battery level protection

Hi Guys what should i set the battery first and second level protection at
on a flame wheel F450 and Naza lite gps

The thing to do, is try it. Fly until you get the red flashy low batt warning, then stop flying and recharge. See how much you have to put back in the packs.

If you have 3300mAh pack, you want to be putting about 2500mah ish back in when you charge.

As a guide, I have mine set to 10.4v, with a voltage drop of 0.4v...

Alternatively, you can disable it, and use a timer like you would with any other electrical model...