Inductive Battery Charging

Hello everyone,

i would like to supply my Arduino with a Battery. But I want to Recharge it with an Inductive System. Does anyone has experience with that? Are there matching systems/products on the Market anywhere?

Thank you and have a nice Day Kelevra86

Several electric toothbrush manufacturers use an inductive charge system so you might be able to salvage components from an old set.

I know, but I don´t need that tiny amount of current. 200mA or more would be fine.

In addition I have to charge it with an "air-distance" of ~4cm between primary and secondary coil.

By ~7-8V

Kelevra86: I know, but I don´t need that tiny amount of current. 200mA or more would be fine.

In addition I have to charge it with an "air-distance" of ~4cm between primary and secondary coil.

I suspect that needing/wanting a 200ma charge rate and 4cm of distance between the coils using air as the magnetic coupling media is going to take very large coils and probably not practical. There is a reason most power transformers of nearly any wattage use a ferrous metal as the magnetic coupling media. Air is pretty inefficient for transferring power.

200mA at 7V = 1.4 Watts

That sounds high for inductive charging. You might want to look into the Powermat to see what kind of power it can transfer: http://www.chipworks.com/en/technical-competitive-analysis/resources/recent-teardowns/2011/10/inside-the-powermat-wireless-charging-system/

Also, this instructable might be useful, especially page 6: http://www.instructables.com/id/Wireless-Power-Transmission-Over-Short-Distances-U/step6/Data/

It'll give you a good idea of how large of a wire and coils you would need for milliwatt performance...