First remove the battery, wait for five to ten minutes, then install the battery to charge again, see if there is no reaction, if there is no reaction, then use a charger slightly higher than the normal mobile phone charging voltage to charge, strong activation, repair and wake up due to too deep self-discharge and sleep protection of the lithium battery. For long-term lithium batteries that are not used for various reasons, the voltage will gradually decrease due to self-discharge, and when the voltage is lower than the minimum threshold voltage set by the lithium protection board (generally, the lithium battery ranges from 2.5V to 3.0V), the power output will be automatically cut off. At this time, the voltage can not be measured outside the lithium battery with a multimeter, and it can not be charged with a mobile phone and universal charger, which is called battery dormancy.