Hello, I have set up my circuit using the MP2615GQ IC to charge a 2S lithium polymer battery, but when I set the sense resistor (RS1) to 100mΩ, the charging current should be 1A, yet it charges the battery at 200mA, and the voltage across the RS1 resistor is 20mV. Even when I reduce the RS1 resistor to 50mΩ, I still get a charging current of 200mA. What steps should I take to achieve a 1A charging current? I would appreciate your assistance
Looks like you are stuck at 10% charge, not having bothered to read the datasheet I would suggest generally this is due to the battery voltage being out of range ( like less than 2.5V ) or the temperature being too hot or too cold. Might want to look at those things
Thank you for your response.
The battery voltage I used in the design is around 6.5-7.2 V, and the environment where I tested it is at room temperature. Since I also thought the issue might be due to temperature, I replaced the 10k ohm NTC resistor with a regular 10k resistor, but there was still no change. Do you have any other solution suggestions?
Thank you in advance for your help.
Might I suggest an Eval board? Did you measure the voltage at the NTC pin and verify it was in the correct range for 100% charge? Perhaps you have an incorrect component. What is Vin? could Vin be in current limit?
Hello,
I don’t think I’m using the wrong component; I used the components on the evaluation board as a reference. Also, the NTC pin is within the correct range, and the area where I’m testing is at room temperature. I am using a power supply as the input as well. In the circuit I built, when the battery side is open, the output voltage is set to 8.3V. However, when I connect the battery, the output voltage rises by 200mV above the battery voltage. Could this be the source of the problem? Don’t we need to apply a voltage around 8.4V to draw a higher current when the battery is connected?
Thank you for your help.
Of course you don’t think you are making a mistake, nobody does. Look around in life, mistakes abound. An eval board is not expensive and can save you more time than it costs. Are you sure your batteries are in good health. I don’t see how the output voltage can be above the battery voltage? Isn’t the output voltage connected to the battery terminals?