RE: Dual Batterey Pack connection
Just to further to expand on Michaels comments. I have also performed a cross charge test, and got the same results. In a 20 minute flight, you will never deplete the good battery, assuming that you fly like most everyone else and leave a 2 or 3 flight reserve at your no-fly voltage. There is a cross charge that takes place, but as Michael its insignificant. You would also notice the bad pack when you did your pre/post flight checks, but would not even know you had a problem in the air.
Others have done similar tests, and came up with the same results. It takes hours to deplete the good battery with cross charging. So as long as you do a ESV check before each flight on each battery, you will catch it before it causes you any problems.