After looking at doing a switch mode power supply i had a thoght, why not just use a simple PC power supply thats already nice and efficent and has a low ripple voltage and good surge capabilities

at the moment i am hitting my head on the desk because of this, if only i thogt to do it that way in the first place.

anyway down to bussiness, it looks like the project will be split in to 4 parts, input, output, power storage and processing.

input is fairly easy and can mostly be controlled in software (its bassically a whole lot of on/off switches), this allows for solar, the PSU and everything else, expected input is 12V and mabey 3.3 + 5 as well (see outputs) nice and simple and includes monitering to dutect when the power has failed

processing does all the calculating for the switching as well as handels user input (buttons, ssh, web) because as much of the control algorithims are in the Main CPU and not the PIC it allows you to swap out policies and charging algorithms as you wish allowing you to swap an SLA for a litium ion by pulling the battery, updating the config files then plugging the new battery in.

storage, alot harder, i am thinking of having diffrent 'rails' so that i can attach to any battery, 1 lot for input and 1 lot for output each comprising of 3.3 5 and 12 volts so that you can use mixed battery voltages in the system (eg 12v sla 6v sla and a 3.3v litium) the voltages for all rails may be a minimum voltage or a regulated, i have yet to decide. regulated means more rails and solderin/work/cost

output, this is dificult and as yet undecided due to the other problems i have to solve such as where dose the regulation occur

the problem in my design so far is where i do the actual regulation, it may make sense to do it at the output but some battries will need a spcific regulated voltage and some inputs may provide multiple voltages that are both regulated and unregluated, at the moment i am using a rail design but i think i may need to change to a grid of switches with all the resoureces around the edges allowing me to route power to and throgh devices

more info soon