How do you determine battery voltage?

The voltage present is equal to the amount of resistance times the current. The formula is: Voltage (E) = Current (I) x Resistance (R), or E = IR.

What does voltage measure in a battery?

Voltage is the unit of current in your battery and is measured in volts. If you think of your battery as a water pipe, the voltage would be the water pressure in the pipe. This pressure makes the current flow through the battery, delivering power to your device.

How is current measured?

Current can be measured using an ammeter. Electric current can be directly measured with a galvanometer, but this method involves breaking the electrical circuit, which is sometimes inconvenient. Current can also be measured without breaking the circuit by detecting the magnetic field associated with the current.

How does ADC measure voltage?

The ADC reports a ratiometric value. This means that the ADC assumes 5V is 1023 and anything less than 5V will be a ratio between 5V and 1023. If your system is 3.3V, you simply change 5V out with 3.3V in the equation.

How to measure the charge of a CR2032 battery?

Let’s rephrase the key point: Instantaneous voltage, by itself, tells us nothing about the CR2032 charge level. The common method of dealing with this is by the use of a Coulomb counting battery fuel gauge. There are many hardware options.

Do I need a fuel gauge on a CR2032?

However, devices that use the CR2032 are typically very cost sensitive. Sometimes they are even disposable, and the battery is not replaceable. Therefore a fuel gauge is routinely omitted, as is current sensing. Typically, the battery voltage is the only metric the firmware has.

What is a CR2032 power supply?

Typically a device that uses a CR2032 is a low duty-cycle device; a very low power device that spends most of its life asleep. It then wakes up for short periods, fulfills its purpose in life, and goes back to sleep. This is especially the case for BLE IoT peripherals. If your device is in this category, life gets easier.

What do you think about the Silicon Labs CR2032 lithium battery discharge firmware?

The Silicon Labs reference firmware for these modules has less-than-spectacular charge level measurement, and I seek to improve it. Two aspects of CR2032 lithium battery discharge performance need to be understood. Firstly, the voltage does not change very much over the first 75\% of the discharge.