A recent 2,245 mile trip inspired benchmarking and generating this graph: Drive segments lines at 40, 60, and 80 mph intersect at zero with the charge curve. Limited to 3 hours (180 minutes) of driving Maximum 30 minutes of charging in 10, 20, and 30 minutes A horizontal line from one of the three speed lines to the charge curve gives the total minutes for one driving segment, the sum of driving time and charging time. For example, driving at 80 mph for an hour: -60 minutes to drive 80 mph +8 minutes to charge for that distance at that speed 60 + 8 = 68 minutes for that segment 80 mi * (60 / 68) = 70.6 mph equivalent speed combined driving and charging Driving at 80 mph for an hour with required charging, the block-to-block speed will at best be 70 mph or 70 / 80 = 87.5% of the EV driving speed. This leads to a more useful summary chart. Here is a chart of block-to-block, speed efficiency: 80 mph has the worst block-to-block speed efficiency, 80-87%. 60 mph is better, 84.5-90.5%. 40 mph is best, 100% within the 3 hour limit. Full Self Driving (FSD) does excellent night driving which is typically cooler and has minimum car traffic and mostly professional driven, tractor trailers. Leaving around midnight and driving for 12 hours, arrives around checkin time at a distance motel. Fortunately there are tractor trailer companies, especially moving vans, that limit their cruise speed to 65 mph. This suggests an optimal EV strategy: Get on Interstate in "Chill" mode at 60 mph When a truck passes at 65 mph, set "Chill" mode speed to 67 mph Stay in lane to follow truck Full Self Driving keeps a safe distance behind, not tailgating FSD nag keeps your eyes looking for any road debris to avoid Truck serves as camouflage so other traffic avoids tailgating Larger truck rear lights improves visibility to following traffic minimizes a rear end collision WARNING - have quality anti-rock film on windshield Charge at every charger on way for fastest block-to-block speed Add miles to next SuperCharger plus 30-40 mile reserve Exit and return segments can't be helped but frequent breaks are good for the human monitoring FSD at night. A lot of miles will be covered without a lot of fatigue and minimum risk. Bob Wilson
Correct but I have tricks: I follow trucks - the commercial driver sees further and higher than me. Truck rear lights in addition to mine FSD - cameras see better at night than humans. Nags - requires the driver to look out the windshield except for short glances Safe following distance - time enough to steer around debris These make night driving “less bad.” Bob Wilson
I use the same trick driving through tulie fog. The semi-rig is my battering ram. I've almost hit idiots dead stopped in the middle of the highway. I now slide behind a semi-rig; though we should've both pulled over to wait for the fog to lift or dissipate. I don't like pulling over, seen too many drunks plow into road crews in broad daylight under clear conditions.
The Northern end of I-81 in central Pennsylvania can be pretty exciting too. Hill tops that ascend to cumuli-granite clouds. Bob Wilson
A few days ago, my iPhone in "Time Lapse" video, one frame every 6 seconds, was on a tripod recording the diagnostic display while charging from 13 miles to 180 miles range: This is first frame showing the V4 SuperCharger at 407 VDC and 0 amps. This was without "preconditioning" the battery after driving nearly 200 miles on a hot day, 100 F. In effect, the battery temperatures were consistent with highway speed driving. I then recorded the data in this chart: "A" - initial peak voltage, 374 V, and current, 463 A There may be a chemistry transition "notch" "B" - when the charge reached the peak battery voltage-current The subsequent charge voltage and current were driven only by the battery characteristics "C" - the first distinct chemistry "notch" The literature describes how there are internal transient points in voltage-current curve "D" - second distinct chemistry "notch" "E" - ending chemistry curve Nickel Cobalt Aluminum (NCA) charging dynamics are described in two papers: Calendar Aging of NCA Lithium-Ion Batteries Investigated by Differential Voltage Analysis and Coulumb Tracking Aging mechanisms of cylindrical NCA/Si-graphite battery with high specific energy under dynamic driving cycles My $9k replacement, 2019 Model 3 battery pack replaces the original that began failing in the early Spring at ~150,000 miles. A bad valve in a "5-way" coolant bottle probably "cooked" the battery into early failure. Furthermore, Tesla no longer makes NCA 2170 cells used for Model 3 having moved on to LiFeP battery chemistry. This is one of the last NCA battery pack that will ever be. So I want to understand my battery aging mechanism to maximize the life. These charge curves led me to understand shorter drive segments between SuperChargers is the fastest way to reach my destinations. I now charge enough to reach the closest SuperCharger along my route with a 40 mile reserve: 1-10 minutes - maximum charge rate for least amount of time per mile of driving. Typically 1-1.5 hours of driving. 11-20 minutes - seeing a fall off in charge rate means a longer percentage of the driving time is spent waiting for a slower battery charge. Usually 1.5 to 2.5 hours of driving. 21-30 minutes - even slower charge rate reduces the block-to-block time as a greater percentage is at a slower charge rate. A maximum of ~3 hours driving. Bob Wilson
