To answer your questions, on #1 its said to be 14.5% from people with the SG, a little too low in my opinion, should be 20%. An empty HVB is about 21.5% from what was said in posts. On of my friends saw that the batteries drop out of balance the worst when the hybrid battery is 1/2 way down. Something to keep in mind.
The top end is 4.10v per cell, 100% would be 4.20v. As far as percentage I'd have to double check but I believe 4.1v is around 93%. Limiting at 4.1v should help with heat voltage rise not to go over 4.2v, but heat is still not good for batteries hence why I said park in a garage or in the shade if outside would be best especially in the summer.
I agree that these batteries will last less in hot climates compared to colder climates. It may be one of the reasons why Ford warranty for the battery is 8 years 100k miles in some areas and 10 years 150k miles in others.
One way around the charging is to program value charging to kick in at 3am so your car will be ready at 5:10am or there abouts from completely empty on 240v. It would just be a habit instead of charging in the evening and having the battery 100% full for 10 hours before you leave, you could make it ready on departure using this feature. Not sure how much difference this will make, 10 hours is not a long time at full charge but it could help over the years. Plugged in 24/7 in my opinion would be worse.
During the week, I'm going to charge one of our Energis on the 110V charger, at least some of the time. In that way, it will top off just an hour or two before our start times. (I only have two outlets that will reach the cars outside & in the garage, on the same circuit, and charging two Energis at once on 110V blows the circuit breaker.) By rotating which car gets the 110V, I'll probably reduce battery stress a little and at the same time have both cars ready at the crack of dawn.
The Ford warranty, at 8 years/100k miles or 10 years/150k miles, is interesting and surprising. Here are typical discharge cycles versus depth-of-discharge for Lithium Ion batteries; most sources list something similar:
Depth of Discharge Discharge Cycles until battery capacity = 70%
Edited by P=E/t, 06 April 2015 - 06:33 PM.