Battery degradation is the reason people give for not buying an electric car.
It deserves a real answer with real numbers, including the parts that are still unknown.
Odometer 20,953.8 miPer mile 10.9¢Degradation 0%On FSD 97.4%Snapshot 2026-09-05, baked at deploy. This page makes no live requests.
Measured degradation
0%
Usable capacity reads 79 kWh against an original
79 kWh at 104 cycles. TezLab rates the pack
excellent and puts both degradation and cycle count in the low band for comparable
cars in the region.
One reading is not a trend
Zero percent at 20,954 miles is a real measurement, and it is also
a single point. TezLab returns no capacity history for this car yet.
So the timeline is being built here instead, one reading every Monday.
Twelve of them make a story. This is reading number one.
79kWh
Usable capacity
104
Battery cycles
96/100
Recurrent Range Score
281Wh/mi
Real consumption
Range lost while parked
Phantom drain is the cost of owning the car on days you do not drive it. Over
12 days this pack gave up 109 miles of
range sitting still, an average of about
9 miles a day.
08/25
Miles85.8 mi
Drives4
On FSD82.9%
Efficiency101%
Idle loss22.7 mi
Chargedno charge that day
measured. The spikes are days the car sat outside in Tennessee summer heat with
cabin protection running. At 38.7¢ a kWh and
281 Wh a mile, 109 miles of lost
range is roughly
$11.82
of electricity. modeled, because the drain is measured in range and converted to dollars here.
Warranty, the good news
The battery and drive unit are covered to 2032 or 120,000 miles,
whichever comes first, with a floor of 70% capacity retention. At 104 cycles and
0% measured loss, that floor is a long way off. The basic vehicle
warranty runs to 2028 or 50,000 miles.
Not here yet
TezLab returns null. Built locally from one reading per Monday. Once there are enough Monday
readings to plot, the chart replaces this note.
measured invoice or sensormodeled derived, and says soPulled 2026-09-05 · VIN serial masked · no addresses
