How do i control the EV charger in the Nissan Leaf?

[cupoftea]

Hi,
I am charging my electric car purely and only from an inverter (output is 240VAC sine) which runs off my wind turbine.
My electric car is a Nissan Leaf. Sometimes the wind will be low, and there will only be some 200W or so coming from the inverter....but the Nissan Leaf charger runs at maximum power all the time (3.2kW) .....how do i get the Nissan leaf charger to be "patient" and just simply charge its batteries with whatever power level comes off the wind turbine/inverter?
ie, how can i communicate with and control the charger in the Nissan Leaf?

 

[BradtheRad]

Somewhere the charger has a low input resistance. I guess that's what makes it 'impatient'? The inverter cannot maintain its output at a usable voltage.

Surface thinking suggests a series resistor between inverter and charger. However that robs efficiency. It's not a solution.

Or, a device which imposes a 10 percent duty cycle, storing 200 W from the charger during 90 percent of a cycle, then sending a brief 2000 W burst to the charger.

 

[betwixt]

The critical factor is how much power your turbine can produce. If its output is low, the chances are the inverter will never run anyway. How is it all connected, your optimal solution would be to use the wind turbine to produce DC for your inverter, possibly with a battery bank for extra storage, and the inverter to be grid tied to incoming line AC. That way you benefit most from the turbine even if the Leaf isn't on charge.

Most grid-tied inverters have a data port that let you read their current input and output powers, you should be able to use it to produce your own disconnect circuit that breaks the AC to the charger when the output is below a threshold.

Brian.

 

[cupoftea]

Thanks to both of you for interesting points. And also, you confirm to me that an electric car charger in an electric car cannot be controlled......its its own boss.....it charges batteries at max power, and thats it.......so someone with a 200W AC supply cannot charge their Nissan Leaf battery (or any other electric car for that matter).

 

[betwixt]

More likely the charge controller in the battery decides how much it can take, much as in mobile phones and laptops. If the charger itself was 'boss' it would only work with specific car models.

I can't confirm that, my car is a hybrid so I can see the battery state and whether it is charging or discharging but it has no external connections to the battery itself.

Brian.

 

[FvM]

Modern on-board chargers have control features to set the charging power. You should check with the manual.

 

[cupoftea]

Modern on-board chargers have control features to set the charging power. You should check with the manual.

Thanks, ive been looking for manuals on the www but cant find them. I am pretty sure that no device outside the car can control the charge rate (ie set a maximum for it). Obviously, as Betwixt kindly says, ultimately the charge rate is set by the car looking at the start of the charge of the battery.

Though i would like to know if theres any way of telling the on board charger to charge at say, a maximum rate of 200W?

 

[FvM]

As far as I'm aware of, Nissan Leaf exposes a Typ 2 AC charging connector including a pilot signal (CP contact). An intelligent Wallbox (EVSE) can use it for energy management purposes, e.g. limit the charging power. According to IEC 61851-1, the smallest input current that can be set through CP is 6A. Means you need to stop charging if the available power is lower than e.g. 1.5 kW.