Magnetic Saturation

[Young]

Which leaves us wondering - if they do away with reductive, do they need to put a big coil somewhere else in the vehicle for the new charger circuit?
Is there another charger technology that they could use that doesn't require a big inductor?

I do not know any other way than using a heavy inductor. Unless there is some inefficiency in using the motor winding as inductor, I do not see why they want to carry around a heavy component.

 

[TEG]

I do not see why they want to carry around a heavy component.

Apparently they can do it a bit more efficiently without using the motor windings. Also, they don't have to pay a royalty if they avoid 'reductive'.

 

[JRP3]

The efficiency gain may be more financial than electrical :wink:

 

[WarpedOne]

That and that heavy component is not that heavy really, about 10 kg or 20 pounds.
Half a percent of total car weight. If it's losses are 10% lower that means 2 kWh less heat during charging and 2 kWh less on electricity bill at each charging (according to roadster charging, 50kWh full charge, 20kWh of heat.

 

[Young]

That and that heavy component is not that heavy really, about 10 kg or 20 pounds.
Half a percent of total car weight. If it's losses are 10% lower that means 2 kWh less heat during charging and 2 kWh less on electricity bill at each charging (according to roadster charging, 50kWh full charge, 20kWh of heat.

RAV4-EV 5kw charger weights about 60lb. Tesla charger which should handle higher power will not be significantly lighter.

 

[WarpedOne]

That's the whole charger, we are talking about stator windings.

IRC Tesla's whole motor weighs around 80 pounds, its stator just cannot weigh much about 20 pounds, there are also a heavy copper rotor, bearings, frame etc.

 

[TEG]

The reductive charging royalty must be steep if it turns out to cost less to include so much redundant hardware instead.