How to deal with the voltage imbalance of the vehicle polymer lithium battery pack
In just a few years, the scale of its use has now expanded from our daily life to the industrial scope, it is not only used in some digital products similar to laptop computers, portable CDS, but also widely used in electric bicycles, electric vehicles, drones and other fields, the scale of use of lithium polymer battery packs is becoming more and more extensive. But how to deal with the uneven voltage of the polymer lithium battery pack?
Automotive polymer lithium battery pack voltage imbalance treatment method:
1, remove the protection plate of the lithium-ion battery, because to repair the unbalanced lithium-ion battery, we must first check the status of the lithium-ion battery and find the battery that affects the normal operation of the entire battery pack. Need to bypass the battery protection board, directly measure a single lithium battery cell, and record;
2. Charge the problematic battery separately, or test the capacity separately to check whether the capacity and internal resistance of the battery are different from that of the entire battery pack. If the difference is small, you can charge the battery separately. If the difference in capacity and internal resistance already exists, it can only be replaced.
3. Before reassembling the battery pack repaired after replenishment or replacement of monomer, the capacity should be divided to check whether the capacity meets the design requirements;
4. Recycle the battery according to the original line, install the battery protection board and outer packaging;
Note: It is important to note that lithium-ion battery packs usually have an imbalance after a period of use, so the internal resistance of the entire battery pack will be different from that of the new battery. Special treatment should be taken when replacing the monomer, and the direct replacement of the new monomer may soon repeat the problem.
1. First charge the entire lithium-ion battery pack, and float charge within 2-3 hours after turning on the light. If the battery is not powered for a long time, it can be charged normally on the protection board for 10 minutes (socket charging), and then charged normally.
2, pull out the circuit and plug of the protection board, and then make a mark. The two wires on the board cannot be recovered. Measure the voltage of adjacent pins on the line. For 48V, there are 16 voltages, 60V is 20 voltages. The first negative voltage is the voltage at which the battery becomes negative from the first row. Find a single string with a voltage below 3.50V, determine the positive and negative values, determine the negative values and make a mark.
3, use 4.2V charger to 3.50V to 3.60V to 3.70V to charge a single line, but someone has to prevent used lithium-ion batteries from being overcharged.
4. Plug the cables back in the original order, do not reverse, and put the battery into use. If you continue to use lithium-ion battery packs, the capacity of lithium-ion batteries will naturally decrease. This is related to the material characteristics of lithium-ion batteries, and also related to the material characteristics of lithium-ion batteries. The simple understanding is that the activity of lithium-ion batteries continues to decline until the final capacity is completely reduced.
5, in order to extend the service life of the lithium-ion battery pack, it is usually recommended to use a shallow charge and shallow discharge mode of lithium-ion batteries, or to charge in the case of too many lithium-ion batteries are not used or insufficient power. Lithium-ion battery life is not ideal.
The essence of the attenuation of lithium ion battery pack capacity reduction is the reduction of lithium ion content, mainly due to structural material failure or positive and negative material inactivation, electrolyte degradation, lithium ion battery abuse and other reasons. In order to extend the life of lithium-ion batteries, they must be used correctly.
