When the lithium battery is assembled or the finished battery pack is stored for a long time, the voltage between the individual cells is inconsistent due to the difference of static power consumption of each circuit of the protection plate and the self- discharge rate of each single cell. During the charging process, the voltage rise speed of each cell is different, which results in the increase of the voltage difference of the battery pack. The highest voltage series of single body triggers the BMS over- voltage protection in advance, which causes the whole group of batteries to stop charging. The low voltage monomer cannot be full of electricity, and the high voltage monomer cannot discharge the power. The battery capacity is reduced and the life is reduced. Equalization is the key technology to solve the difference of cell unit. The common methods are discharge equalization and charging equilibrium. The balance has the effect of balancing voltage on the lithium battery group, so as to achieve the effect of full charge and full discharge of battery capacity, and make the battery group recover the maximum capacity and extend the service life of the battery pack.
- Discharge Equalization: also known as passive equalization, discharge equalization is to take the lowest voltage of the whole battery as the reference value, and release the excess energy in other single cells with high voltage to reduce the voltage, so as to achieve the purpose of voltage balance
- Charge equalization: also known as active equalization, in the charging process, the cell with high voltage is discharged, the voltage is pulled down, the cell with low voltage continues to charge, and the voltage continues to rise. Stop equalization until all cell voltages reach the set balance Each cell is controlled by an independent equalization circuit.
1. Control panel and description
（1） Front panel
- Machine name plate: indicate machine model and parameters.
- Airborne display screen: display the real-time data of the battery, and turn the page through the “screen display” switch to view more parameters.
- Total negative pole of battery: this terminal is connected to the total negative pole of the tested battery pack。
- Negative pole of charger: this terminal is connected to the negative pole of charger, which needs to be connected when charging equalization, but not when discharging equalization.
- Input of equalization acquisition line: connect the sampling line of the battery pack to be When the equalization current is set to 60mA or below, the battery pack can be connected through the adapter board. When the equalization current of the adapter board exceeds 60mA, there is the risk of overheating and burnout of the cable. When the current exceeds 60mA, the battery pack needs to be connected through the battery clip.
- Power button: balance system power switch, with automatic locking function, it is “on” in the locked state and “off” in the reset state。
- Start button: the system start stop switch (automatic reset), long press for more than 5 seconds, when the machine makes a “beep”, release, the machine starts normally; long press for more than 5 seconds, when the machine makes a “beep”, release, shut down, stop working。
If the machine is shut down due to abnormal power failure, it only needs a short press to start normally. When the charger is connected and the charging current is detected, the machine will start automatically.The screen needs to be opened manually by pressing “screen display”.
- Screen display button: long press for 5 seconds and then release to turn on or off the display screen, which will not affect the normal operation of the system; short press to turn over the screen and view more real-time data. After shutdown, the screen will automatically turn off after a delay of 5-8 seconds.
(2) Rear panel
Fan switch: turn on or off the cooling fan. For 2-24 series models, this switch can turn off the power supply of the whole machine.
- The 2-24 series model supports any number of cell strings in the range of 2-24 strings, which is common for ternary and lithium iron
- The detection range of battery cell voltage is 1-5V (lower than 1V and higher than 5V cannot be detected), and the comprehensive error is less than 5mv. It is suitable for all batteries with voltage in this range. It has overcharge and over discharge protection, and the voltage can be set arbitrarily in this
- The controlled equalization mode is adopted, and the equalization starts after detecting that the cell pressure difference of
the battery is greater than the set value.
- Current measurement, support charge and discharge 1-30a current Charging and discharging need another charger and discharging load.
- Coulometer function, based on the current to time integration, accurate calculation of battery residual capacity, charging capacity,
- With Bluetooth function, it supports Android / Apple system, and can set and view the information of unit voltage, voltage difference, current,
- Support screen display of battery status, data and voltage of each
- Independent temperature measurement, can set the internal overheating protection value of the
4. Wiring instructions
- Battery charging equalization wiring method
Using the battery clip wiring method: the total negative pole of the battery pack needs to be connected with two wires, one of which is connected to the “total negative pole of battery” terminal of the machine, and the cross-sectional area of the wire is at least 2.5 square mm; the other is the “total negative pole” of the battery clip (the matching battery clip already has this wire, there is no need to add another wire), which is connected to the input terminal of the machine, and the number of the corresponding machine end is 1.
The “total negative pole” of the battery clip represents the negative pole of the first string of cells of the battery pack, and the corresponding machine end number is “1”.
The “B1 +” of the battery clip represents the positive pole of the first string of cells of the battery pack, and the number of the corresponding machine end is “2”.
The “B2 +” of the battery clip represents the positive pole of the second string of cells of the battery pack, and the number of the corresponding machine end is “3”. And so on
The “B24 +” of the battery clip represents the positive pole of the 24th string monomer of the battery pack, and the corresponding machine end number is “25”.
Wiring sequence: confirm that the “power” switch on the front panel of the machine is in the off state, that is, the reset position.
① Connect the AC mains power line to the 220 V AC power supply, turn on the cooling fan switch, and confirm the normal operation of the cooling fan.
② The “total negative pole” at the machine end is connected to the total negative pole of the battery pack, and cannot pass through the protection board.
③ Insert the 12-bit battery clip cable plug into the 12-bit socket corresponding to the machine end, No. 1-12, and pay attention not to insert the wrong position.
④ Insert the 13-bit battery clip cable plug into the corresponding 13-bit socket at the machine end, No. 13-25, and pay attention not to insert the wrong position.
⑤ The “total negative pole” of the battery clip is connected to the total negative pole of the battery pack, “B1 +”, “B2 +”, “B3
+” until “B24 +” is connected to the positive pole of the first to 24 strings of monomer of the battery pack respectively.
⑥ The positive pole of the charger is connected to the total positive pole of the 24th string of the battery pack. The negative pole is connected to the “charger negative pole” at the machine end. The output voltage of the charger must be the same as the saturation voltage of the connected battery pack. For example, a 100.8v charger is used for 24 series ternary cells,
and a 87.6v charger is used for 24 series lithium iron phosphate cells.
When the number of battery strings is less than 24, the positive pole of the charger shall be connected with the total positivepole of the highest string, and the redundant battery clamp shall be left empty and not connected. Pay attention to the insulation.
A. Using universal adapter board connection method
The total negative pole of the battery pack shall be connected to the “total negative pole of the battery” terminal at the machine end separately, and the wire diameter shall be at least 2.5 mm2.
There are two rows of 2.0 mm and 2.54 mm needles on the universal adapter board. All the needles with the same number are in parallel, which corresponds to the number of the input end of the machine. Note: absolutely not wrong connection, otherwise short circuit will burn needle and wire, wrong insertion will burn!!!
Wiring sequence: confirm that the “power” self-locking switch on the machine panel is in the off state, that is, the reset position.
① Connect the power line to the 220 V AC power supply, turn on the cooling fan switch, and confirm the normal
operation of the cooling fan.
② The “total negative pole of the battery” at the machine end is connected to the total negative pole of the battery pack.
③ The 12 bit plug of the universal adapter board shall be inserted into the corresponding 12 bit socket at the machine end,
No. 1-12, and attention shall be paid not to insert the wrong position.
④ The 13 bit plug of universal adapter board shall be inserted into the corresponding 13 bit socket at the machine end, No. 13-25, and attention shall be paid not to be inserted in the wrong position.
⑤ The sampling cable of the battery pack is connected to the corresponding pin of the universal adapter board, and the total negative pole is connected with the number “1”. Note that the spacing and polarity direction of the cable should not be inserted in the opposite direction, and the cable should be inserted from the total negative pole to the total positive pole.
⑥ When using the battery pack sampling line input, the equalization current should not exceed 3a, otherwise the needle and line will be overheated and burned.
When there are two plugs in the battery detection line, the two plugs cannot be connected to the same group of pins at the same time. The plug of the second detection line should be inserted into another group of pins, which must be aligned with the number. Insert the low string first, then the high string. The serial number is from 1 to 25. Do not insert repeatedly, otherwise the needle and string will be burned.
Note: When the machine is working normally, it is strictly forbidden to plug in and out all the connecting wires. Before disconnecting the connecting wires, turn off the machine power supply and the display screen first!Otherwise, the machine may be damaged!!! The instrument wiring is many, sensitive and fragile. Every step of wiring should be carefully checked, not careless. Every step must be insulated to prevent any possibility of short circuit! (There are many careless customers burning the machine in short circuit) any consequence caused by wrong wiring and improper operation shall be borne by the user. Improper operation causing damage to the machine or unsealing without permission is not within the scope of warranty.
（1） Battery pack discharge equalization wiring method
During discharge equalization, all wiring methods and sequence are the same as that of charging equalization, so it
is not necessary to connect the charger. Fill in the items of “balanced starting control voltage” and “balanced limit voltage” for the minimum string voltage value of the battery pack, set the balanced monomer voltage difference, and click “open discharge” in the “BMS control” page to start the equalization.
4. Startup procedure
Confirm that all wiring is correct again. Press the “power” switch on the front of the machine, and the system is powered on. Press the “start” key for 5 seconds, and release after the machine sends out “beep” sound, then turn on the machine, then press the “screen display” key for 5 seconds to release, and then turn on the screen display, press the “screen display” key again to release it, and then turn the screen to view more real-time data. When the charger is connected when the machine is shut down, the machine will automatically start (excluding the screen)
5. Shutdown steps
If it is charging balance, the AC mains input of charger shall be removed first. Press the “power” key for 5 seconds, the machine will turn off after it is released after the “beep” sound. After the shutdown, the screen will automatically delay 5-8 seconds to extinguish. Finally, press the power switch to turn off the system power. It is strictly forbidden to press the “power” switch directly to force the shutdown.
6. To remove a connector
- Remove the positive connection wire of
- Remove the negative connection wire of charger (the wire on the negative terminal of charger).
- Remove the battery clamp or the line from high to
- Remove the negative connection wire of the battery pack (the wire on the negative terminal of the battery).
7. How to use the equalization system
(1) connecting equipment
App (mybms) needs to be downloaded and installed when the mobile phone is connected to the equalizer. After the machine is turned on, Bluetooth is activated. At this time, you can search and pair through the mobile phone settings >
Bluetooth page. Device name: bms-ant24c, pairing password: 1234 (password cannot be modified). After successful pairing, start the app, and enter the pairing password: 1234 when connecting for the first time. After the password is correct, the mobile phone will automatically connect and read the real-time data of the machine. When Bluetooth is disconnected, it will be displayed as “no connection”. At this time, you can click “connect device” to connect manually, or leave the “BMS control” page. When you enter again, you will try to connect automatically again. You can view the connection status through the status bar. Only when the connection is completed can the machine parameters be read or modified.
Note: after the machine is in standby, the Bluetooth power supply will be automatically turned off, and the Bluetooth cannot be connected at this time. (The default of automatic standby is 3 minutes after no current). When the machine detects the discharge or charging current, the standby will be automatically removed, and the Bluetooth will be turned on again. Before searching for Bluetooth signal, please make sure that the machine is not in standby. If it is not found at one time, please try to connect several times.
(1) BMS control
The machine defaults to 24 strings of ternary cell parameters, and the parameters are set according to the actual cell type. Ferro lithium parameters: click this item and confirm to save, then it can be set as ferro lithium cell parameters with one click. Titanium lithium parameters: click this item and confirm to save, then it can be set as titanium lithium cell parameters with one click.
Factory settings: click this item and confirm to save, you can restore to ternary cell parameters with one click.
Open charging: open the charging circuit of the battery pack, which is effective when the charger is connected normally. Turn off charging: turn off the charging circuit of the battery pack.
Turn on discharge: start the external discharge of the battery pack, and start the equalization function at the same time, provided that the cell voltage reaches the value of “balanced starting control voltage” and “balanced cell voltage difference”. Turn off discharge: turn off the external discharge of the battery pack, and turn off the equalization function at the same time when the discharge is balanced.
(2) Parameter setting
At least the following parameters should be set for the normal, efficient and safe operation of the machine
- Setting the cell type in the “BMS control” page is a very important There is a risk of setting error!!!
- Equilibrium limit voltage: in any case, when any cell voltage exceeds the set value, the cell will carry out discharge During equalization, the number in front of the battery cell changes from black to green.
- Equalizing starting control voltage: start the equalizing function when the battery voltage reaches the set
- Equalizing unit pressure difference: equalizing will be started only when the pressure difference between units is greater than the set
- Balance current size: This is the balance current coefficient, not the actual Actual equalizing current = maximum equalizing current of the machine /200 x value filled in by equalizing current size. For example, for a 10A
machine, a ternary cell is used, and the balance current is filled in 60. The calculation method is: 10A / 200×60 = 3A. When the clamp is used, the maximum can be set to 200, and the balance current of the battery can reach the maximum under the full charge state, that is 10A.When the cell voltage decreases or the lithium iron cell is used, the equalization current decreases accordingly. When the universal adapter board is used for equalization, the equalization current shall not exceed 3a, otherwise the battery detection line plug may be burnt due to overheating
- Actual number of battery strings: fill in the actual number of strings connected to the If the number of strings detected by the system is less than the set value, the machine will enter the protection state, and the charging and discharging MOS will display “balanced line dropping”.
- Battery physical capacity: fill in the nominal capacity of the battery pack, and the coulometer can work accurately only after the setting is accurate.
- Battery remaining capacity: the current remaining capacity of the battery You can estimate a setting at will. When the battery pack is fully charged, the system will automatically adjust to the set battery physical capacity. Other redundant parameters do not need to be modified, and the system default can be used. When a certain parameter of the battery pack exceeds the set value and causes protection, the system will enter the protection state and turn off the functions of charging, discharging and equalization. At this time, the setting parameters can be adjusted according to the actual needs.
Note: the parameters of charge discharge protection cannot be changed at will and should be set within the safe range.
4. Balance function
(1) Charging equalization
Charge equalization is suitable for the case of large voltage difference. The best charging current shall be 50% of the actual equilibrium current. For example, there is a set of three-way batteries, the lowest monomer voltage is 3.6V, the highest monomer voltage is 4.2V, and a balance instrument with the maximum equilibrium current of 10A is used to make the charging equalization by the battery clamp. At this time, both “balanced starting voltage” and “balanced limit voltage” are set as the intermediate value of the highest string and the lowest string, namely 3.9v, both of which are set as the middle value of the highest string and the lowest string, namely, 3.9v, both of which are all set to the middle value of the constant current can be set to 200mA (no more than 60mA when universal adapter board is used), and the actual equilibrium current is up to 10A. The charging current should be set to 5A, and the equilibrium effect is the best. The principle is simple. The voltage of the monomer under 3.9v is charged with 5A current, and the voltage will always rise. Because the battery pack is charged in series, the unit with voltage above 3.9v is charged with 5A current and discharged at 10a, which is equivalent to discharging with 5A current (10-5=5), so the voltage will always drop. Until all the single voltage reaches 3.9v, the voltage of all cores reaches the equilibrium state, and the general unit voltage difference reaches 0.005v, the balance can be completed.
After equalization, all wires should be removed in time to restore the original protection board. If it is necessary to continue charging, the “balanced starting control voltage” and “balanced limit voltage” should be increased, but should not exceed the saturation voltage of the battery.
Note: the equalization current is pulse current, which is not equal to the continuous charging current.
(2) Discharge equalization
The battery pack shall be fully charged with the original protection board, the charger and protection board shall be removed, and all connecting wires shall be connected according to the discharge equalization wiring method described above, “Balanced cell voltage difference” is filled in 0.002-0.005v (according to personal requirements). When the battery clamp is used for connection, “balanced current” can be filled in 200mA, and “balanced starting control voltage” and “balanced limit voltage” are filled in for the lowest cell voltage value of the string to start equalization. At this time, the machine will take the filled value as the standard, and the monomer whose voltage is higher than the filled value will carry out discharge equalization until all the monomer voltages reach the set voltage value. During discharge equalization, click “close discharge” in “BMS control” page to manually close equalization, and click “open discharge” to restore equalization.
Whether it is charge equalization or discharge equalization, the current circuit cannot pass through the protection board, otherwise it cannot be used normally.