Am I calculating my battery capacity correctly?

[Michman]

First, I want to say I’m a fairly new Tesla MS owner (4 months) and am still learning. These forums have been SOOO incredibly helpful. - Thank you!

I bought a certified pre-owned 2016 MS 75D. I know it’s not realistic to expect to have exactly 75kw of battery capacity after 5 years. So, I’m trying to figure out exactly how much capacity I have for long trips.

Lately, I’ve been doing the following math (figures from the consumption screen);
Wh/mi x projected range / remaining battery percentage

I figure the Wh/mi times projected range should give me my remaining Watts in the battery. Divide that by the remaining percentage should give me the Watts remaining when full.

I do this calculation a lot, under all kinds of circumstances and drives. I almost always get around 70,000 Watts. Seems to make sense that my 75D would have lost a little over 5 years and now I can only get 70kw now.

So for me, that means planning trips to 65kw to leave a small buffer.

Does this seem right? Thoughts?

 

[Bmac]

There might be an easy test for you to determine how much capacity has been lost to age. On your home charger, charge to 100% to determine what the projected mileage range is. If I'm not mistaken, when new your car probably could achieve 257 miles projected range (that was my initial range at purchase).

for example, as mentioned my car could achieve 257 miles when new. Today, when charged to 100% I am lucky if I get 238 miles.

 

[jmmmmm]

My 2016 75D is at about 95% of original rated battery/range/capacity.
243 miles projected
~71kW @ 100% charge

 

[beatle]

Note that the actual projected range is not accurate even at the rated consumption levels by the consumption graph. You need to hit a lower wh/mi target than the benchmark set in the graph.

For example, the consumption graph specifies 310wh/mi as the benchmark to reach rated range, but I actually need to get 292wh/mi to get rated range.

For planning trips, abetterrouteplanner is useful.