Here is why you should turn the charge rate down on your Tesla!

Today I discuss the reasons I believe it is best to charge your Tesla a little slower, rather than faster......

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[robertgamble]

Hello, a 30 amp breaker should only use 24 amps continuously. Continuous power on any breaker is 80% of the breaker power rating.

[cliffm]

TESLA will tell you this and that, as they want your business again after some years.

The perfect way is to keep you BATTERY CHARGE BETWEEN 30% - 70%, and charge it to 90% - 100% when you’re going for a long Road Trip, period.

(I own Tesla S & X, and I’m an Electrical Engineer)

[jonhemperley]

Actually my model 3 popped a notification while charging at home stating that charge rate was being reduced due to overheating of the circuit wiring. Never thought of reducing charge rate. Thank you!

[pepstein]

It sounds like your EVSE is installed incorrectly. It shouldn't be allowed to pull more than 80% of the circuit breaker rating (and that rating should not exceed the maximum allowed for the type and gauge of wire used). Set up correctly, you shouldn't be able to increase the Amps setting in your Tesla above that 80% figure (the + button will turn gray). For the Mobile Connector the adapter specifies how much current to allow. For wall mounted hard wired EVSEs there should be dip switches or similar to limit allowed current.

[MrTheexplorer]

Other thing to keep in mind is the car draws around 200-250w additional when powered on to charge. (BMS, inverter, mcu, etc) So 20-25A 240v is a great sweet spot But charging at say 6A will use more power from keeping the car powered up.

[robchiste]

I installed a 50 amp circuit with 3 conductor #6 wire. It can handle 32 continuous amps while charging. Most new breakers will trip when current goes over 80% of rated load. You are very lucky your house didn't burn down.

[lagardenz]

Very helpful...we just lowered charge rate from 48A to 22A so we can use only solar power, at 48A we had to pull about 8kW from Grid. Now 100% solar. Thanks for the tip and explanation.

[MHODL]

As soon as you said 30amp breaker I was like woah wtf 😂 glad you lowered it on your car.

[JeanPierreWhite]

Reflecting on the title of the video I think it would be more accurate to say this is why Matt had to reduce his charge rate (and for good reason). Not sure this applies to the Tesla community at large as the title suggests.

[Garrison]

Charging at lower current is not more efficient. While the wires and the connector plug may run cooler, they are supplying current for a longer time, resulting in the same energy loss.
But if you don't need to charge quickly, lowering the current is a good idea. Perhaps there is less stress on the charger in the car and the battery.

[GregHassler]

Your EVSE should be setup to advertise to the car a max charge rate of 24 amps (80% of your 30 amp circuit). If it's not doing that your EVSE is improperly configured for your circuit. Your car should only adjust *downward* from the max advertised by the pilot signal of the EVSE, it won’t allow you to go higher than the pilot.

What brand/model EVSE do you have?

[Edit] This will also fix it for your other vehicles, they won't pull more than 24 amps either once you get the pilot signal set correctly.

[TigerInTheWoods]

I have 3 Tesla - 2 MY LR and M3 RWD. We installed Nema 14-50 adapter w/ 50Amp CB and 8/3 wire (about 20 ft. line from the panel). There's always a resistance when charging whether short or long charging cable. We set up our apps to 28A limit charge 50-80% when charging one at the time. Departure/Precondition 30 mins. before Charge. Also don't forget to precondition before departure to max range and efficiency. if you can afford a Tesla EV, installing the proper materials it's immaterial.

[aussieuGA]

I used to ask about lowering charging rate for longevity and the consensus was it was only there for RV parks and unique situations. They seemed to think that if you plugged in and “scheduled your departure”, Tesla may see you have 10 hours before it’s needed and throttle down the charge rate automatically. But the car still keeps the rate high, leaving the group discussions feeling the max amperage is still well below the increased wear threshold. I too still think lower may be better if you’re keeping the car for many years.

[treborg]

I was following Tesla's recommendation to always charge when at home, and I now have about 10% degradation in range on a 94K mile MX. My vehicle also will not charge to 100%, currently now to 97%. I have stopped charging every night, and now only charge when the HV battery falls below 30% and charge to 80% max. I've been charging at 25 A for some time.

[relaxationsounds]

I set my charge rate at 80% of what the breaker is set. So my 60 amp 220v breaker allows me to run at 48A. However I will turn mine down to 30 to 35amp to do my research and check temp at the 48 compared to 30 or 35. Also will see how long it charges to 80% what I charge up to every few days. Check for any difference in range as well.

[samg]

Been charging like this for a while also. Less heat, more efficient, amd bette for battery. Also, you want to keep it charging longer if it's sitting out in the cold so the battery stays warm until you use it. If it stops charging, the battery has time to get cold again.

[jimmyvole]

Your setup didn’t meet the code requirements… it needs to be 20%, more than the max of your car charge speed, so you need 40A breaker & wiring for your 32A mobile charger. Keep it down or you will BURN your house

[freetrailerpoor]

If you set it to lowest amps say 6, note the voltage. Say it is 240. If you bump it up to 30 amps and voltage is 225 you lost 15 volts in heat. Which is about 6% loss.

[shawnl]

That's not how current (Amperage) works. Current will not increase with resistive losses since the Tesla charge rate is current limited and not power limited. 30A in one end of the wire is 30A out the other end.

Also keep in mind that (disregarding line losses), the faster your level 2 charge, the more efficient it will be since there is a base energy consumption overhead for the coolant pump, relays, etc. of around 300 to 400 Watts. So for example, that means 240V @ 30A will be 1.8% more efficient from the wall than 240V @ 24A.

[laloajuria]

so you had a 30A breaker....and you were pulling 34A .... so lowering it to 25A was better for everything?