How to measure the internal resistance of a Lipo battery?

Measuring the internal resistance of a LiPo (Lithium Polymer) battery can give you an indication of its health and performance. Here are the steps to measure the internal resistance of a LiPo battery:

Charge the battery: Make sure the battery is fully charged before measuring its internal resistance. This will ensure that the battery is at its optimal state.

Disconnect the battery: Disconnect the battery from any load or charger before measuring its internal resistance.

Connect the battery to a load: Connect the positive and negative leads of a load, such as a resistor, to the positive and negative terminals of the LiPo battery. The load should have a resistance value of at least 1 ohm.

Measure the voltage drop: Use a multimeter to measure the voltage drop across the load when it is connected to the LiPo battery. Make sure the load is connected for a few seconds to allow the voltage to stabilize.

Calculate the internal resistance: Use Ohm’s Law (R=V/I) to calculate the internal resistance of the battery. R is the internal resistance, V is the voltage drop measured across the load, and I is the current flowing through the load (which can be calculated as V/Rload, where Rload is the resistance of the load). The internal resistance of the LiPo battery is equal to the calculated value minus the resistance of the load (R = V / I – Rload).

It’s important to note that measuring the internal resistance of a LiPo battery should be done with caution and only by those who are experienced and knowledgeable in handling LiPo batteries. LiPo batteries can be dangerous and should be handled with care to prevent short-circuiting or damaging the battery.