SuperCharger metrics

I didn't like the quality of my first report so I repeated it using iPhone, 'TIME-LAPSE' to record the session:

• YouTube controls
  • SPACE - Start/Stop
  • "." - Forward one frame
  • "," - Back one frame
• Standard Range Plus Model 3, V19.16.2
  • climate control was off
• 20 mi indicated battery range at start
• 237 mi stopped recording data in spreadsheet
  • frame numbers to reconstruct true time
  • kW rate
  • mi/hr rate
  • battery mi
  • cost
  • first and last frame times

Here is the battery range in miles during the session:

One goal is resolving the optimum charge session for cost and speed, the green dashed rectangular box:

• too short duration - the ramp up slows getting back on the road. It is cheapest BUT a slower trip end-to-end speed.
• too long duration - the battery taper slows getting back on the road. It is also more expensive while giving a slower trip end-to-end speed.

Adding the charge and travel time at 65 mph with the distance covered gives a curve showing the optimum, battery charge:

What this means is attempts to charge to the vehicle maximum range is both expensive and causes the trip to take longer. It is slightly faster and cheaper to go shorter distance, SuperCharger-to-SuperCharge when in SuperCharger mode. This does not apply on the first trip of the day leaving with the car at maximum charge.

This busy chart combines the costs and battery mi level with the X-axis, charge rate:

• $0.025/mi = $2.50/100 mi - optimum route, expected cost. With gas at $2.50/gal, in effect, 100 MPG equivalent.
• longer distance legs will give a slower trip time and higher cost but if you have to reach a SuperCharger, there is only one alternative . . . slower speed than 65 mph. But it will be faster than stopped or using an L1 or L2 charger.

On long range trips that require multiple SuperCharger sessions, there may be more than one route. Choose the route with the closest SuperChargers and do multiple, short charges. Avoid routes that have a lot of maximum range segments.

Bob Wilson

 

Source: Tesla Model 3 Sets New EV Cannonball Run Record of 50 Hours, 16 Minutes - The Drive

Total time: 50 hours, 16 minutes, 32 seconds
Total mileage: 2860 miles
Charging cost: $100.95​

So:

• 56.90 mph ~= 2860.7 mi / 50.276 hr
• $0.0353 / mile ~= $100.95 / 2860.7 mi

Hummmm, AutoPilot and I might come close to matching their record. I'll have to model it. My Standard Range Plus Model 3 is about 150 lbs lighter but they could have had a higher, peak charge rate, ~120-150 kW and I know how to drive the weather. Tape the joints, air up the tires, optimize the schedule, and it might be close.

Bob Wilson

 

Preliminary data suggests this approach works.

Bob Wilson

 

Back of envelope:

• 786.8 miles
• 15:11 (15.2 hrs)
• $24.92 SuperCharger
  • $5.50 home charge
  • Free at Red Roof Inn

My model does not include the distance and slower speeds between the Interstate and urban streets to SuperChargers. It also does not include the traffic backups. However the GPS data should give me a basis of estimate.

With gas at $2.50/gal, ~78.7 mpg SuperCharger fees for this trip. Home charge is offset by free Red Roof charge. More details to follow when I get home.

Bob Wilson

 

The return trip and graph. I made one mistake of using the built-in, Tesla trip planner which insisted on one long segment near the limit of range:

	date	location	T1 =<60kW	$T1	T2 > 60kW	$T2	mi to next	hours to next	mph	T2%	cost
1	06/21 14:00	Munro		$0.00		$0.00	96	1.9	50.1	0%	$0.00
2	06/21 15:55	Maurnee	16	$2.24	13	$3.51	143	2.6	54.6	45%	$5.75
3	06/21 18:32	Dayton	29	$4.06	15	$4.20	164	4.7	34.9	34%	$8.26
4	06/21 23:14	Louisville	3	$0.45	14	$4.02	114	1.6	72.0	82%	$4.47
5	06/22 00:49	Bowling Green	14	$1.96	14	$3.92	79	1.7	46.9	50%	$5.88
6	06/22 02:30	Brentwood	6	$0.90	7	$2.03	102	2.0	51.0	54%	$2.93
7	06/22 04:30	Home	365	$4.48		$0.00		0.0	0.0	0%	$4.48

• maximize T2 (>60kW) for fastest speed and lowest cost
• Tesla trip planner tries to maximize charge which is the worst for speed and cost

This chart shows what happened on each leg of my return:


Sometimes to reach the next charger, you'll have to use the more expensive, slower, Tier 1 rate, less than 60 kW. However, it may make sense to reduce the cruising speed to achieve a greater block-to-block speed and reduced cost. Stay tuned for this analysis.

Also, it is important to arrive at the next charger with the lowest possible SOC. A good technique is to speed up if there is excess range near the end, the last 1/3-1/4th distance, or slow down if too little.

Bob Wilson

 

I've been modeling it using my SR+M3 and it remains a very competitive time. One reason for a West-to-East trip in November is the beginning of the high wind season in California. They wanted the extra boost to get over the Rockies. It is a route favorable to a tail wind. To preserve every Watt, they drove without cabin heat and near as I can tell, no seat heating too.

I've got a speculative route, East-to-West, the original Cannonball direction with optimized charger stations.

My thinking is use the Thanksgiving or Christmas holidays to do a practice drive East-to-West; rest up in California, and; a return for record drive West-to-East. Advertise for a second driver in the East coast, engineering schools:

1. Pass a math test based upon my SR+M3 metrics.
2. Lighter weight to minimize rolling drag.
3. Family or friends to stay with in California before the return trip.
4. No pay but expenses on the trip.

During the trip, the back of the Tesla will be equipped as a sleeper. There will also be a cooler for beverages and 'finger food' and a hot-water thermos and electric heater used during the taper charge segments. There will also be a camper, port-a-potty for emergency, road side service. Both of us will have carry-on with spare clothes, toiletries, snacks, and electronics.

Bob Wilson