A lithium battery protection board is the charge and discharge protection for a series lithium battery pack; it can ensure that the voltage difference between every single cell is less than the set value (generally ±20mV) when it is fully charged to realize the equal charging of every single cell in the battery pack, which effectively improves the charging effect in the series charging mode. It also detects the over-voltage, under-voltage, over-current, short-circuits, and over-temperature status of every single cell in the battery pack to protect and extend the battery life. Under-voltage protection enables every single cell to avoid battery damage due to over-discharge when discharged for use. These are the common initiatives of global lithium battery manufacturers committed to lithium battery safety.

The board has no display, low output voltage, and can not take the load

Such bad first exclude the core bad (the core originally had no voltage or low voltage), if the core is bad should test the protection board the power consumption, to see if the protection board since the power consumption is too large resulting in a low voltage core. If the core voltage is normal, it is due to the entire circuit of the protection board not working (component soldering, false welding, FUSE bad, PCB board internal circuit not working, over the hole not working, MOS, IC damage, etc.). Specific analysis steps are as follows.

With a multimeter black pen connected to the negative terminal of the core, the red pen in turn connected to the FUSE, R1 resistor terminals, IC Vdd, Dout, Cout terminal, and P + terminal (assuming that the core voltage is 3.8V), segment by segment analysis, these test points should be 3.8 V. If not, this segment of the circuit has problems.

1. FUSE voltage changes at both ends: test, whether FUSE is on if one is the PCB board's internal circuits, does not work; if not on then FUSE has a problem (bad material, overcurrent damage (MOS or IC control failure), material problems (in MOS or IC action before FUSE is burned), and then short FUSE with wire, continue to analyze back.
2. The voltage across the R1 resistor has changed: test the R1 resistance value, if the resistance value is abnormal, it may be a false solder, the resistor itself is broken. If the resistance value is not abnormal, it may be a problem with the IC internal resistance.
3. IC test end voltage change: Vdd end and R1 resistor connected. dout, Cout end abnormal, it is due to IC solder or damage.
4. If there is no change in the voltage in front of test B- to P + between the voltage is abnormal, it is due to the protection board positive over the hole does not work.

Multimeter red pen connected to the positive pole of the core, after activating the MOS tube, the black pen in turn connected to the MOS tube 2, 3 feet, 6, 7 feet, P- terminal.

1. MOS tube 2, 3 feet, 6, 7 feet voltage change, it means MOS tube abnormal.
2. If the MOS tube voltage does not change, the P-terminus voltage is abnormal, it is due to the protection board negative over the hole does not work.

The Software Protect Lithium Battery Board short-circuit without protection

VM terminal resistance problem: a multimeter can be connected to the IC2 pin, a pin connected to the VM terminal resistance MOS tube pin, confirm the size of its resistance value. Look at the resistor and IC, MOS pins have no false solder. 2.

IC, MOS abnormal: because the over-release protection and over-current, short-circuit protection share a MOS tube, if the short-circuit abnormality is due to MOS problems, the board should be no over-release protection function.

The above is the normal condition of the bad, may also appear IC and MOS configuration caused by poor short-circuit abnormalities. As in the case of BK-901, the delay time within the IC model '312D' is too long, resulting in the MOS or other components being damaged before the IC makes the corresponding action control. Note: Among them, the easiest and most direct way to determine whether the IC or MOS is abnormal is to replace the suspected components.

The Software Protect Lithium Battery Board short-circuits protection without self-recovery.

The IC used in the design originally did not have a self-recovery function, such as G2J, G2Z, etc..

The instrument set short-circuit recovery time is too short, or short-circuit test is not removed from the load, such as using a multimeter voltage file for short-circuit pen shorting after the pen is not removed from the test end (multimeter equivalent to a few megabytes of load).

P +, P - between the leakage, such as the existence of impurities between the pads with impurities of rosin, with impurities of yellow glue or P +, P - between the capacitance is broken, IC Vdd to Vss between the breakdown. (Resistance value of only a few K to a few hundred K).

If the above is no problem, the IC may be broken, you can test the resistance value between the IC pins.

The Software Protect Lithium Battery Board's internal resistance is large

Because MOS internal resistance is relatively stable, there is a large internal resistance, the first suspect should be FUSE or PTC this internal resistance is relatively easy to change the components.

If the FUSE or PTC resistance value is normal, depending on the structure of the protection board to detect P +, P - pads, and components between the face of the hole resistance value, maybe over the hole micro-break phenomenon, the resistance value is larger.

If the above is more than no problem, we must suspect whether MOS anomalies: first determine whether there is a problem with welding; secondly, look at the thickness of the board (whether it is easy to bend), because the bending may lead to pin welding abnormalities; then MOS tube into the microscope to observe whether the rupture; finally, use a multimeter to test the MOS pin resistance to see whether it is broken.

Software Protect Lithium Battery Board ID abnormalities

ID resistor itself is abnormal due to deficient soldering, fracture or because the resistor material is not up to par: you can re-solder the two ends of the resistor, if the ID is normal after re-soldering, it is resistor deficient soldering, if fracture, the resistor will be cracked from it after re-soldering.

ID through-hole is not conductive: use a multimeter to test both ends of the through-hole.

Internal circuit problems: can scrape open the solder resist paint to see if the internal circuit is broken, short circuit phenomenon.

What is the solution?

GT-AutoLion is a lithium battery performance analysis software developed by Gamma Technologies, LLC, USA. This software can effectively predict the discharge rate characteristics, discharge temperature characteristics, current-voltage characteristics, capacity degradation and other relevant characteristics of Li-ion batteries by simply running on a laptop.

Currently, GT-Autolion provides two modules for battery simulation.

GT-AutoLion-1D

Provides a virtual battery lab that contains a stand-alone application to build a 1D analysis with all necessary functions.

• Enables the development and optimization of lithium batteries in a relatively short period of time.
• Modeling of commercial batteries under extreme conditions.
• Prediction of lithium battery degradation, lifetime, etc..

GT-AutoLion-3D

• Carving 3D distribution information of temperature, current, heat release, aging, SOC, etc.
• Fast calculation speed for system simulation and evaluation of thermal management strategies.
• Heat transfer using finite element solution (support for anisotropy, ability to couple with fluids, support for complex geometry modeling).

About Gamma Technologies

Gamma Technologies, LLC. evolves and licenses GT-SUITE, a leading multi-physics CAE system ruse software. GT-SUITE includes a complete library of physics-based modeling templates covering smooth flow, thermal systems, mechanics, electrics, magnetics, chemistry, and settings. It supports the complete development cycle coming from concept to affirmation thanks to its modular architecture, adjustable model fidelity in addition to open interface.

GT-SUITE applications include a new wide array of engineering systems like conventional in addition to hybrid vehicles, powerhouses, and drivelines, machines, motors, compressors, factors, chemistry, acoustics, air conditioning, thermal management, HVAC, hydraulics, fuel methods, and lubrication, mechanical methods, etc.

About EC Power

Based in State College, Pennsylvania, EC Power invents and develops a new paradigm of high-power, high-energy, long-lasting, fast charging, and safe batteries for vehicle electrification, renewable energy storage, and consumer electronics. EC Power is the inventor of the All-Climate Battery (ACB) technology (self-heating cell concept), which has received wide interest from and has been licensed to vehicle OEMs and battery manufacturers globally. EC Power maintains a battery prototyping factory in Philipsburg, PA for innovative product development.