aspalmer
Newbie level 1
I have a device which runs off of two 3.6v Li-ion batteries in series. I need to charge the device off of usb. Since 2x3.6v is bigger than 5v for usb, I need to switch them to parallel before charging.
I have IC's selected for charging them in parallel. I just need help figuring out how to automatically switch them from series to parallel when usb is plugged in.
My initial idea is to just use 3 pnp transistors that disconnects the batteries from each other and both of them from my load circuit, when usb is connected. Would that work? I am worried about shorting.
I have IC's selected for charging them in parallel. I just need help figuring out how to automatically switch them from series to parallel when usb is plugged in.
My initial idea is to just use 3 pnp transistors that disconnects the batteries from each other and both of them from my load circuit, when usb is connected. Would that work? I am worried about shorting.
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