Charging your EV Decoder Ring

You would think there would be an easy FAQ if you have an Electric Vehicle, turns out that after navigating through all the many sites, here are the easy steps, if you aren’t lucky enough have the plug and play Tesla.

First the plug nightmare

As usual with the start of an industry there are way too many “standards” for plugs, so nothing really plugs into anything without a little thought. Here’s a map:

Level 1. This means good old 120V with the familiar US two prong (technically called a NEMA 5. This will take a long time, if you have a monster 60KWH battery on a Chevy Bolt for instance, it will take days to charge since you can do 120V x 20 x 75% Amps = 1.8Kw/Hour but you can’t drive a circuit at 100% and there are losses, so assume 25% buffer from max amperage to usable. Every car has an onboard AC to DC converter at 2.4, 6kW or even 7.2KW, so the speed of charging depends on it. It’s maximum is 1.9Kw

Level 2. This is the 220-240V and of course is much faster, however, there are no less than three different plugs. There is J1772, NEMA 14-50 and then Tesla’s proprietary plugs. The NEMA 14-50 is used by newer Tesla’s and i3s the same as what you find in an RV Park. It is four prongs with one L so you can’t misinsert it. There is also an older Tesla proprietary connector. The J1772 is the North American standard and is five prongs and is used by early Volt and Leaf’s in the so. This runs at 16A or 30A which corresponds to a 20A or 40A circuit (you need 25% buffer when you are charging continuously). This mathematically means 3.5Kw or 7.7Kw charge. When you use this, you can either have 16Amp or 30 Amp effective charge. Most cars have smaller chargers, so the Leaf is 2.4KW internal charger. But this is way faster, so with the 7.2KW charger in the Bolt, you can use the full 30 amps at 240V (30×240=7.2KW). This means that a flat battery gets charge in 60KWH/7.2KW = 9 hours.

Level 3. This is the 440V but done as a DC, that’s because the AC/DC converter is huge. There are quite a few variants for level 3. There are three important ones, the CCS is a J1772 with DC below (technically called J1772-2009). It is what is used by American and European manufacturers (Audi, BMW, Daimler, Ford, General Motors, Porsche, Volvo and Volkswagen). Then the Japanese have CHAdeMO and Tesla has an adapter for it as well in addition to their own proprietary Supercharger.

How to charge at home, beware the bad extension cord

Well of course Tesla has their own proprietary Superchargers and plugs, I won’t cover that here, but if you have some other company, there is J-1772 plug (this is a huge 5 prong monster) that you plug into the car. There are three levels:

You get a J-1772 to NEMA 5 for  120 V plug for home. This you use to plug into your car. The car has an onboard charger, so it just sense voltage and starts drawing. This is going to be slow, for a 60KWh battery, charging at 1.8Kw/Hour will take 34 hours to get to a full charge, but it is useful for trickle charging. One important gotcha is that the connection to the extension cord has to be good. The first time I did this, we used an old cord and they have a sensor box, it would just stop charging after a while without an error. And would report “Charge Complete”. I don’t know why anyone thinks quitting after five minutes is charge complete. So make sure you get a good extension cord.

Level 2 charging box means you have a J-1772 to 240V for home (or CHAdeMO if you have a Japanese car).  Now if you want to do this at home, you either need to buy a $500 box and install it,

Level 2 converter cable. If you are lucky and have a 240V circuit in your garage for a dryer (yippee), then you don’t need to do this. Dryers use a 4-prong plug called NEMA14-30 so here are the adapters that are around

  • QuickPower J-1772 to NEMA 6-20R. (As does AV)  For $99, you get a connector to a three prong.
  • They also sell for $20 adapter to connect to NEMA 14-50P (used in RV parks rated to 50A). Apparently you can modify the NEMA14-50P to work with the NEMA 14-30 if you have some pliers or use this Tesla based guide to figure out all those 240V connectors (there are an incredible number). So basically look at what you have and there should be some way to hook it up
  • There are also adapters for  NEMA 10-30P which the older three prong version of the NEMA 14-30.
  • A direct J-1772 to NEMA 14-30, If you have a 30 amp circuit then and ClipperCreek LCS-30P will get the most charge out for you for $515. It will take out 24 amps from a 30 amp circuit so gives you 24A x 240 V = 5.8Kw chargeThere is also the ClipperCreek LCS-25P available for $500 (I don’t know why so much) and it supports 20 Amps actual charge from a 30 Amp circuit breaker. So this is 240V x 20 = 4.8kW. So a 60kWH battery will take twelve hours to charge. In their world P means that it is portable and doesn’t need to be hardwired.
  • Since there is only a $500 choice of a cable, you can also look at an adapter which goes from a 30 amp NEMA 14-30P to a NEMA 14-50P but if you do this you have to make sure the car doesn’t draw 50Amps when this is for a 30 amp circuit otherwise you trip the breaker or worse!

Sign up for a charging network, get the RFID cards!

Some car companies have partnerships with charging networks. For instance Nissan has six months free for Chargepoint. Basically each network has their own chargers and you there are a variety of plans:

  • Chargepoint. This is sort of an aggregation network. Their underlying chargers are priced by the individual installations. Some are free, like lots of Universities. There is also a complex set of individual promotions, but these are not geographically sorted, but at least we can all get free charging at one Whole Foods in Florida, you spend a lot of time clicking on promos. But basically, you get an application and there is also a card that you get. Some companies like Chevrolet give you an RFID card. You also want to download the mobile application and make sure your credit card is attached to it. Also make sure to map the stations near you. They do tell you want is charging and what is free which is nice. One important thing that you have to have is a ChargePoint RFID card. Free chargers sometimes are not provisioned for visa, etc., so if you try to use Apple Pay, it seems like it works, but then the charge later fails.
  • Blink. This is another network. They are mapped by Chargepoint but have their own scheme. There is yet another card for you to buy. They charge a la cart.
  • AVnetwork runs the West Coast charging network although it’s really Oregon and a little bit of Washington and the great thing is that these are fast DC chargers at 24kW to 60kW. They have single use fee of $10/charge or a monthly  subscription for $20/month to use them, so you have better be running up and down the coast a lot.

Know where the charging stations are. There are relatively few so know where they are and what they take. The ones near universities can be great. Some cars are great like the Leaf of i3 about finding stations, others like the Bolt have no support at all.