A thought on charging efficiancy

[phillcom3]

Disregarding if you need a long trip every day what's more efficient. Charging every day 10 15 20 percent to 80 or letting the car get down to 30 percent and charging back to 80.
So charging a little every day Puting a minimum percent in(probably not geting up to temp etc) or one large charge twice a week?

My thoughts are if it's at peak efficiency afyer 20 mins or so isn't it more effective to get to that and hold it for a long time say 3 4 hours vs the 1.5 I am seeing doing a 60 to 80 every day.

 

[Saghost]

The only time I think it matters is when the pack isn’t near the best temperature range for charging. In those cases, you’d only have to heat the pack once for your once a week charge, vs heating it every day.

 

[Roy W.]

Disregarding if you need a long trip every day what's more efficient. Charging every day 10 15 20 percent to 80 or letting the car get down to 30 percent and charging back to 80.
So charging a little every day Puting a minimum percent in(probably not geting up to temp etc) or one large charge twice a week?

My thoughts are if it's at peak efficiency afyer 20 mins or so isn't it more effective to get to that and hold it for a long time say 3 4 hours vs the 1.5 I am seeing doing a 60 to 80 every day.

My money would be on the 30-80%

 

[Watts_Up]

Theoretically, the best efficiency will be to have the maximum SoC (battery charged at the highest value) :

- The higher the % charging value, the higher the voltage, so the lower the current will be for a given power needed to move the car.
- The lower is the current, the lower are the resistivity losses (P = R * I^2)

Just to give an idea, if the battery voltage is about 400 V, and on full acceleration you get 400 kW of power, the current is 1,000 Amp.

If the battery is low and only has 350 V (just a guess), you need about 1,150 Amp. So in my example,
if you have 1 Ohm resistivity losses, for this extra 150 Amp, the extra Power loss is 22,500 W.

About efficiency, independently of the SoC, I think the charging process (converting 220 V AC into 400 DC)
is the less efficient part. Then the phantom drain (keeping your battery warm) is the second major losses component.

If you want to minimize the losses when you are parked, turn Sentry and Alarm off, and also Summon off (from the AutoPilot menu)
I get about 3% losses phantom drain a week when I don't use my car.

If you are very curious about power consumption, I would recommend getting an OBDII plug and use the App Scan MY Tesla.

 

[MrBadger]

They are talking about SOC % rather than power limit