Help with a school project on solar power
I am going to buy a 10w 12v solar panel (I might be able to get a 40w for a bargain) which will charge a battery. Would it be better to get a 12v lead acid battery or a 12v lithium battery? Lithium batteries have DC jacks instead of normal terminals on lead acid batteries so how would I connect the battery in parallel to the 2 devices I want to power? A splitter like this would work but it connects it in series? Although I suppose it doesn't matter because I just need to show that it works at the expo but I'd like to use it now and then. The battery will connect to a 12v LED light and a 12v to 5v USB charger.
What about diodes? Do I need them? How will I make sure that the device charging doesn't get fried?
Thanks a lot, I appreciate it.
EDIT: A charge controller isn't necessary, is it? I'd also like to add in a switch to cut off power to the USB ports, power to the light and power to the battery from the solar panel. This would cause a problem if everything was connected in series.