Professional battery capacity test method analysis

　　Author ：Iflowpower – Portable Power Station Supplier

Lithium-ion battery capacity self-test CECT9898 OEM mobile phone lithium ion battery nominal capacity 3800mAh, its battery volume is equivalent to other brands of mobile phone 1500mAh battery volume. Use your hands existing hardware | Tools and expertise, your own capacity test of your own CECT9898 OEM phone. According to GB / T18287-2000 "Total standard of lithium ion battery", mobile phone battery capacity is simple to describe: in 20±At 5 ¡ã C temperature, the charged battery is discharged from the 5-hour rate to the supplied power when the voltage (2.

75V) is terminated. Based on this, it is designed, and the discharge test circuit is designed. The main body of the discharge circuit is a constant current source, 3V auxiliary power supply | Regulator selection dry battery.

First use another mobile phone battery to debug circuit, then open the dry battery (the bias of the constant current source is broken), the discharge current becomes zero, then replace the CECT9898 mobile phone lithium-ion battery, connect the battery, and start timing ,test. Surveus on November 23, 2007, ambient temperature 16 ¡ã C. Test battery (S / N: HSY07102647) has been fully charged and discharge, no less 12 hours per charge, discharge to mobile phone automatic shutdown.

The battery is charged with a mobile phone for 12 hours in the second day, and the phone will be charged twenty minutes before the test. Use the DT9206 digital multimeter Self-disposing charge voltage 4.20V, battery fully overflow no-load voltage 4.

17V. Because the voltage dropped from 2.80V to 2.

75V, it is too late to record, so the final one minute data is not included in the account. According to the battery capacity, the battery capacity is the diaphragm area in the current - time characteristic, about 1680mAh (mA). This test causes an error in this quarter by: 1.

Discharge time (366 minutes) slightly less than 5 hours of national standards, that is, the discharge current is too large, considering the internal resistance element of the battery, will make the test results slightly Be small. 2. The constant current source accuracy is not enough, lower than national standard requirements (within 1% of current change), tight transistor temperature changes.

3. The accuracy of the current table is lower than the national standard requirements (should≤0.5 level accuracy) 4.

The battery charging method is slightly different from the national standard requirements (the national standard requires charging moment not greater than 8 hours), but meets the battery maximum capacity conditions in use. Based on this, this personal test is about 1700mAh, far below the nominal capacity of 3800mAh. Explanation, you can ensure that the above test data is determined, but this test is only personal behavior, its test principle, procedure, and conjunction only for personal point of view, and does not act as discriminative basis.

two. Current self-measurement does not have a mobile phone specific voltage regulator power supply, this test power is used to clamp the battery, and connect to the mobile phone with universal charger. Test Instruments | Outer Table is the MF47 digital multimeter, and in the following test current value, the integer current is measured by 500mA, and the small digital current is measured with 50mA file.

Current length accuracy±2.5%, when the gear switch is switched, the two tables are connected in short-circuit lines. Quiz area signal strength: G network 4 grid, C network 3 grid.

(1) Pack CDMA card shutdown current: 1.1mA; boot current: the most about Mo 200mA; standing current: g / c dual mode, CDMA form. The pointer is swayed between 25 and 35mA after the LCD is closed, and then the rock between 3 to 25 mA is changed, the rock is relatively strong, about 2.

5 seconds once, and most of the time is around 3mA; when switching to video form When transferred to the form of the CDMA, the G network shows no signal, and the pointer is swaying between 36 ~ 53mA in three minutes after the screen is turned off, and then the rocking regularity is the same; the sound is in the same way, the LCD Low brightness and no operation, current 43mA, LCD is 1.6mA after the LCD is closed, and when the LCD is low, the LCD is swayed between 94 to 105mA; in the form of the CDMA, 10011, after the LCD is closed, call Uniform current is about 250mA. (2) When the GSM card is installed, when the series current table introduces the resistance, it is automatically shut down when the network is registered after the boot is turned on, and the maximum current is close to 300mA.

Short-charged current table and decrease the connecting line to power it, but it is often automatically shut down after booting, and it is estimated that the current is caused by contact with the network. This form is less quiz, the data is as follows: shutdown current 0.9mA; Stope current: G / C duplex, when the LCD is closed, it is swayed between 3 to 25 mA, sometimes rushed to 100 mA, and accompanied by automatic Shutdown; in the form of GSM, the C network shows no signal.

After the LCD is closed, it is reduced to between 3 to 25 mA swing; the current swing is more messy, no regularity can be followed; when the LCD low brightness is not operation, the current is about 48mA; Make a call under the form of GSM, immediately shut down, call current test failure. (3) When the G / C dual card, automatic shutdown when the network is started, short-circuiting the current table and decreases the connection line, and the measured data is as follows: Shutdown current 0.9mA; Stope current: Under dual mode, in LCD The pointer is swayed between 28 ~ 53mA in the second half, and then becomes between 5 to 45 mA swing; in the form of the CDMA, the pointer is swayed between 25 to 40 mA in half a minute after the LCD is closed, and then becomes 3 ~ 24mA swing; when in the form of the GSM, the LCD is swayed between 3 to 25 mA after the LCD is closed; the pointer sways between 70 and 85mA when the LCD low brightness is not operated.

(4) Call current is 1.0mA; LCD is 2.2mA, LCD low brightness, current 43mA, medium brightness is 107mA; high brightness is 155mA; LCD low brightness plus keyboard light time current 78mA; LCD low brightness plus 95mA (640 Times; 480 high-quality) is 95mA; medium volume MP3 is exterminate, the current is even about 150mA; 5) Other keyboard locks do not affect the current; the current will add.

Test decomposition: 1. When the network is standby, the current change is strong, the battery voltage is low, which may be that the C-network mobile phone can minuse the battery capacity to be very thorough. (C network mobile phone automatically shut down) Boot, while the G-N-network can be); 2.

Dual card dual standby current is higher than the single standby; There is still a single mode in dual mode, and there is no significant difference in power consumption; 5. There is no significant difference between the dual card single standby and single-card single-standby electricity; 6. Keyboard light consumption current about 35mA7.

LCD low brightness power consumption of about 41mA , Medium brightness consumption is about 105mA, high brightness consumption of approximately 153mA; 8. Built-in photograph (640Times; 480 high-quality) machine consumption of about 35mA; 9.G Internet mobile phone and base station When connected to the CN network ; 10.

G network call time.