I need to use Li-ion as a power supply for my PCB. I will use solar power (converted by solar cells with light from the nearest sun) for charging it (or them if I need 2 cells). But the problem is, I've never design or use a circuit like this before. This is not new, so I think you can help me to do this. After finding out for a while, I find that I can buy a CORTEX device of ARM easily in my village. If you've worked with this device, plz help me. Thanks.
It's not even worth thinking about the light from any other sun!!
"This is not new"
Indeed it isn't - so google should give you plenty of stuff!
But, why not just use a dedicated Li-Ion charger chip?
Rather: why not avoid fires, explosions and whatnot by using a dedicated Li-Ion charger chip
Erik
Indeed - Li-Ion charging is really not something for novices!
See: www.youtube.com/watch
have you considered that you are replying to an alien ;-)
Must be someone living in a dual-star constellation then, since the distance between stars are normally so large that that the second closest star is rather weak.
After read thise comments, I think I've found a solution. BQ24071 of Texas Instrument may be suitable for my application: - It has different pins for charging battery and loading system. - It supports output current up to 2-4A (this will fit 2A peak current of SIM300D) Do I have sth wrong?
By the way, let's consider about solar panel. Solar panel 6V/2.5W is the only one that output 6V I can find in my location (so, maximum current is about 410mA in theory and about 200-300mA in real). How long does it take to charge a 1200mAh Li-Po battery to full capacity? Is this solar panel okay, then?
Otherwise, I have to choose a 12V solar panel and a regulator will be need to output 6V for charging. In this case, how much power is enough (5W, 10W ...)
Another thing is regulator for microcontroller, would you recommend a selection for this (output ~3.3V from 4.4V) (saving as much as power is good)?