Ok, I need to use four lithium-ion polymer battery cells to power a
5vdc load. I have access to the smbus interface (for battery charge % and auto-shutdown) and roughly 2*10 cm worth of board space.I have a dc input jack on board, input can be anywhere from 5 to 24vdc and is rated for around 8a (iirc).
the load will be about 50w at the max, around 15 under normal conditions. the output must be 5vdc +/- 3%
about 1cm above the pcb, I have a heat sink capable of dissipating a reasonable amount of heat.
I need to have the dc input charge the battery as needed, and power the load a swell. I also need the load to be powered by the batteries when the input is not plugged in (with a seamless change from battery to dc and vice versa), and I need to know the charge of the battery.
help (this is going on a custom pcb for a school project)?