# What happens if you have too little voltage?

Ok so im still struggling to fully understand the basics of electrical circuits so forgive me of this question seems noobish

I want to hook up a group of solar cells i bought from Radio Shack and use a voltage regulator to have a stable 5v power supply (being a noob i have no idea how to make sure the current isnt too high either). Now my question is since the power will be solar therefore not always 100% stable, what happens if its dips too low?

For example lets say im charging a USB device connected to a female usb cable (powered by the solar energy), i think standard USB ports have a power output of 5v. What happens if i dont have enough solar power and it drops to say 3v? Does it stop charging altogether? Does it trickle in a small amount of energy? Does my device blow up?

Any help would be awesome

What is it that you are trying to charge.
Generally, trying to power something off solar power directly is always problematic
due to the fact that Solar panels are essentially current sources and work best if they are directly charging a battery.
You can then regulate the batteries voltage , and use the regulated voltage to power whatever you like.
The battery ensures that in the absence of sufficient sunlight, the powered device still works.
Without a battery, all that will happen when there is insufficient sunlight, is that the supplied voltage will be less than 5V
and how that affects what you are powering depends on what it is.

No particular item in mind to power, just a fun alternative source of energy (9V are pricey as Hell lol). I was thinking charging a battery source might be best but im unsure what type of battery i should look into for this. Rechargeable ones sound like what i would need. Don't know much about capacitors but those sound more like on the fly quick storage than long term solutions like this.

Solar Cell Array ---> Rechargeable Batteries ---> Whatever voltage level regulator --->Power stuff

Remember you always need a blocking diode when connecting a solar cell to a battery as
an unlit solar cell will drain away the battery rapidly.

Such a diode means that too little voltage at the cell means no current can flow from it to
charge the battery.

Many devices designed to run from USB are expecting 4.75 to 5.25V range, what
happens outside this range depends on the device. Overvoltage is always bad news.
Undervoltage usually causes malfunction, but not usually damage.