Charging numbers

If you’re like me, you like your numbers, you like to understand them, at some point you like to look at them and make some sense out of them, your numbers. Me? I like that. Not for the sake of the numbers by themselves, but for what they might tell you, and with that, to let you better decide and opt in your decision making. You might call it life, deciding I mean.

Around these parts, Lisbon and surroundings, there isn’t much choice of charging: we have been promised superchargers from as early as 2014 –  to be fair they said it would be working around 2015… Right. Not yet. Now July 2016 is the promised land, sorry, date. Let’s hope for the best. Meanwhile life goes on and charging the 85 kWh battery of the “thing” poses some challenges.

For daily commute, conventional charging is more than OK. You have your 230 V grid voltage (with luck you have 240+ish V and that gives you a bit more juice) and an overnight charge of 7 hours at the traditional 16 A gives you a confortable (18 km/h × 7 h) km = 126 km for next day driving.

What if you do want to drive more than your regular commute? Other means of charge have to be found. Like Fast Charging or your local version of destination charging. That’s where you have to be open minded and creative.

Fast Charging: locally this is the name for the CHAdeMO chargers, the PCR, “Ponto de Carga Rápida”, or on a fast translation, Fast Charging Point, 50 kW stations that can charge up to 252 km/h. Not bad.

Your local version of destination charging: it depends heavily on what your destination has or authorizes you to connect to.

Next I’m addressing the “standard” wall plug installations (not the public charging points or others). The km/h charging rates described come from the fact that I normally have available above the stsndard 230 V value, your “milage” may vary. So, resuming, the “standard” wall plugs can be one of these 4:

  1. The traditional monophase 16 A 230 V, and if you’re lucky it will let you use the 16 A; but most conventional places aren’t prepared for that much Ampere being used in max permanently and that means 13 A real world use, to be on the safe side. Safe being the definitive keyword, remark my words. The plugs can be the traditional Shuko or the small three pin blue plug, this one is safer and enables the full 16 A use, depending on your wires cross section. This gives you between 14 (@12 or 13 A) to 18 km (@16 A) of usable range for each hour of charging.
  2. An industrial or more advanced (Amps wise) place may offer the possibility of monophase 230 V and 32 A. This is normally implemented with the large blue plug. Never saw anyplace with it and yet the large blue plug is used by well versed Electric Vehicle users/owners: it’s the way you can squeeze the most out of a traditional monophase instalation. Suppose you know the place safely delivers up to 30 Amps. With the blue plug you set your A current needs yourself, you have to know that the wires and the circuit breaker also safely permit what you are set to draw. In my region Tesla has the blue 32 A adapter sold as an option, you have to ask for it, pay 90 € (as of this date) and better know up to what Amps you can get from where you connect it. This gives you aprox. up to 34 km (@32 A) of usable range for each hour of charging.
  3. Some places, garages, public installations, provide free use of three phase 16 A 400 V power, the small 5 pin red connector. This is good: it normally gives you 11 kW of power when all three phases are able to deliver the said 16 A. Real life teaches you something else. I’ve seen places where the said 16 A drop drastically to 6 A or less, places where instead of a steady current flow it varies along time from 5 to 16 A, and places where you can squeeze up to 18 A from the three phases with no problems, very neat. It depends heavily, from my experience, on the quality of service and power delivery of the contracted power company and the quality of the wiring in the different places. Normally, and luckily, the car takes care of these variations by itself. If a place seems unsafe for 16 A 400 V, the car automatically drops it to a steady 12 A, or less. As a consequence your km/h charge drops heavily. As a rule of thumb, when connecting in these places, I wait a few seconds, up to a minute, until the charging stabilizes. If the monophase voltage value the car is showing, the V value affected by a (3) number to show it is three phase, is switching between 218 and 220 V while using 16 A, it is almost certain the car will drop the Ampere current to 12 A, this way guaranteeing the V to go up to stabilize above 220 V. This affects your km/h charge. What do I do manually to avoid this? Instead of 16 A I set the Amps to 15 A and wait for the V to stabilize. If it stays above 220 V you have a serious bet that the circuits will hold and the car does not drop the current to 12 A. The difference is moving from the theoretical 11 kW to the car’s decided 8.3 kW (12 A) or to your decided 10.3 kW (15 A). The km/h charge rate varies between 55 km/h (never saw this), ~40 km/h and ~50 km/h, respectively. You are happier when you charge at ~50+ km/h.
  4. There are places where you can have 32 A 400 V. This is implemented using the large 5 pin red plug for 22 kW. In theory you can get up to 110 km/h charged range. The most I saw was ~107+ km/h. This is good. This is very good. I hope this was the norm. I know I charged three times with this big red 5 pin connector. Every place should have this configuration available.

For the 1, 2 and 3 descriptions you can rely on Tesla provided charger: in Europe – at least for my country – the Tesla charger is delivered with home 16 A (usable 13 A) schuko connector (description 1) and also the small red pin connector, the three phase 16 A 400 V (description 3) for up to 11 kW charging. For description 2 you have to ask the large blue connector, payed separately.

To use the 22 kW of the big 5 pin red connector you have to buy, or build, an extra charger.

So, welcome to the real world. You have to love it. I know I do love it.

Disclaimer: I know a bit or two bits, pun intended, on A and V, trying to learn a bit more on A and V power use. All info is provided “as is”, use it at your own personal risk and pleasure.

Female plugs, five pins three phase 32 A (22 kW) and three pins single phase 32 A (7.3 kW).

My numbers. I do between 80 km and 120 km per day. I rarely charge at 16 A. My installation enables up to 22 A. For 7 h of night charge I can get

  1. @ 16 A, 7 × 18 = 126 km
  2. @ 18 A, 7 × 20 = 140 km
  3. @ 20 A, 7 × 22 = 154 km
  4. @ 22 A, 7 × 24 = 168 km

I normally charge @ 18 or 20 A. More than enough. If for any reason a full charge is needed, a Sunday 24 h charge gives you between 24×18= 432 km and 24×24= 576 km. Enough, I say.


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