How to Create a Laptop Charging Circuit?
I'm building a laptop, and currently I have 18 NCR18650B lithium ion cells. I was going to use an external battery pack, but the PCB was way too big. I just ordered "18X 2A single 18650 Li-ion battery cell protection circuit board PCB assembly" for the batteries and "Generic 19V 9.5A 180W AC Adapter For ASUS G55 G55V G55VW Power Supply Cord PSU" for the wall. The motherboard runs off 19V, and can be powered with a 2 pin Molex connector. Could someone please provide a schematic that would work as a laptop charger, preferably that could use those parts?
It needs to be able to charge the lithium ion cells and at the same time provide 19V of power to the motherboard through the molex connector when plugged in, and when unplugged, immediately switch from charging the batteries to using them to power the motherboard, without a noticeable drop in power. It would be even better if it could interface with the computer through usb 2.0/1.1 or a serial/COM port to show battery health. Something that can be made with a small/low form factor would also be preferable. Specific IC's would be very helpful. Thanks!