LiPo power system was tested in anger over this weekend on a film shoot. The battery pack, when fully charged, should register at roughly 16.8v. I’m getting about 16.78v on a 0.8A balance charge, so I’m pretty happy with that. For a full day shoot, running the SD552 mixer with a boom mic and a pair of Lectrosonics UCR411a receivers, I was down about a volt by the end of the day so at my reckoning, it barely broke a sweat. Full charge on each LiPo cell is 4.2V and terminally empty is about 3v per cell (operation at a level any lower than this can damage the cell pack). With my 4-cell pack, the no-go voltage is therefore 12v which gives me an operating voltage-drop range of about 4.8v. Minimum operating voltage of the equipment is roughly 10v. Another neat feature of this solution is that the SD552 has a battery check meter built in which is set for Lithium battery operation and the Lectrosonics UCR411a receiver has a built-in digital voltmeter which tells me the exact voltage of the input supply. Can’t argue with that.