I recently purchased a 3.7V rechargeable lithium battery and I'm attempting to charge it using a TP4056 module. However, after charging, the blue light on the module indicates that the battery is charged, yet my multimeter shows the battery voltage at only 1.3V. I even got a second TP4056 module, but the issue persists. I tried a new battery as well, but it also doesn't read above 1V. It seems unlikely I've ended up with two overdischarged batteries. Additionally, I've observed that while the blue light stays on, the red light is flashing. What steps should I take next?
2 Answers
Another thing to consider is the power source of your TP4056. Ensure that you're using a USB port that can provide at least 1A; if it's not sufficient, the charger might struggle. Since you mentioned using a phone charger with both 9V 1.67A and 5V 2A outputs, this should generally be adequate, but it's worth testing with a different cable or charger just to rule out any issues there.
It sounds like 1.3V could indicate that your battery might be damaged. First, make sure your multimeter is functioning properly—if its battery is low, it can give inaccurate readings. Have you also checked if the battery terminals are clean? If everything checks out and you're still facing low voltage, consider the possibility of overdischarged batteries. I suggest giving the current battery a longer charge and monitoring the voltage carefully.