in 18650 resistance detector

[liudengyuan]

Members electronics enthusiasts around the world, Hello, everyone, I would like to help a 18650 lithium battery internal resistance and voltage tester circuit, please help me, my mailbox [email protected], thank you very much

[6666]

I searched google and found this

A new high quality 18650 battery will have an internal resistance under 100mOhms.

A used up 18650 battery will have a resistance 400mOhms or more.

You can buy online good quality low priced battery charger/dischargers for about $38.00 that can show you the internal R of your battery's.

And found this

Measuring a single 18650 battery's internal resistance is simple. All you need is a 4 ohm 5W power resistor or similar and a multimeter. Four common 1W 1 Ohm resistors in series would work, but get hot !
) First, measure the battery's voltage when charged. This is V1
2) Next, connect your multimeter leads to each side of the resistor and briefly connect the resistor across the battery. Note the voltage reading, this is V2.
3) Measure your resistor to get its precise resistance, this is R

4) The battery's internal resistance (Ri) is calculated with the formula:

Ri = (V1-V2)*R/V2

Example: cell measures 4.2V unloaded, 4.0V when connected to a 4 ohm resistor has an internal resistance of 200 mOhms (0.2 ohms)

[liudengyuan]

Hello, friend. I want to test the resistance of the size of the value 18650, to use high-current battery,

[liudengyuan]

Your best friend, you can make or give me circuit it? I need to read its voltage and internal resistance data, low induced 0.1 milliohms maximum voltage 10v, need sorting 18650, so the need for the upper and lower internal resistance and voltage limit selection, thank you

[bklein]

Skyrc.com mc3000 looks perfect but I don't have one - yet.

[liudengyuan]

I need a pulse detector circuit and the internal resistance of the battery voltage detection circuit 18650, which friends so, please contact me, thank you

[6666]

I searched google and found this

A new high quality 18650 battery will have an internal resistance under 100mOhms.

A used up 18650 battery will have a resistance 400mOhms or more.

You can buy online good quality low priced battery charger/dischargers for about $38.00 that can show you the internal R of your battery's.

And found this

Measuring a single 18650 battery's internal resistance is simple. All you need is a 4 ohm 5W power resistor or similar and a multimeter. Four common 1W 1 Ohm resistors in series would work, but get hot !
) First, measure the battery's voltage when charged. This is V1
2) Next, connect your multimeter leads to each side of the resistor and briefly connect the resistor across the battery. Note the voltage reading, this is V2.
3) Measure your resistor to get its precise resistance, this is R

4) The battery's internal resistance (Ri) is calculated with the formula:

Ri = (V1-V2)*R/V2

Example: cell measures 4.2V unloaded, 4.0V when connected to a 4 ohm resistor has an internal resistance of 200 mOhms (0.2 ohms)

I am not exactly sure what you are asking but the instructions to measure the internal resistance of a single 18650 are above
you just need a multimeter and a resistor , read the open circuit voltage V1, then apply resistor to put load on battery , read the LOADED voltage V2, and put the two voltages into formula and calculate.
A new high quality 18650 battery will have an internal resistance under 100 milli Ohms.