A friend showed me this a couple weeks ago on his electric car, so I got one and just installed it on mine. It's a gizmo that monitors the AC power input to the charger, so you can easily look at the power consumed during charging. It includes a remote monitor display that connects wirelessly to volts/amps pickup units on the vehicle. This lets you keep the display unit in the house while wirelessly receiving data from the car.
The unit is made by efergy, and is really meant for monitoring electricity usage at a house level. It's meant to be installed inside the service panel where electricity comes into the house.
However, in an electric vehicle, whether it's a car or motorcycle or scooter or bicycle, there is a spot in the charging circuit just before the charger where you can measure AC power going into the charger. This is where you install the data telemetry unit.
This is the unit where electricity goes into the charger on my car. It's a pair of NEMA 14-50 sockets and plugs, as well as a 5-20 socket because I do need to plug in a couple normal gizmos while the car is charging. For plugging into various power outlets I might find, I have a variety of adapter cords to convert from 14-50 to other kinds of outlets.
This is the box .. nice box
These are all the components of the system.
Note the AA batteries. I'd rather have these units plug into AC outlets to power themselves rather than having yet another gizmo in which to keep AA batteries installed. Sigh.
These are the sensors to detect AC voltage and current. They clip onto the power cable and then connect to another box that transmits data.
This is the sensors attached to the two hot lines on the power system.
AA batteries installed
The transmitter unit connected to the sensors.
There's a simple dance to get the two units (the transmitter and display panel) paired with each other. Once paired the display panel shows kilowatts of power detected by the sensors.
It also shows the $$ cost of that power - once you've configured it with the cost/kilowatt-hour.
It also shows the carbon footprint of that power - once you've configured it with the carbon impact of your electricity. I wonder how you find that number out.
It also shows kilowatt-hour consumption per day. This isn't ideal, for an electric car owner, because you'd really want kilowatt-hour consumption per charge session.
You do have to configure the unit with the voltage, and I believe this sort of sensor can only detect amperage and not voltage. It means that - if you only charge your vehicle on one voltage then the display unit will always show the correct kilowatts. If you charge at different voltages at different times, you'll have to adjust the display unit settings. I usually charge my car at 240 volts but sometimes at 120 volts depending on the power available wherever I go.
Installation was pretty simple and the unit - so far - seems simple to use while providing useful data.
I believe this could be installed on a commercially built manufactured electric car. You'd simply have to locate the J1772 port and identify which wires coming out of that socket correspond to the two AC hot wires. With luck those wires will be available to clip on the sensor units.
This is pretty close to what I have been dreaming about lately, as I am constantly in the basement to check if my Thunder's charger and BMS allowed the extracted charge of the day to be completely replaced (I have a dedicated kWh-meter on the charging outlet - in the basement where the cable leaves the house). By chance and the bad efficieny of my charger pretty exactly the Ah's used divided by 10 is the kWh's that should go in from the grid, so that bit is pretty simple. But it would be heaps easier to monitor with such a gizmo, from my office chair up in our flat.
Fore some reason still unknown by me charging usually stops prematurely when the battery temp. is below about 5°C. The BMS I have already instructed, if it HAD an external temp. sensor in the battery (which it doesn't), to only reduce charge current if the temp. dropped below -20°C, because I make sure anyway that I charge with the battery at above freezing temperatures or in any case while it is still chemically active right after arriving home.
But the incomplete charging still happens from time to time, so I need to check what went in.
The downside of that gizmo is that it is pretty complex to implement, even worse than a Cycle Analyst, the additional batteries it needs (as you already mentioned), the additional electomagnetic "smog" due to the transmitter - and my reduced physical excercise during the fall and winter months while running up and down the two stories between flat and basement :-)
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
Installation is SIMPLE. David was pretty thorough, however it is fundamentally just wrapping the sensors around the wires. After that, you turn run through the setup steps and change to match your voltage and local electric rates. Much easier than programming a VCR or TV. It is designed for monitoring a hole house, so it seems like overkill for just a car, but it runs remarkably well with the small loads.
I have been running mine for a little over a month. If you buy one, please contact efergy and ask them about an option for displaying amps. I contacted them about it and was told several people had brought it up before. If enough people request it, then they might consider implementing it. Very nice people to work with.
Installation is really simple, just clip the sensor(s) around your power lead(s). Setup is trivial. For me, the majority of the time was stripping the insulation off the power cable so I could attach the sensors.
The unit does not read amps, so contact efergy and lobby for it.
As Charlie said, it's pretty simple to install. Just clip the units to the wires, connect them to the transmitter, then set up the display unit. I probably went overboard in the details.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
I think it was that insulation stripping that was getting me worried most...
But at any rate this thing will be too bulky for my semi-maxiscooter. I already have two timers and a kill-a-watt-type gizmo in my underseat compartment that already take away about 1/3rd of the space in there.
Anyway, thanks for this info!!!
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
The display unit is wireless. You can just leave it on your desk. Hide the transmitter next to the sensors. You do not strip the insulation from the current carrying conductors, only from the outer jacked so you can separate the conductors, as they are measured separately. This unit would only measure current from the AC line going into the charger. It doesn't measure any of the motor or battery current. Mostly for tracking the cost of energy and how much you are putting in. For 120 volts, you only need one sensor installed.
I would think that more than one sensor is only necessary for three-phase AC-Power. When I dug through Efergy's website yesterday there was NEVER talk of having to splice phases out of cables and wrap multiple sensors around the phases individually, there is only ONE sensor that needs to be clipped around the AC power cable to be sensed. Maybe they updated their products in the mean time to do away with the necessity to splice to the individual phases?
I am more worried about the sensor and transmitter that would have to reside in my scooter (and require space), on the input side of my charger. The receiver unit of course is the thing you take with you to wherever you want to remotely monitor grid power usage and still are within the transmitter's range.
As I already have an individual meter in the basement for my charging monitoring I might be better off with replacing that meter with a transmitter and adding a receiver here in our flat. I hardly ever oportunity charge, so that would be a viable solution for me.
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
There is only one sensor
In your switch board you have access to the Live and Neutral wires separately.
In the Ac cord that goes to your bike, there are 3 wires - Live, Neutral and ground.
you want the sensor to be around either the live or the neutral, but not both.
If the sensor is around both, the fields cancel each other out.
That's why you have to cut away the first layer on insulation - to separate out the live and neutral
The Efergy is designed to be put into a switch board - that's why they don't talk about it
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
Thanks for the explanation, Matt!
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW