The battery is broken. Generally, the batteries of led flashlights on the market are lead-acid batteries. Charging circuits are all power frequency transformers plus simple rectification, or series plastic capacitor current-limiting rectification.
The fatal disadvantage is that you can't stop charging automatically after filling, and you can't limit the pressure with constant current. After several long-term charging, the battery was charged and scrapped.
If the charging time is too short, the battery will be under-charged and the electrode plate will be vulcanized and damaged. There is no power failure detection circuit, and the battery cannot be automatically powered off after discharge, resulting in battery over-discharge damage.
A good flashlight is a lithium battery, and the charger and LED drive circuit have CB and other safety and environmental protection certifications.
Second, the common faults of rechargeable flashlights
1, flashlight circuit is open.
The internal wiring is open, and the brass spring conductive piece inside the plug is deformed. Find out whether the broken part is connected or whether the spring piece is deformed and shaped.
2. The electronic components of the charging circuit are damaged
Check the buck capacitor and rectifier diode. Replace the damaged parts.
3, rechargeable battery failure
One is lead-acid battery, and the battery plate is easy to age. Cleaning the electrode plate and replacing it with distilled water (or purified water) is even worse. )。 Part of it can be repaired.
The other is a nickel-hydrogen battery, or a nickel-cadmium battery. This kind of battery may not have expired, but it can't be charged due to memory effect, which is mostly caused by insufficient charge and discharge during use. At this time, the battery can be discharged, and it needs to be recharged with a discharge current limiting resistor, and some of it can be repaired.
Third, what if the rechargeable flashlight can't be charged?
The easiest way is to find a good fully charged battery and connect it directly with the over-discharged battery to charge it. If the voltage can rise, charge it with a charger. If not, I suggest changing it.
Fourth, the maintenance measures of rechargeable flashlight
1, don't lose power when storing.
The state of power failure means that the battery is not charged in time after use. The longer the battery is idle, the more serious the battery damage will be.
Don't expose yourself to the sun
Can't be exposed to the sun. If the temperature is too high, the environment will increase the internal pressure of the battery, and the battery pressure limiting valve will be forced to open automatically. The direct consequence is to increase the water loss of the battery. Too much water loss will lead to the decrease of battery activity, accelerate the softening of electrode plates, and cause fatal injuries such as bulging, heating and deformation of the shell when charging.
3, regular inspection
In use, if the discharge time suddenly drops, it is likely that at least one battery in the battery pack has a short circuit phenomenon, such as grid fracture, plate softening, plate active material falling off and so on. At this time, you should go to a professional battery maintenance organization for inspection, maintenance, repair and assembly in time.
Try to avoid instantaneous high current discharge, which may easily lead to lead sulfate crystallization and damage the physical properties of battery plates.
5, correctly grasp the charging time
In the process of use, we should master the charging time according to the actual situation. Generally, the battery is charged at night, and the average time is about 8 hours. The battery will be full soon, and it will be overcharged if it continues to charge, which will lead to dehydration and fever of the battery and reduce its life. Therefore, the battery is charged once when the discharge depth is 60%-70%.
6. Avoid unplugging when charging.
Loose output plug of charger and oxidation of contact surface will lead to heating of charging plug, and too long heating time will lead to short circuit of charging plug, which will directly damage charger and bring unnecessary losses. Therefore, when the above situation is found, the oxide should be removed in time or the connector should be replaced.