I don't know how this one works - if the interface works well then just changing the Pilot duty cycle will allow the charger to tell the car how much it is allowed to pull and when the solar panel delivers less, the charger should simply shut down to avoid keeping the car "on" and actually depleting the battery instead of charging it. Some time ago I read about some experiment that EMW (Electric Motor Werks) did on I believe a Tesla charging from a Juicebox where they turned the pilot signal down to only 3A charge current at 110 I believe that the result was that the charger provided about as much power as the car consumed between keeping computers running, fans or battery heaters and other peripherals, so net-net, there was almost no change in charge after a full night plugged in, but at least it demonstrated that the Juicebox could successfully convince a car to draw extremely little power.
Side story here: I have a "Solar Battery Bank" which is a device with several Lithium cells in parallel inside, a micro USB plug to charge them up and 2 USB master plugs (A-type) to supply power to charge a phone or tablet. I have several of them and they generally work (although Ebay capacity claims are often 10x overrated) but this one also has a solar panel that can charge its internal battery. Indeed, as soon as there is decent ambient light, the processor inside sees the output from the solar panel and starts blinking the built-in LEDs to indicate that it is charging, just like when you plug its micro-USB into a wall adapter or computer. I was afraid that the blinking LEDs would draw more current than the built-in (small) solar panel provides so I opened it to measure. Turns out the LEDs are high efficient ones and draw only about 1-2 mA However, the processor is not low power and when it is on, it also turns on the DC/DC converter that boosts the 3.7V Lithium output to a stable 5V for the USB ports. Between processor and boost converter, 60mA is consumed out of the battery. The solar cell in full sunlight delivers a max current of 150mA. So, while it is theoretically possible to recharge the battery using the solar panel, any decent period that sun light is not optimally hitting the panel will result in a *dis* charging of the battery. Solution is simple, of course: disconnect the solar panel and wire it through a blocking Schottky diode directly to the battery, so the processor does not see the output from the panel and not activate. To avoid overcharging the battery eventually, a 150mA bypass regulator at 4.2V will do the trick, making the solar charger usable. Back to solar charging an EV: In downtown Sunnyvale is a solar-powered charger near the train station on Evelyn, at the other side of Mathilda. The power is coming from a bank of south-angled solar panels, charging a battery in an enclosure under the panels. That battery then runs a stand-alone inverter, connected to the adjacent charging station. If the light on the charging station is on, it receives power from the inverter. Once the battery is depleted, the charger turns off. I do not know the story behind the solar charger and why it is not simply powered from the grid, but there must be a reason/opportunity that has likely faded into the past by this time. Two years ago the charger was not working so several complaints were sent to the city, who deferred it to the person responsible and eventually it was fixed, probably a new battery needed to be installed. However, the charger that was presented here, will not have a battery, so all I can think is that it is a solar panel and inverter, coupled to a charging station (which is only a GFCI and contactor and pilot signal generator) that can modulate the power draw from the EV to the amount of power available from the panel and gracefully shut down when the power is lower than the Pilot can go. (Simplest way is to remove the pilot signal which will cause the EV to stop taking power) Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: EV [mailto:[email protected]] On Behalf Of Alan Arrison via EV Sent: Thursday, June 16, 2016 7:38 PM To: [email protected] Subject: Re: [EVDL] Level 1 charging solar What happens when clouds come by and randomly block the sun? Do the inverters start up and shut down gracefully? What does the car do when it sees the AC power going on and off? Sounds like a recipe for damaged electronics. Al On 6/16/2016 3:27 PM, Seth Rothenberg via EV wrote: > Friends, > > I saw a video of someone charging a Nissan Leaf > (presumably) using the provided Level 1 charger > and flexible solar panels attached to the car. > (presumably with an off-grid inverter). > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
