Lithium battery capacity measurement method steps
1. Simple method of constant resistance discharge. You need to use a multimeter and a high power resistor. First, charge it fully. You can charge it in a cradle, for example on the plane or on your cell phone. Connect the fully charged load of the battery to this resistor, which can usually be a 10 ohm 5 W cement resistor. After discharging until the voltage is less than 2.75 V, the total time capacity of discharge = 0.37 A*time is obtained. relatively simple, but there is some error.
2. Formal method: Use a battery capacity tester, charge at 4.20V first, then let it discharge for 1 hour at a constant current. The arbitrage method is 0.2 times. The capacity is 1000 mAh, discharges at a constant current of 200 mA. When the discharge reaches 2.75 V, calculationez time * constant current = battery capacity. This is done in accordance with the National Lithium Battery Regulation 18287. If it is a nickel-metal hydride battery, the same is true, except that the charging method is not constant voltage and that the discharge is cut off at 1.0 V per cell. This method requires special equipment.
2. 18650 lithium battery capacity measurement steps
Method 1:
Have a professional battery capacity separation cabinet
If it is acts of an individual. If so, look for an adjustable load resistor and a current adjustable DC power supply to calculate battery capacity based on charge and discharge time.
Charge current × charge time = battery capacity (from 2.7V). or 3.0 V to 4.2 V)
or
Discharge current × discharge time = battery capacity (4.2 V discharge to2.7V or 3.0V)
Method 2:
The first step is to fully charge the battery to the rated voltage, which is usually 4.2V.
The second step is to discharge the battery to the rated voltage and record the discharged power. , the voltage is usually 3.0 V
The third step is to charge the battery to its normal capacity, usually set to 3.8 V-4.0 V
The capacity recorded in the second step is the battery capacity.
Method 3:
Use the power meter integration function to measure the lithium battery capacity required by the device. I usually use PA310 Zhiyuan* power meter to measure lithium battery. Ability. After capacity, just choose a battery with larger capacity for device usage.
How to measure cell phone battery voltage?
Lith battery capacityium is generally high, but the uF range of multimeters is limited and lithium batteries have plenty of protection circuitry if the multimeter passes through the negative diode end of its internal fuse circuit. By measuring, the current will be cut off and flow through the transistor. This is even more troublesome, and the internal structure of the battery is relatively simple, and it is equivalent to a capacitor after a power drop. Under normal circumstances, it is not recommended to use a multimeter to measure battery capacity. No one uses a multimeter to measure battery capacity, and most meters can't measure a number. Unless your watch is awesome.
When the battery is fully charged, the battery voltage is 3.8-3.9V.
As the energy is consumed, the voltage gradually increases lower, when the voltage is lower than 3.7V,Most mobile phones turn off automatically.
The charging voltage of the mobile phone battery is 4.2V~5.5V. If the battery voltage exceeds 3.92V, it will enter the overload protection state. overloads.
Currently available cell phone chargers are typically 5V.
Battery durability: Before the battery leaves the factory, the manufacturer has activated and precharged it , so the battery has residual power. Some friends said that the battery is charged according to the adjustment period and standby. time is still seriously insufficient. Assuming the battery if it is indeed a genuine battery, in this case the adjustment period should be extended and then fully charged and discharged 3-5 times.
If the newly purchased cell phone battery is lithium-ion, the first 3 to 5 charges are usually called periode of adjustment and must be charged for more than 14 hours to ensure full activation of lithium-ion activity. . Lithium-ion batteries do not have a memory effect, but have high inertia. They must be fully enabled to ensure optimal performance for future use.
Some automated smart fast chargers only indicate they are 90% full when the light changes. The charger will automatically switch to slow charging to fully charge the battery. It is best to use the battery after it is fully charged, otherwise the usage time will be shortened.
Lithium batteries do not need to be specifically discharged before being charged. Improper discharge will damage the battery. `
When charging, try to charge slowly and reduce fast charging; the time should not exceed 24 hours.
After three to five complete cycles ofcharging and discharging, the chemicals inside the battery will be fully “activated” to achieve optimal usage.
Please use the charger from the original manufacturer or a reputable brand. For lithium batteries, use a special charger for lithium batteries and follow the instructions, otherwise the battery will be damaged or even dangerous.