Wireless charging

It's all future stuff, but I thought some people here might be interested in an interview I had with a major company working on wireless charging systems here in the UK. It's not likely to be incorporated into this current generation of electric cars, but it does provide a fascinating glimpse of what we might see in the future.

They've been testing the system in New Zealand and trials start in the United Kingdom with bus charging systems next year: The Future for Electric Car charging?

How efficient is it (compared to conductive charging) ?

They were claiming around 95% efficiency in tests, although I notice they've now downgraded that to 'over 90%'. Which is still pretty efficient.

Mike, +1 for marketing.

The [primary] EVSE that's been in use in the US since the 1990s is inductive. Nissan has also been testing an inductive unit in their cars. It's detailed in their briefing documents. See:

October 2009 Page 48

AndyH said:

The EVSE that's been in use in the US since the 1990s is inductive. Nissan has also been testing an inductive unit in their cars. It's detailed in their briefing documents.

Click to expand...

Not sure how you can say that ! Both conductive (Avcon based on older J1772 standard, by the way) and inductive (SPI or LPI (Small & Large Paddle Inductive), like MagneCharge) have been in use since the 1990s. And ... for example, since Tesla & MiniE are conductive, they can and frequently use (with adapters) the Avcons (not SPI). If you had said ... "One of the EVSE's that's been in use ..."

But thanks for that Nissan link ...

LEAFer - glad you like the Nissan link. The rest of the docs are in the Media portion of the forum under 'reference docs'.

Sloppy - thanks. The Tesla and MiniE didn't exist in the 1990s, so I conveniently ignored them. The EVSE for the EV1, GM S10, and RAV4 was/is inductive.

The Ranger used the earlier J1772 square connector.

I stand by the original intent - which is to remind our friend from across the pond (and EV noobs) that there's nothing new about inductive connections and that inductive was the primary method used by the 90s era vehicles.

Ok, Andy, ... your original intent is good! And I didn't mean to sound too harsh ... sorry if I came across that way. Honda EVplus also used the Avcons, as did many DIY conversions, many of which are still using them today. Conductive is inherently more efficient that inductive. But if 90%-95% can be achieved (needs to be demonstrated unquestionably) that would be the kicker ... when added to the obvious advantages of inductive (no direct contact needed, safety, possibly useful for in-motion, etc).

And I wanted to mention the history of the J1772 with the Avcons. (Those EVSEs are great candidates to be converted in their existing locations to J1772-2009.)

I worked on an inductive charging system with handheld computers in the early 1990s: you'd put your handheld computer in a cradle and it charged up inductively.

It was horrendously inefficient - 15-20% at best, but that was before we invented global warming, so that was okay. I can easily see how the efficiency could be improved to around 60-70% easily enough, but I really can't understand how they can get 90-95% efficiency.

Seems like an awful lot of infrastructure would be needed, and the coils would need to be near the surface, which would complicate maintenance and revisions.

If it did work, this would present some problems also. One of the attractive elements of EVs to me is that they can take advantage of off-peak electrical generation -- energy (or at least generating capacity) that's currently wasted. Inductive road charging would invert this -- you'd be charging fleets of electric vehicles during the afternoon rush hour -- the worst possible time.

The path forward for EVs, imho, is increasing range to where daytime charging is something only rarely needed. How often would you need a daytime charge if the range were 400 miles? 600 miles? Maybe I'm overly optimistic but I think we'll get there before we have tens of thousands of miles of electrified roadways. And manufacturers aren't going to want to build-in inductive charging until there is infrastructure to support it, so we're talking about quite a long ramp-up to get such a system to work.

Inductive charging is nice at parking places - no need to connect anything. But I suspect this will remain a niche even when it gets commercialized.

Our challenge as a society is to do simple things in large numbers (i.e. scale up) - rather than doing cool things in small numbers.