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




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! 


Step 1: Tools & Parts


Soldering Iron
Solder & Flux
Wire Strippers 
Black Tape


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.



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    11 Discussions


    Forgive me if I am being obtuse but how does this connect to your mouse?


    7 years ago on Introduction

    Does the original mouse still charge on this when you were done?
    Presumably NOT with your "usb battery" attached, but when detached, it LOOKS like the normal operation should be unaffected.

    Minor, but IMPORTANT note...
    this works only with mice that use li-po batteries, like that particular logitech the author listed.

    I give the warning on account of the fact that all the re-chargable wireless mice I personally have, use NiCd or NiMh, and those chargers will do very bad things to a LiPo cell phone battery. VERY bad things.

    Second warning...
    Though USB is VERY convenient as a connector...
    I'd be very VERY worried that someone would come along, and plug that battery straight into a computer usb socket to recharge. Since the cellphone batteries have built-in protection circuits, it would probably not be a major disaster... but it likely WOULD kill the battery.

    Dunno what would be BETTER, but the "paranoid about other people's stupidity fairy" tells me it's just not sound practice.

    5 replies

    Reply 6 years ago on Introduction

    Cell phone LiPo cells have vary limited protection, usually just overheat.
    Most USB ports are current limited, so if plugged in for a short time it will do no harm, but if left plugged in or plugged into a non limited port (like USB3 or some cheap expansion cards) you will kill the battery.


    Reply 6 years ago on Introduction

    Erm... I'm a beginner at this, so you can't use a computer to charge it because the voltage it to high???

    The computer is not a LiPo charger.
    If you plug it into your PC it may do very bad things to the battery and or USB port.
    I would advise for you not to do this untill you have a better understanding of chargers & battery & types... less you burn some thing down.

    I don't want to discourage you... All I am saying is get some basic knowledge of batteries and types of batteries along with charging systems as there are many types of batteries & charging systems.

    I have little knowledge myself and know about enough to be dangerous.

    Must say I love your little blurb of "...AND KNOW JUST ABOUT ENOUGH TO BE DANGEROUS." Reminds me of part of my own personal saying "...I know more than enough to be dangerous..."

    I must say @ironsmiter has a good point about others stupidity... most people assume when they see a USB cable that the device can be connected to the computer.... I know USB connectors make a very handy connector, but I am wondering why you used USB.... was it just what you had on hand? Personally I would have either used a barrel-type jack, TRS jack (typ. headphone type jack), or a RJ-45 (think CAT-5 (Ethernet) or Telephone jack)

    1 reply

    Well I have a ton of USB cables and and rather toss them in the scrap pile they getting used up. The connectors were easy and on hand.

    And as far as other people stupidity I can't argue with that.... However I believe that most people who may do this would not like other folks going through there Lab and messing with the natural order of things.

    Winged Fist

    7 years ago on Introduction

    Grasshopper – Another great instructable! You should consider expanding this instructable (or creating a new one) to include new uses for an old cell phone battery, like powering an Antique carousel Brass Horse Lamp;-)

    I'm sure many Instructables regulars have aplenty of old cell phone batteries lying around, and if they're like me, it never occurred to them that these old batteries could be adapted with a usb plug to power new inventions!

    Also a great way to keep these toxic little bricks out of the waste stream!;-)

    Well done!

    Hello Ironsmiter:
    Yes my mouse will still charge using this charger. And as I stated I am no expert on this subject I do know that my mouse uses a Lithium ion battery so that is why I chose to to use this charger for this. I would not try to charge both at the same time.

    There would be nobody in my mancave to plug theses batteries into any PC USB port.