At present, Ni-MH batteries are used in different products. We should know a little about its use and maintenance. Nowadays, many Ni-MH rechargeable batteries are not worn out, most of them are worn out. Because the Ni-MH battery has a self-discharge reaction, it may cause the Ni-MH battery to be over-discharged if it is not used for a long time, causing the internal resistance to be too large, and the battery will not be charged. Repair it.

　　Specific steps:

　　The first step: completely discharge the battery after stripping, according to the current status of the battery, short-circuit the battery directly or use a 1 ohm resistor when the load is discharged until the terminal voltage is close to 0 volts. It takes about 5-10 hours. This can prevent the battery from being short circuited and burned out accidentally after adding water, and it can also reduce the electrochemical corrosion when immersed in water.

　　Step 2: Open the safety valve. There are four holes at the positive electrode of the battery of brands such as Sanyo and SONY. You can see the rubber cap of the safety valve. Use a thin iron wire (I used the iron foot 1/4 resistor pin) to bend into a U shape. Then insert about 2 mm from the bottom of the rubber cap toward the center. In this way, the safety valve is forced to open, bent into a U-shape in order not to damage the rubber cap.

　　Step 3: Use freshly boiled water to scald the battery, wait until the positive electrode no longer bubbling, but remember not to boil the battery, but to boil the water and burn it.

　　Immediately put it in a bottle of cool (room temperature) purified water, and wait for about 1 minute. At this time, part of the water has been inhaled. Immediately twist the cap and squeeze the bottle for about 10 seconds to make more water enter the battery:

　　Step 4: Take out the battery, wipe it dry, pull out the U-shaped iron wire, and cover it. It is best to use a large Phillips screwdriver and a small hammer to dent the center of the positive cap slightly to increase the sealing degree of the safety valve