Neat design, but like others say, A123 discharge characteristics make reading voltage not very effective.

There is a new product out that is designed to work with A123 batteries. It measures consumed amperage of 2 batteries. Its called Intelliswitch. It looks like it has potential.

I don't have a turbine....yet, but I plan to try one of these switches in another plane. If it works I will use it in my "soon to be bought" turbine jet.