Battery Powering Arduino Uno
Created on: 8 August 2012
Updated on: 24 February 2023
How to battery power an Arduino Uno. The video that follows shows how to make up a cable to connect a 9V battery to an Arduino Uno. A 2.1mm barrel connector is soldered to a battery clip with the positive (red) wire connected to the center of the barrel connector. This type of battery connector is also available already assembled.
This is probably the cheapest way to battery power an Arduino Uno, but has some disadvantages. Continue reading this article for an explanation and alternate methods that can be used to battery power an Arduino Uno.
The pre-loaded blink program starts flashing the on-board LED on and off after the battery is plugged into the Arduino.
A small 9V battery is not practical for powering an Arduino Uno for a long time. This type of battery is fine for intermittent use as well as for use during development and experimentation. To power an Arduino Uno for longer periods of time, a bigger battery is needed.
How to Battery Power an Arduino Uno
Below are a few different ideas on how to battery power an Arduino Uno.
Small 9V Battery for Powering an Arduino Uno
As already discussed above, small 9V batteries do not last long when powering an Arduino Uno board. Rechargeable batteries are an option.
The voltage of the battery will be about 9V if six 1.5V cells are used in the battery holder. If rechargeable cells are used, the battery will produce about 7.2V.
12V Sealed Gel Battery
An alternative to using a 9V battery as shown above is to use a 12V sealed gel battery. This type of battery can be connected to a trickle charger or solar charge system.
Battery Voltage and Charging
It is important to note that when using a fully charged 12V lead acid gel battery, the output voltage is actually 13.8V. When the battery is charged, either using a trickle charger or solar charge controller, the charge voltage can be up to 14V or slightly higher. If the Arduino Uno is connected to the battery when the charger is also connected, the Arduino Uno then receives the full charge voltage. This voltage is above the recommended input voltage range of 7V to 12V, which means the Arduino will tend to run hot.
Keeping the Input Voltage in Range
A solution to keep the input voltage to the Arduino lower is to use a 9V switched mode regulator between the 12V battery and the Arduino Uno.