Charging your EV

iOK, it takes forever, but I finally have the complete decoder ring for what you need to charge most EVs at home.

TL;dr

If you have a Bolt EV

  • In stall a NEMA 14-50R plug (these are $8 parts, but you want an electrician since you will need a 50 amp circuit breaker). While you can get the Clipper Creek HCS-50P, it is nearly $600 and isn’t portable but the Maxx-40 is $400 and is portable. This will give you a 40 amp circuit at up to 9kW charging although the Bolt will only pull 7.2kW, but you might as well get something for bigger cars in the future since the prices are the same.
  • If you already have a NEMA 14-30R Plug. While you can get a separate stand, it is way easier to buy a “portable charger” on Amazon, these are about $500 and it gives you a NEMA 14-30R plug on one side and then a JEDEC J1772 plug for the car. This gives you a 30 amp circuit breaker, so it can handle 24 amps sustained. The Clipper Creek LCS-30 is $500 from Amazon. The Clipper Creek folks have a particularly easy numbering scheme L means it is portable and H means it is hard wired station, then the last number is max amperage.

If you have a Tesla

  • Install the 14-50R plug and the Tesla has the charger built in so you don’t need to pay anything extra, this gets you 9kW charging, the thing actually supports 11kW, but there doesn’t seem to be an easy way to get this installed in a home.
  • You can also get a dedicated 72 amp charging with a dedicated box from Tesla for $500, this isn’t a bad deal if you really need lots of charging at home, but make sure to order your Tesla with the optional “big charger. Practically speaking, most folks will probably just do the 14-50R.

If you have both a Tesla and a Bolt or something else

  • Get a pair of 14-50R plug and the Maxx-40, then you can charge the Tesla from the Maxx-40 since it has a J1772 to Tesla convertor or if you need them both, you can connect the Tesla directly to one plug and use the Maxx-40 for the other car.

It is complicated because there are so many different manufacturers, but here’s how to think about it:

  1. You want a Level 2 charger at home, this is way better than the 120V charger you get with say a Bolt EV. The math here is pretty clear from Clipper Creek, but basically every car has it’s own internal charger that has a maximum, you can see it on the list but the Bolt EV for instance has a maximum of 7.2KW (what they call the acceptance rate) and the Tesla X is a whopping 11.5 or 17.5 if you have the upgraded internal charger. As an aside you can check this and look at the Chevy standard charger that they market which is a 32 amp box. As an aside.
  2. If you go to commercial setups like a Tesla Supercharger or what is called a CCS (combined charing system), you can do lots more. The Bolt for instance can handle 55kW. This is a common installation, it is 440V (wow!) at 125 Amps. If you do the math with a 60kWH battery that means you can theoretically charge from empty in an hour or so! The level 2 chargers typically run at 6kW (
  3. If you are just running around town, then you can also plug into a 120V outlet and there is a setting on the Bolt (which I never remember to set) for 8 amps or 12 amps, that is 960watts or 1.4kW. It is decent for trickle charging.
  4. Installing a circuit. What does that mean in practice, well divide by 240 Volts to get the maximum amperage a car can accept. With the Bolt EV that is 7.2kW/240=31 Amps and for the Tesla X regular that is 11.5/240=48 amps. Note that this is what is called sustained amperage, so you need something that is higher at the circuit box. For instance a 32 amp sustained needs a 40 amp circuit break and a 48 amps needs more like 60 amps so you need to install a direct connect circuit since they don’t make a plug like this. If you get the fast package, you can charge at 72 amps (!!!) but you need an 80 amp circuit and it is direct wired to the charger. It is also Tesla only, so you can’t use with other cars.
  5. If you are lucky you may already have a dryer circuit in your garage already and there are sea of plug standards, but the two common ones are 14-50R, this means type NEMA type 14 (a standards body), carrying 50 amp maximum (so it supports 40 amps continuous) and R means a Receptable (e.g. the outlet). The other common one is called the NEMA 14-30R, this is 30 amps and has a different plug so you don’t accidentally put one into the other.