Tuesday, October 19, 2021


RVelectricity: Could the self-charging Sion EV be your next toad?

Dear Readers,
As I dive further into my GoGreenRV study on the future of EV and hybrid-powered RVs, the question of EV toads becomes important. After all, if your towed vehicle (“toad”) had a range of even a 100 miles or so, and never had to be refilled with gasoline, wouldn’t that be great?

But where do you charge your toad? Can you power it from your TV (tow vehicle) trailer connector? Or how about letting the EV toad motor charge its own batteries while you tow it wheels down? And will campgrounds welcome a toad being plugged into an unused outlet on your campsite pedestal without making you pay extra for it? These are all great questions without definitive answers right now.

Future Shock

Now, I’m not sure of all the details yet, but Sono Motors is introducing (and taking pre-orders for) their new Sion EV. It looks like a traditional EV except for the paint job.

But what makes this EV unique is that it’s covered with 248 solar panels that allow it to recharge directly from the sun without being plugged into anything!

Say whaaaaaaaaaat?

Yup… If the promotional literature is correct, this EV will recharge itself while sitting in the sun, adding an average of 10 to 20 miles of battery range per day (70 to 150 miles per week).

While that doesn’t sound like a lot of miles per day, consider that its main battery capacity has been upgraded to 54 kWH with an expected range of 200 miles or so WITHOUT the sun. For many of you that don’t drive a lot around home, getting 150 miles of range per week from the sun (for free) could be pretty sweet.

Can the Sion EV also be plugged in to charge?

Yes, it will accept a fast charge to bring the batteries up to 80% SOC (State of Charge) in 30 minutes, or can use a standard Level-1 or Level-2 charger to recharge overnight when plugged into a 20-amp or 50-amp receptacle. Read more on their website.

Can it be towed wheels down?

This RVer brings along a car plus bicycles.

I don’t know, but I intend to find out. If so, and there’s an easy way to set it up for towing, this could arrive at the campground fully charged.

This should be a software change since most all functions in an EV are drive-by-wire. I don’t know if any of these EV manufacturers are aware of it, but I’m doing my best to let them know about it.

What about regenerative brake charging?

Again, I don’t know, but I’m going to ask. While I don’t think that any current EV technology is set up to use its motor/generator to continuously recharge the EV battery while towing, I’m trying to find out if it can be used as an exhaust brake (exhaust toad?) to apply its own regenerative braking to charge its batteries when you’re going down a long grade, or even stopping at an intersection. Rather than throwing away all that kinetic energy as heat in your brake pads, perhaps it could add a bit of charge to the EV toad batteries each time.

Where to find out more about the Sion EV…

OK, that’s all I know for now. But if this works, then an EV toad could be practical. Take a look at Sono’s website, and I’ll include more information as I get it on my GoGreenRV channel and group. Read more HERE.

Let’s play safe out there….

Mike Sokol is an electrical and professional sound expert with 50+ years in the industry. His excellent book RV Electrical Safety is available at Amazon.com. For more info on Mike’s qualifications as an electrical expert, click here.

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3 months ago

There is a video on Youtube showing someone towing his Tesla with his Mercedes at 70 mph to recharge his battery. It takes him quite a distance to get over 50% charge, and implies that the Mercedes transmission may have been struggling to tow the Tesla. What it showed me was that some people have too much money to waste on what could be an expensive curiosity. Anyway, if this one does work that way, what a great toad. Maybe a regenerative system that can be switched for distance towing with less drag.

3 months ago

“Wearing” the solar panels seems unnecessary for the small return… I know people who use their home solar array to charge an EV but that is incredibly inefficient due to double conversion DC>AC>DC… Have you ever seen somebody deliberately set up a goodsize freestanding solar array to charge their EV directly DC-to-DC?

Mike Sokol
3 months ago
Reply to  Wolfe

We also need to consider the transmission losses in the electrical grid between the power plant and your electric meter. There are no simple answers to efficient energy generation, transmission and storage. http://insideenergy.org/2015/11/06/lost-in-transmission-how-much-electricity-disappears-between-a-power-plant-and-your-plug/

3 months ago

Could the principle of regenerative braking be applied to moving down the road as a toad? It seems like even at 10% charge over 100 miles it might amount to quite a bit and it would be basically free.

3 months ago
Reply to  bjensen6

Well – maybe cheap. Regenerative braking while being towed will put more load on the tow vehicle – wear and tear as well as fuel. I think that’s why Mike was talking about getting the toad integrated into the brake system. IE: it only regenerativly charges when you are braking or going down a long hill as part of the decent control systems.

Mike Sokol
3 months ago
Reply to  Kyle

That’s correct. I envision the EV regenerative braking system would only be engaged while the tow vehicle was braking.