Portable 9v USB Charger





Introduction: Portable 9v USB Charger

how to build a portable charger. Does not work with iPod touch or iPhone
-1x 150ohm resistor (optional)
-1x toggle switch (optional)
-1x LED (optional)
-1x7805 voltage regulator (required)
-1x 9v battery clips (required)
-1x female usb connector (required)
solder (required)
soldering iron (required)
project case (optional)
scrap wire (optional)
if you do not want to use the switch then u can just solder the positive battery lead to the left prong of the 5v regulator. If your not going to use the LED then you wont need the 150ohm resistor. You can just use the second method
listed below.
cost of products(not including the solder and the soldering iron and the project case) using first method: $16.06 (after tax)
cost of products(not including the solder and the soldering iron and the project case) using second method $9.47 (after tax)
I compiled my parts into an altoids mint tin


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Please be positive and constructive.




Most smart phone batteries are 1500-3300mah.

A 9V battery has 50-400mah and at 500mw load has less than 300mah capacity.

You're also losing 30% of that 300mah thru the 7805 as heat.

Just exactly HOW much does this remaining 210mah charge your phone ???

Ref : http://www.powerstream.com/9V-Alkaline-tests.htm

I tried and didnt work but it was probably because I got the wrong transiter

ive tried this doesnt work on ipods although it probably would maybe work on some older usb charged devices like old cell phones

It is because he does not have a the data pins wired to anything. For Apple you need a data connection.

would this charge an iphone 4?

This is my first article, my apologies. You can click the "I" at the top of te pic and resize it. A 9v has about .3-.5mah which will charge your average phone or smartphone for a little under 2 hrs. Keep in mind I forgot to mention that it is an emergency charger, you don't just use it when u have an opportunity to use a wall charger. The 7805 5v converter takes te 9v down to 5v which is perfect for the USB to ensure to damage to the battery. This is a work in progress.
Thank you for your criticism I take it as if it were face to face. An electrical engineer looked at the project and thought that it was very well planned out and was constructed very well. Thank you so much for at least looking at my project .

no damage to the battery. sorry typo

This is not much of an instructable as there are no actual instructions. =)
When you are ready to post, there is an option to preview it first, and you would have realized that your pictures are too small to read the labels.
Just out of curiosity, why would you want to make a usb charger running off a 9v battery anyway? You could damage the device or battery since anything that comes with a usb charging cable it meant to charge off 5v, and the capacity of a 9v battery is about a quarter that of a single AA. Most devices these days draw at least 600 mA, but if you are talking about a modern smart phone ,tablet, or advanced media player, it's more like 850-1000 mA. So, in the case of the former, you will get about 50 minutes of charge time off a 9v battery, and in the case of the latter, it's more like 30 minutes, and you will be lucky if that's even one bar on the battery meter.