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Inductivly Charging an 8.4V lithium ion Battery.


Dec 8, 2009
Dec 8, 2009

I am a new one to the site. Am just expolring my options at the start of a project. I have to charge an 8.4 V battery inductivly. I have looked on the datasheet and it needs 1.4 A and 8.4 to charge. so i'm assuming that i need to get around 13W of power.

My plan is to:

I can use a DC power supply to switch my AC mains supply to DC at around 30V and 1 - 2 A

Create a high frequency switching circuit on the primary side to change the 50 hz main supply upto around 50 Khz (or would resonant frequency be better?)

I am planning on using two ferrite cores one on the pirmary and one as the seconday. I have not decided on how many turns to use on each as of yet.

Transfer the energy over an airgap between 5mm and 15mm

On the secondary side i will have to rectify the power to supply a smoth DC supply to the battery.

I am constrained by the size of the seconday coil in size as it can be no larger than 2.5 CM in height and diamter.

The primary side is not restricted in size.

Do you think it will be possible to transfer this amount of power inductivly? And does anyone have any advice they can give me to help me on my way?