Any benefit in reducing charge rate?

[tonyb99]

My level 2 charger will run at 30amps, but I could run at 15 or less and still get a full charge overnight. Any benefit in doing so?

 

[Sparrow]

Never hurts to charge somewhat slower. Heat of all components over time can be a killer. That being said all your charging equipment is probably rated at 40amps or more so you probably are not stressing them at 30amps. So we are only talking about the breaker and wiring.

 

[SucreTease]

The answer is, yes. Resistive heating (known as I²R "I-squared-R") loss rates are reduced by the square of the current. Cut the current in half, and the loss rate is reduced by a factor of 4. However, because you have to charge twice as long, this means that the total reduction in heating losses goes down by a factor of 2. That means that total resistive heating losses goes down linearly with current.

 

[Rocky_H]

Everything in the car can handle much higher charging levels than that, so the car absolutely won't care. So it's really just about your wall connector charging station. It's built to go at a maximum 30A, so it may be kind of warm at that level, and it can help some to turn the amps down a little bit just to keep it cooler and save some heat cycling.

 

[frankvb]

Considering there is a fixed power draw during charging (at least not changing much depending on the charging rate) consumption e.g. to power the vehicle while it's charging, it's probably more efficient to charge faster. Resistive losses in cabling are almost certainly smaller than that (think of a few hundred W needed to just keep the car's systems running).

 

[SucreTease]

Actual data: Ideal Charge Rate??

 

[tomagucci]

there are some examples of people supercharging their car all the time with the batteries degradation in line with expectations (basically it is fine). ill charge as fast as I I can as often as I need, figure the batteries will be the last issue on my car (I'll give it up before the batteries fail me)

 

[slmitchell737]

How long do you plan on keeping your car? Now that I’ve traded M3 to a model Y and eating two new car depreciations, I’m hoping to drive this one 8-10 years or so

there are some examples of people supercharging their car all the time with the batteries degradation in line with expectations (basically it is fine). ill charge as fast as I I can as often as I need, figure the batteries will be the last issue on my car (I'll give it up before the batteries fail me)

 

[tomagucci]

I’m currently planning to use it till it stops working for my needs. Maybe 5-8 years minimum.

 

[user212_nr]

My level 2 charger will run at 30amps, but I could run at 15 or less and still get a full charge overnight. Any benefit in doing so?

No. Supercharging is 150-250 kW, and you are charging at about 7 kW with the 30A plug. So you are charging at 2% of the capacity, do you think there is an advantage at 1%? It does not work out to a lot of power when you divide by the 1,000+ individual battery cells.

There is actually negative effects for the lower rate, such as the battery getting colder in winter climates, and the computer using additional energy while it is on longer.