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Topic: Connection between 140 A/h lithium battery and arduino (Read 74 times) previous topic - next topic

marcoalberto

Good evening,
I would connect a voltmeter between an arduino and li-ion battery to know the voltage of battery.
Could you give me kinds of voltmeter that works with arduino, please?
Ps: Sorry for bad english.

DVDdoug

Read Analog Voltage Example.

The Arduino can be damaged by voltages greater than 5V (and it can't directly read voltages greater than 5V).   Assuming your battery is more than 5V, you'll need a voltage divider (2 resistors).    The resistor values are not too important, it's the resistance ratio that's important, but resistor values that sum to around 10K would be reasonable.

Then of course, you'll need to scale the ADC reading appropriately in your software for your particular voltage divider.

If the voltage is unknown and/or you want to be extra-safe, you can add protection diodes to the voltage divider.

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