Devil's Advocate - Charge it to 100%

[MXWing]

Does Tesla state clearly anywhere what the routine (daily) maximum charge should be?

Elon Musk says anything up to 90% is fine.

My friend who is a battery engineer says between 20%-80% SOC is optimal.

I'm trusting my friend on this.

 

[willow_hiller]

Does Tesla state clearly anywhere what the routine (daily) maximum charge should be?

I could have sworn it recommended 90% in the Owner's manual, but no where to be found... https://www.tesla.com/content/dam/tesla/Ownership/Own/Model 3 Owners Manual.pdf

As with many things Tesla, Elon's tweets are a good source of (authoritative?) information Elon Musk on Twitter

 

[Hank101]

IMHO, it seems that his response should be viewed in context to the question asked, and not interpreted as a general practice guideline.

 

[willow_hiller]

IMHO, it seems that his response should be viewed in context to the question asked, and not interpreted as a general practice guideline.

Alright, here's another tweet when asked about nightly charging practices: Elon Musk on Twitter

 

[StealthP3D]

If you actually charged to 100%, you'd spend most of your driving in the 70% to 90% range... essentially maximizing the vehicles performance at all times.

You are not thinking clearly here. At any given moment during your drive cycle, the difference in the state of charge between charging to 90% and charging to 100% is less than 10%. It's less than 10% because charging to 100% misses out on some regen charging. And the effect on the acceleration of 10% less state of charge is not significant unless perhaps you are at the local drag strip racing another Tesla with 10% more SOC. Most people wouldn't even notice the small hit to peak power caused by 10% or less reduction in SOC.

On the other hand, the disadvantages are significant:

Shorter battery life
Reduction in regen/less consistent driving experience
Longer charge times
Less efficient charging (the batteries accept charge much easier in the middle of their SOC).

In other words, the only reason to charge past 90% is if you plan to draw it down to 20% or lower (or you are at a race track with electronic timing devices). Those who have short daily commutes can charge to 80% to maximize longevity and efficiency with no detectable hit to performance. At the track? Charge it up and get every last ounce of performance.