says in can be operated on one 5 Ahr battery, so I’m assuming two 4 Ahr ones should work fine. Can someone comment on this pls? I seldom use my track saw for more than 4 or 5 cuts at a time. Thx, John