In this Instructable, I made a simple keyring charger.
It can charge your phone's battery with a standard 9v battery.
If you ever travel and find that your battery is dying, just get a 9v battery and use your keyring to charge your phone.
For this project you'll need:
- Car's USB charger
- Micro USB to USB adapter
- 2x 9v batteries or battery connectors
I removed the connector from a 9 v battery.
Then, I soldered cables to it.
Alternatively you can buy a battery connector.
I took apart car's USB charger and soldered battery connectors to it.
I could have used USB adapter without opening it, but I wanted to make it smaller, so I did open it.
I removed the LED from the charger.
Then, I covered everything with Sugru.
I also made a pattern with a screwdriver.
Once I was happy with the result, I half-plugged the charger in the phone and let it dry.
I also made a protective cap for the connector.
Finally, I attached another connector from a 9V battery to my keys.
Now the charger can be easily attached to the keys.
If you need to give your phone a boost, take off the keyring and use a 9V battery to charger your phone.
Charging speed and efficiency will depend on your phone, cars USB charger and the battery you will use.
Smaller phones with a high capacity 9V battery will charge better than big phones.