When towing a trailer/RV with an electric car there is a general ‘rule’ that you should expect the range to decrease while towing by roughly 50%. The reality is the range while towing could be effected more or potentially less depending on lots of factors such as going up lots of hills etc. However, the main point being for this post you should expect a significant range decrease while towing with an electric car. Therefore, how fast a particular electric tow car can put energy back into the battery is very important.
Introduction To Electric Tow Car Maximum Charge Rates
Below I’ve included a table of electric tow cars/trucks and their maximum towing capacity and maximum charge rates. The links for each car/truck go to the specific article I’ve written about them. Now, it is important to note that not all versions of a particular tow car have the maximum charge rate stated. The figure I’ve given is the highest for that particular model.
The Audi E-Tron is an example, the E-Tron 50 has a maximum charge rate of 120kW while all other E-Tron 55 models charge at up to 155kW. The point being, different maximum charge rates on different specs of a car/truck is something you need to be aware of.
|Electric Tow Car||Max Towing Capacity||Max Charge Rate|
|Rivian R1T||11,000 Lbs||300 kW*|
|Rivian R1S||7,700 Lbs||300kW*|
|Tesla Cybertruck||14,000 Lbs||250 kW +|
|Tesla Model X||5,000 Lbs||250 kW|
|Tesla Model Y||3,500 Lbs||250 kW|
|Audi E-Tron||4,000 Lbs||155 kW|
|Polestar 2||2,000 Lbs||150 kW|
|Volvo XC40 Recharge||3,300 Lbs||150 kW|
|Bolinger B1 & B2||7,500 Lbs||100 – 150kW|
|Nissan Ariya||1,500 Lbs||130 kW|
|VW ID.4||2,700 Lbs||125 kW|
I’ll do my best to keep the table above up to date. However, please check out my electric tow car/truck list which I will be updating with new vehicles/models. You will probably note, there are certain models on my electric tow car list which I’ve not included into the table above (yet). For instance, while its highly likely the Hummer EV will be rated to tow, as of yet GMC has not given the truck an official towing capacity.
Old (Used) vs New Electric Tow Cars – Differences In Charge Rates
Above I stated how there are differences between the maximum charge rates with the same model of electric tow car depending on the specific spec/trim level. Well, if you are considering purchasing a second-hand electric tow car you should also appreciate that some older versions of an electric car may have a slower maximum charging rate. As the technology in electric cars is changing pretty rapidly, year on year there are generally improvements being made.
So let’s look at an example such as the Tesla Model X, while current versions can take advantage of the latest Tesla V3 Superchargers which charge at up to 250 kW, that’s not the case for all the second-hand versions on the market. For instance, the first Model X versions from 2015 have a maximum charge rate of 120 kW. Even if you plug that car into a V3 Supercharger it will not be able to charger faster than 120 kW due to the hardware limitations of the car itself.
Important: Electric Car Rapid Charging Rates Are Not Linear
So the table above on charge rates shows us the maximum capabilities of each electric tow car. However, its very important to note that no electric car (currently) will achieve its maximum charge rate consistently. Let’s presume the car is plugged into a charging station capable of meeting the cars maximum charge rate. Even then no electric car based on current lithium battery technology will maintain its maximum charge rate for the duration of the charging session.
Therefore, there is a term you will hear more over the coming years, an electric cars ‘charging curve’. Basically, at a certain battery capacity, a car will typically be able to take a certain amount of charge somewhere up to the car’s maximum charging speed. Different cars from different manufacturers have different charging curves. This is due to the differences in battery chemistry, capacity, hardware and software.
Different Charge Curve Profiles
Some electric cars have a bell curve charging profile where the charging speed starts low at a low battery state of charge. The charge rate peaks around a 50% battery state of charge and then tapers away as the battery gets closer to being fully charged, around 80%. Other electric cars have a flatter charge curve. Potentially with a flatter charging curve even though the maxium rate of charge is lower the total charging time can be shorter due to a higher average charging speed over the length of the charging session.
I cannot currently provide a charging curve profile for each specific electric tow car as much as I would like to. Though, in the future, once this information is available I will be referencing it here. However, what I can reference is an excellent video from electric car YouTuber Bjørn Nyland which illustrates the charging curve differences between different electric cars rather well.
The video above shows how in terms of charging speed the Audi E-Tron actually performs very well compared to the competition. Hence, while the E-Tron is not a very efficient electric car, it does have the benefit of getting charge back into the battery quickly. In the future, I hope to have more pieces of content such as this to illustrate the difference in real-world charging speeds between different cars.
The key takeaway from the above is the following. The maximum charge rate of an electric car is not a maintainable charging speed over the duration of the charging session. Hence, potentially a car with a lower peak charging speed which can maintain a higher average charging speed may be able to top up its battery more quickly.
Some Rapid Chargers Are More Rapid Than Others
This article is about the hardware within the electric car/truck in terms of its maximum charging rate. However, to be able to take advantage of a cars maximum rate of charge it needs to be plugged into a rapid charger which can provide sufficient power. Rapid chargers start from 50kW and currently go up to 350kW. There are many different rapid charger network operators around the US with different prices and payment options. I’ll be writing a Guide to Rapid/Fast Charging An Electric Tow Car/Truck soon.
Conclusions On The Fastest Charging Electric Tow Cars/Trucks
So when it comes to determining which electric tow car can charge the fastest while its maximum speed of charge in kW will provide a good indication, it can not be used as the definitive answer. I’m very hopeful that going forward more data/testing will be available for each electric tow car demonstrating their charging curves under specific scenarios. For instance, just as an electric cars efficiency can be impacted by cold weather conditions, so can its charging speed. Hence, its why Tesla and Mercedes pre-heat their battery packs before the car reaches the rapid charging station so the car can accept the fastest rate of charge possible. I expect more manufacturers to be implementing this feature going forward.
Its also worth noting as a general rule, electric cars charge the fastest when the battery state of charge is between 10% and 80%. There are reasons for this which I’ll get into in later articles. The general point being, as the rate of charge decreases considerable charging from 80% to 100%, its generally not worth doing so. However, that also means with less than 100% in the battery the cars full range is not available. Which when towing as the range is effectively cut in half due to factors such as aerodynamic drag having less than 100% charge may be a significant consideration to factor into planning your journey.