Charging Efficiency Mobile Charger?

[jmichaels]

I took delivery of MY w 20" wheels last week. Been using Mobile Charger (as supplied w/car) with NEMA 14-30 adapter (that the plug available in my garage). I am very surprised that my charging efficiency as reported by Teslafi is 97%+ over 16 charges, both long ones and short ones. Seems too good to be true. I am disappointed about missing my expectations on total range (316), but the charging efficiency is now the bright spot in my learnings so far. Am i missing something on charging efficiency? What are you guys seeing?

 

[Zoomit]

TeslaFi charging efficiency numbers have been all over the place for me. I stopped paying attention to them years ago.

 

[jerry33]

I don't use Teslafi, but because it gets the numbers from the car, you only get the efficiency between the on-board charger and the battery (97% sounds about right for this). Wall to battery can only be determined by a metre.

 

[MY-Y]

When charging at 11 kw, even a 1% loss at the HPWC would make it quite warm after a while. It should be quite close to 100%.

 

[Rocky_H]

They have always been about mid to high 90's %. Yeah, it's nice to see that it's pretty good.

 

[empiredown]

It's a Connector, not a Charger... It's just delivering energy, not producing it. There SHOULD be very minimal loss, and that is mostly due to heat, resistance, etc. Your car is doing all the work with the energy you are delivering it and THAT is where the loss occurs and where you should be concerned. As has been stated, you can only really determine that if you track how much energy you have delivered to the car and what it has actually done with it. Good luck!

SS

 

[jmichaels]

Yes, Connector not Charger...oops...sorry about that. Found an interesting thread on this topic at Tesla Forum...basically saying that when charging at 240/24A (my level with NEMA 14-30), efficiency from the breaker panel to the battery was tested to be 93.9%. So the 97% ish I reported above (Teslafi number) means (theoretically) 3% is lost between on board charger and battery and another 3% lost from panel to the onboard charger....6% ish total loss. Make sense? Agree w/my numbers?

Here's the post i referenced: 120V/240V Charging Efficiency - Answers! | Tesla

 

[empiredown]

Only way to tell for sure is to get your data and do the math. Using the figures in the post is great for comparison, but ultimately it’s what you can do with your own stuff that matters.

Personally, I’d be fine with those numbers given the imperfect environments and equipment we are using. That sorta loss is a rounding error for many things.

Good luck!

ß