Lipo Battery Voltage Tester
Introduction Lipo Battery Voltage Tester:
This Lipo Low Voltage Alarm could be used to get the voltage from a Lipo battery. It connects to the lipo battery’s balance plug and outputs the voltage of the individual cells and the total voltage of the battery pack. It also has an onboard alarm that beeps when the battery voltage gets low. Use this alarm to stop draining the Lipo battery completely and this increases battery life or preserves the battery performance. This voltage display is used for 1S~8S lithium battery detection and automatically detects the voltage and total voltage of each cell of the lithium battery. It supports reverse connection protection. It allows you to know the working status of your battery anytime, anywhere, so that your battery will not be damaged by over-discharge or overcharge. When the voltage is lower than the set value, the buzzer will sound or the red LED light will flash; the factory default setting is 3.3V. Press the button to change the voltage setting and automatically save the user's current setting.
The voltage display is used for one-eighth lithium battery detection. It can automatically detect the voltage and total voltage of each cell of a lithium battery. It supports reverse connection protection. It can let you know the working state of your battery anytime and anywhere so that the battery will not be damaged by over-discharge or overcharge. Whether in flight or idle state, the display can be inserted into the battery balance charging connector to understand the battery power status. When the voltage is lower than the set the buzzer will sound and the red LED light will flash; when the setting value is 3.3V press the key to change the voltage setting value and automatically save the user's current setting value.
Spceifications:
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Voltage detection accuracy: 0.01V
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Group voltage display range: 0.5V-4.5V
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Display range of total voltage: 0.5V-36V
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1s test mode voltage range: 3.7V-30V
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Low voltage buzzer alarm mode: 2S-8s
Circuit Operation:
On production lines when manufacturing cells for lithium-ion batteries, OCV testing plays a key role in detecting defects. OCV is a battery’s voltage when it is not connected to any load. Batteries exhibit self-discharge characteristics, that cause their OCV values to decline gradually over time. When the battery has an internal defect, self-discharge increases. On-production line testing serves to detect batteries whose OCV has decreased beyond the defined value so that they could be excluded as defective. Manufacturers carry out the OCV test in each process after initial charging. Notably during the aging process, OCV shall be measured at a constant time interval with high accuracy, to evaluate if it is a small change due to self-discharge. It requires generally 100 - 400 hours to detect defective cells.
Batteries’ OCV varies with temperature. A change of just 1°C in temperature at the time of measurement can cause the OCV value to change by several hundred microvolts. It is important to keep the temperature environment constant during measurement. The instruments’ temperature compensation function converts measured values to voltage values at a reference temperature.
This thermistor is for monitoring the temperature near the heatsink on the input/output board because the temperature could be relatively high during discharging. The thermistor temperature information is sensed and stored in the ADP5065 Charger Status Register 2 and is monitored by the MCU board through the I2C bus. There are 2 headers on the input/output board for the external fan connection with a configurable pulse-width modulation (PWM) signal assigned. If the thermistor temperature is less than 45°C, the PWM signal to the fans is set at 50% duty cycle by the MCU. If the temperature is greater than 45°C the duty of the cycle is increased to 95%. If the temperature is greater than 60°C the ADP5065 automatically stops the charge process. The temperature thresholds could be fine-tuned by placing a fixed resistor in parallel or in series with the thermistor.
The battery under test is connected to the input-output board by a four-wire Kelvin connection to eliminate errors caused by the lead resistance. The I+ and I- connecting wires must have low lead resistance to carry the charging and discharging current. The V+ and V- lines sense the voltage of the battery and carry only a small bias current. The charging and discharging current is sensed by measuring the voltage across the 0.02 O, 1% current sense resistor.
All the battery information is sensed differentially to increase the robustness or reduce the common-mode error, which is very important because of the large ground currents during charging or discharging.
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How the Lipo Battery Voltage Tester Work:
The circuit uses the ADP5065 fast charging battery manager for flexible, efficient, high-stability charging control with low cost, small printed circuit board (PCB) area, and ease of use compared to traditional discrete solutions. Highly integrated precision data acquisition processing is provided by the ADuCM360 precision analog microcontroller. The ADuCM360 acquires the battery voltage, current, or temperature. A high-precision analog-to-digital converter (ADC), digital-to-analog converter (DAC), and an on-chip microcontroller allow completely self-contained control of the charging and discharging process. The analog front end is fully differential with high CMRR or excellent immunity to both common-mode and ground noise caused by large currents generated during the charge or discharge cycles.
Frequently Asked Questions
How does a LiPo battery work?
A Lipo battery is constructed from separate cells the all connected to form the specific battery. the Lipo cell has a nominal voltage of 3.7V. When connecting these in series, the voltage increases, meaning you get 7.4V for a 2-cell battery, 11.1V for a 3-cell battery, 14.8V for a 4-cell battery, etc.
How does a battery tester work?
Battery testers work by applying load and monitoring the voltage and current of the battery. The actual process is quite simple the conductive elements of the tester touch both the positive and negative contacts on the battery and the current is released and can be measured.
What is the maximum current for a LiPo battery?
Do not exceed the maximum battery voltage of 4.2V per cell (4.35V for HV batteries). Do not exceed the charging current. The basic charging current is 1C. Better Lipo batteries could be charged with a current of up to 3C and sometimes the manufacturer states a value of up to 5C.
What voltage is high-voltage LiPo?
HV LiPo. High Voltage LiPo (Lithium Polymer), would be written as LiHV. It's similar to the LiPo battery but allows you to charge it up to 4.35V per cell safely, and regular lipo can be charged up to 4.2V only.
Can I charge the LiPo battery to 100%?
Charging it fully, to 100%, stresses it a little. If you always charge to 100%, the battery will show some degradation after some 400 or 500 charge-discharge cycles. Its capacity will be reduced, and you will probably want to replace it with a new one.
