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Saturday, February 13, 2016

Tesla Model 3 vs Chevy Bolt - Charging Network tips the scales

Tesla and GM are both coming out with ~$30,000 electric vehicles with ~200-mile range. How do these two compare?

Today, we don't know the specs in detail or the final pricing so it is impossible to make an objective comparison. However, one thing we do know though is the charging network support.

When people talk about cars, they generally talk about things like acceleration, cargo space, styling and the like. While these things certainly matter, today I'm going to be discussing charging. Other than asking "How long does it take?", charging is often overlooked by first-time EV buyers.

Fast charging matters

Most EV charging happens at home or at work. Level 2 public charging is nice to have, but cars don't tend to spend a significant amount of time at shopping centers or restaurants, so Level 2 charging, while nice for an opportunistic sip, is not convenient for road trips. Long distance driving requires DC fast charging. Depending on the car and its range, fast charging can add more than a hundred miles of range in less than 30 minutes. This is not as fast as a gas station fill up (yet), but it certainly makes long distant trips possible. This greatly increases the utility of an electric vehicle, even if it is only needed occasionally.

Tesla Model  vs Chevy Bolt :: battle to be EV of the future 

Assuming the Model 3 and Bolt are similar in price and specifications, they'll be in direct competition and their differences will be far more important than their similarities.

This coming clash of monster EVs reminds me of a stop-motion monster fight I saw in a movie as a kid. Bear with me, this really does tie back to our topic. I think there are lessons in that old movie battle that might apply to the battle for the EV of the future.

 Griffin vs Cyclops Centaur
In the movie, The Golden Voyage of Sinbad, a griffin and a centaur are locked in battle. They are evenly matched, it's a stalemate. One of them fights for Sinbad, while the other fights for the bad guy, Sorcerer Koura. Earlier in the movie, The Oracle of All Knowledge said, "For it is the deeds of weak and mortal men that may tip the scales one way or the other." Koura figures out that this battle is what the oracle's prophecy referred to; so (spoiler alert) he slashes at the griffin when it's distracted by the centaur. One small cut from a human on a giant monster would normally not matter much, but in this case, it was all that was needed to tip the scales. The griffin's weakened leg slips, the centaur gets the upper hand and the battle is quickly over.

This lesson has stuck with me. The little things matter and can often be the deciding factor for big issues. In our EV battle, the charging network could be the "deeds of weak and mortal men that tips the scales."

Too Many Standards Means No Standard

"The nice thing about standards is that you have so many to choose from." ~Andy Tanenbaum

Today, there are three options for DC fast charging. They are CHAdeMO, CCS, and Tesla Supercharging.

Japanese and S. Korean automakers (Nissan, Mitsu, Kia) use CHAdeMO. European and US automakers (GM, Ford, BMW, VW) use CCS. Whereas Tesla, of course, has their own proprietary (open patent) system.

There are plenty of comparisons out there that have details of the charging rate for each. For the purposes of this discussion, they are fast enough for treks and that is fast enough.

SAE Combo Charging System (CCS)

GM supports the CCS DC Fast Charge standard. This is the standard defined by the Society of Automotive Engineers (SAE), the same organization that defines the Level 2 standard that is used worldwide. Despite great engineering from a trusted engineering standards body, CCS has a few problems.
SAE CCS Plug and Receptacle 
First, CCS was the last of the three DC methods to be deployed. This generation of EV started selling in December of 2010 with the Leaf and Volt. CCS did not start deploying in any significant amount until 2015. This is 4 wasted years.

Second, as you can see the CCS locations in the map below, CCS stations are not spread throughout the country. You could not drive coast-to-coast using CCS stations. The stations are clumped in the areas where the cars are sold.

There is no central body examining the CCS network to determine where they are needed. About a year ago BMW, Volkswagen, and ChargePoint teamed up to deploy CCS stations. They seem to be focused on the coasts. This makes sense since that is where the cars sell the best. But that does not mean those are the only places that owners want to drive.

SAE CCS DC Fast Charger Locations Feb 2016 via Plugshare

Third, I'm concerned about how well the CCS stations will be maintained. Today, the Blink CHAdeMO stations have a horrible reliability record. The stations are installed at stores and restaurants that know little if anything about them. And they are often even unaware when they are not functioning, let alone how to repair them. Additionally, at these stations, there is often only one DC fast charger at a given site. That means when it breaks down, you're out of luck. What you had planned as a 30-minute quick charge stop could turn into a 4 hour Level 2 charging stop.

Tesla Supercharger Network 

Tesla was unhappy with the fast charge options offered by either CHAdeMO or CCS, so they created their own. Unfortunately, this added yet another method and complicates charging matters. Tesla superchargers use the same connector for either AC charging or DC supercharging. 

Below is a map of the Tesla Supercharger network that is active today.

Tesla Supercharger US Network Feb 2016 via Tesla Motors
As you can see there are multiple routes that you could take on a coast to coast drive with this network. And as you'll see below, before the Model 3 comes out, the network will be even more complete.

Tesla Supercharger US Network Planned By End Of 2016 via Tesla Motors

Tesla's locations are selected to allow for intercity travel. Station locations are more likely to be in between cities than in an urban center. This allows it to be used by traffic in either direction.

At a supercharger location, there are generally multiple stations. This means that if one station is broken or occupied, there are other stations that you can use.

This supercharger network is just a part of Tesla's charging infrastructure available to their cars. There's also destination charging that allows you to fill up overnight at many hotels and BnB locations.

Tesla's stations are free and they are part of the Tesla ownership experience. This helps them sell cars. This means that the stations are well maintained. The stations are internet connected and the state of each station can be queried. If supercharger stations are down, it reflects poorly on Tesla's brand and quality. It is in their best interest to keep these stations up and running. They respond quickly.

The final advantage that Tesla has is that their cars can use any the three DC fast chargers. Tesla has an adapter for CHAdeMO stations and they are making an adapter for CCS stations.

Wrap Up

The Tesla Model 3 has several advantages over the Chevy Bolt.

First, Tesla has taken an active role in creating a maintaining a vast, free charging network. GM, on the other hand, seems to think that, just as with gas cars, refueling is not part of their business.

Second, reliability is incredibly important in a charging network. When you plan a route and expect recharging to be there, it had better be there, available and functional. Tesla's stations are maintained by Tesla, they have skin in the game. The network is there to help them sell cars. Other networks are deployed by companies that are trying to make a profit from charging fees. For them, if 95% of their network is operational, they are still generating 95% of their revenue.

Third, the ability for Tesla vehicles to use adapters is a significant advantage. CHAdeMO equipped vehicles can only use the CHAdeMO network. CCS-equipped vehicles, like the Bolt, can only use the CCS network. Tesla vehicles will be able to use both of these networks and the Tesla Superchargers. This makes Tesla's vehicles the easiest to find charging for compared to any other.

If the oracle from Sinbad was referring to charging networks, then the scales are tipped in Tesla's favor.

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