I messed up on a design and I have the boards made now. It is a solar panel and 4 volt re chargeable battery configuration. I neglected to put a diode inline to the chip. If the battery were to be connected in reverse the surge through the solar panel would I think would blow the fuse before the chip had any damage.
The board draws a maximum of 36 mA when running. The 16 LEDS, only one is on at a time, one fades up as the next one fades down alternating on and off. The two center LEDS run at 50% duty cycle. The pins sink current to turn leds on.
The solar panel maximum current when charging the battery is 60mA
One thing I see is a .125A fuse has a 7 ohm cold resistance, I don't know much about fuses but that might be a problem. If I can go to a more standard fuse like .5A I think it would be better.
The other problem is the solar panel would fry if the battery was connected in reverse. I was going to protect with a diode but don't see how to do it as current has to go both ways charging and powering the circuit.
Finally got the vodeo working, this is what it does. A simulated rotating light for a solar lighthouse.
When I disconnect the clip I am just simulating darkness on the solar panel because the panel is outside my window. I use the ADC and the 1V on chip reference to shut it down when there is enough voltage on the panel. Then I put the chip to sleep and it draws about .04A