Introduction: DIY USB Battery Charger for Cell Phone Lithium Ion Batteries From a Wireless Mouse Charger

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About: I just like to make stuff.

This a great way to charge up cell phone batteries without a cell phone, most cell phone AC adapters will not charge a battery efficiently as they are around 5 volts DC the phone itself has the battery charger inside of it. But I find these batteries have allot of uses around the home or man cave. This Mouse charger is for a Logitech MX Revolution wireless mouse. Which uses a Lithium ion battery.


I claim to be no expert I would not try to charge the mouse and cell battery at the same time. However this setup has worked great for me for recharging these old batteries. I have 1 of these batteries powering my keyboard for the last 30 days and only lost 1 bar of power, I got about 18 hours of power for the brass horse lamp before recharging. And keep in mind that these batteries are not new.
Happy Charging! 

FOR SAFETY REASONS I SUGGEST YOU DON'T ATTEMPT TO DO THIS! UNLESS YOU KNOW AND UNDERSTAND BATTERIES AND BATTERY TYPES ALONG WITH CHARGERS AS I AM BY FAR NO EXPERT AND KNOW JUST ABOUT ENOUGH TO BE DANGEROUS. 

Step 1: Tools & Parts

Tools:

Soldering Iron
Solder & Flux
Wire Strippers 
Black Tape

Parts:

3.7 Volt Cell phone battery
USB Cable with male & female ends

Step 2: Soldering the USB to the Battery

As you can see the battery is marked with + and - and if not then bust out the multimeter  to find positive and negative.

1. Dab a little flux on the contacts if your wires are already tinned your good to go if not be sure to tin your wire before trying to solder to battery.

2. With tinned wires in hand carefully solder wires to battery.

3. Wrap some black tape around the wired side to help keep wires in place.

Step 3: The Charger

On this charger there are 3 #1 Phillips head screws under the label and pull off the cover  to expose the charger. Break out the Multimeter to find the Positive side of the charger, The reading will be sporatic as it is a trickle charger there should be no solid steady current  from charger.

Step 4: Wiring the USB to the Charger

1. Drill a hole for the USB cable to fit though.

2. With your contacts identified dab some flux on the contacts and then solder your USB cable to the charger.

3. Replace the cover.

4. Plug in your battery for about 2 1/2 hours for a full charge.