Solar Proof of Concept

[calmingaura]

Does anyone know if it is possible to directly charge an eGolf from a solar panel system through direct wiring not through the charging port? One reason is I want to minimize inverter loss if I charge from my home 48V solar panel system. Another reason I want to know is that I want to place two 100W solar panels on the eGolf and trickle charge the eGolf Lithium Ion batteries.

I know that two 100W solar panels on the roof of the eGolf will only provide enough power to add 2-5 miles of range per day, but that is actually how much I drive on average daily. I also want to do this as a proof of concept, that an EV NEVER has to be plugged in and can still serve as a reasonable form of transportation.

I have added solar panels to the roof of another car and used it to trickle charge the 12V battery and power a 24V fridge. I know I can use the solar panels to charge a separate battery to power an inverter that can be connected a Clipper Creek power supply to charge the car, but that is mightily inefficient and inconvenient.

Does anyone have any knowledge or experience on this? Thanks!

 

[eGolfJoe]

The pack is 410V fully charged and around 300V discharged. You'll need to go through some kind of inverter to boost the voltage up high enough. You're not going to be able to get to the individual lithium cells without a lot of work and voiding your warranty, not to mention you'll have to come up with your own battery management system to even be able to do that safely.

Panels are so cheap. It'll be easier for you to add more panels to make up for conversion inefficiency.

 

[JoulesThief]

Look at 24V 240 to 300 + watt solar panels. Each panel in that size is good for 1 to 1.2 to 1.3 amps at 240V. 10 to 15 or more panels should get you 12 to 20 amps at 240V, 3.6 to maybe 5 kWh charging rate. You can add inverters per panel as you add panels.

You generally do need to be hooked up on the grid with the inverters to keep all of them in synch at their 60 hz cycle, so that they even work together.

You are going to have to charge through the charge port, or void your warranty.

 

[GdB]

How about this?

Get enough small PV panels that add up to between 300 and 400V in series. Direct connect to the DCFC port with some sort of arduino controller.

It may need a relay that shuts off the PV direct DC when charging of driving.

 

[Sparklebeard]

How about this?

Get enough small PV panels that add up to between 300 and 400V in series. Direct connect to the DCFC port with some sort of arduino controller.

It may need a relay that shuts off the PV direct DC when charging of driving.

If you're trying to DCFC, you will need to connect a charger between the panels and the DCFC inlet. I am unsure how simple it would be to try to fake the charge management and handshaking with an Arduino. You can't just push 400V onto the DC cables. And it would most absolutely destroy the drivetrain and battery warranties!

Assuming you don't also mean to have a CCS handle permanently plugged into the charge inlet since that would not allow the car to drive!

 

[GdB]

True but keep in mind the cables could be pretty thin, being very low current, 1 to 3 Amps.

The real enabler could be the new super thin flexible metal backed PV panels, if small enough versions exist, they can curve to fit the large curvature on most cars.