Can you use a 1400 mah battery to replace 500mah battery?

Yes, you can use a 1400mAh battery to replace a 500mAh battery, provided that the voltage and connector type are compatible. The higher capacity means the device will run longer between charges. However, ensure that the device can handle the increased capacity without overheating or causing other issues. If the device is not designed for such a battery, it may lead to performance problems.