1. No, that's no necessary, however, might be more prudent to discharge it more, see other answers.
2. Yes, you don't need it plugged in all the time, however, do not charge it to 100% all the time if you don't need it. Spending time at 100% reduces battery life, spending time at a lower charge level increases battery life. The lower the average charge level, the better.
3. Absolutely. Only charge it to 100% if you think you need all of 100%. If you don't then try not to. So you go in and out a couple of times. Maybe you charge it to 100%, then you use it in the morning, don't recharge back to 100, use it again, and then now its a lower charge level and you've used more of the charge and less cycling back to 100%. Let say after the first use you see you have 35% left. And you know you need to go for another trip but need about 60% battery, then charge it to 70%, go on that trip, and come home with 0 to 10% charge. Wait as long as possible before recharging, better to charge early morning like 5am instead of right away when you get home from the 2nd trip at 7pm. Again, less time dwelling at 100% charge level. You can program value charge to charge later or you can plug it in when you wake up in the morning, whatever works for you.
4. I don't think so, damage is irreversible. Its also additive, so a little bit of damage here and there adds up to something noticeable. Try to not use the battery alot, especially during hotter weather, and charging and discharging it raises the battery temperature, and spending time with elevated temperatures damages the battery slowly but surely. Also try to spend an hour to drain the battery, not 10 minutes at 70 mph on the freeway. Use city street, go 30 to 40mph. Less strain on the battery and less temperature rise.
5. Not particularly, its going to continue but you can expect to accelerate degradation if you do the wrong things or slow it down it you don't. Things that degrade the battery, 1. time (can't help that), always ticking always degrading. 2. charge level, the lower the average level, the slower the degradation. 100% is worse than 80 worse than 60% worse than 20% etc. If you don't intend to use the car the next day, then don't be afraid to leave it sitting at 10% charge level after you used it that day. Better than recharging it to 100% and letting it sit for 2 days at 100%. Only exception is don't let it sit empty in hybrid range. If drain it all the way, the recharge it right away when you get home to somewhere around 5% and disconnect charger to let it cool down first. 3. Number of cycles, they are finite, don't expect unlimited cycles. Better in my opinion to combine 2 to 3 trips per charge, so 100, to 68, to 44, to 21 and then recharge rather than 100 to 68 to 100 to 72 to 100 to 77%. 4. And most importantly, heat. Using the battery more often during the hot weather and alot of in and out trips with recharging back to 100% with L2 is worse than using it less often and recharging with L1. L1 doesn't give you that luxury of going in and out several times a day and hence in an indirect way helps you to keep the battery temperature down. Having L2 at home in my opinion backfires and kills batteries faster, especially for the smaller pack that we have (7.6kwh) The more elevated it becomes, the more the damage. On hot days you may not want to recharge the battery more than once and wait until the early morning hours before recharging it again.
6. I have 63+k miles on my Cmax with about 36k of which are battery miles. My battery is still OK, degraded from new for sure, but still can yield about 5.4kwh per charge. When it was new I remember getting 5.9kwh out of a charge. But its 3 2/3rd years old now too so I can't expect it to be 100% of original.
7. Read all above, should help plenty!
Right now my car sits at 29% charge. It was at 50% charge earlier today and I had to go out to the grocery store and back this afternoon. Its not plugged in as I don't have any plans for it for tomorrow at the moment. Don't feel like you have to plug it back in as soon as you get back home.
Edited by rbort, 30 January 2017 - 05:50 PM.