Max EV range on 2017 and 2018 Prime

Agreed. Our 2018 Gen2 Prius PHV still does 45 km (28 miles) on a full charge. It's done about 50,000 km (31,000 miles).

Interestingly, after 40 months since purchase of the EV, our battery seems to have a slightly increased capacity. While this possible, small increase (approx 5%) might be due to temperature/season/etc. it does suggest that the battery hasn't lost capacity over this period.

 

Too soon to be sure but I fear I'm having similar experience. I bought my 2018 Prius Prime Advanced in August 2021 with only 7480 miles on the odometer and lifetime ODO mpg of 57 mpg. indicating vary little home charging. (my ODO miles per gallon now at nearly 24,300 miles is in the 160 mpg range the last time I looked. I mention this to indicate home charged battery usage.) I do fully charge after each trip and am beginning to fear I am tiring the battery by having it often near full charge in the garage. Actual data: I have a record of every charge, with mileage and miles per kWh, since I bought the car. Last summer I was regularly getting 6 miles per kWh--driving in a rural setting mostly at 35 to 45 mph. With recent cold weather that has dropped to a little over 5 miles per kWh and last month to 4.95 per kWh. It is now warming up in Asheville and I'm back to around 5.5 but have only gotten near 6 miles per kWh once on a warm day with ideal road conditions. I'm guessing that elapsed time is more important than actual mileage regarding battery degradation. (I still got 60 to 66 mpg when running in hybrid mode on my last out of town trip in November but 99% of all local travel is in EV mode.) Don't know how helpful this is but it IS REAL data computed with a PN-2000 watt meter when charging and not depending on the car's report. (The last full charge from base level took 6.15 kWh so have seen little change there so far.)

 

A "full charge" of the battery only brings it to 85% and a "complete discharge" brings it down to 15%. You're not hurting it by "fully" charging it daily. Being in the garage is actually good. Being at 85% with the windows closed and baking in the sun the whole day is worst as a battery can't accept as much charge when hot. I don't have the exact number but a battery at 85% baking at 50-60°C (hot tap water temperature) in the sun might become overcharged, which is bad.