1. What is discharge efficiency?
Discharge efficiency refers to the ratio of the actual power released to the final voltage under certain discharge conditions and the rated capacity, mainly affected by the discharge rate, ambient temperature, internal resistance and other factors, under normal circumstances, the higher the discharge rate, the lower the discharge efficiency. The lower the temperature, the lower the discharge efficiency.
2, what is the rate discharge of the battery?
When discharging, the relationship between the discharge current (A) and the rated capacity (A•h) is expressed.
3, what is the hourly rate of battery discharge?
The number of hours required to complete the rated capacity according to a certain output current is called the discharge time rate.
4. What is the energy density of the battery?
The amount of electrical energy contained per unit volume of a battery.
5. What standard does lead acid battery use?
The battery standard is divided into three levels: national standard, industry standard and enterprise standard. The current industry standard for automotive batteries is JB/T 10262-2001.
6, how is the electric vehicle lead-acid battery named?
Automotive lead-acid battery name is called 6-DZM-X, where X is the suffix, X can be 8, 10, 12, representing the capacity of the battery. 6DZM represents 6 groups of single-cell battery packs to combine a 12V voltage electric vehicle special valve-controlled sealed maintenance-free battery, if it is a colloidal battery, its marking method is 6-DJM-X.
7, lead-acid battery capacity labeling method is what?
C2 shall prevail, that is, 0.5C2 current discharge, when the voltage reaches the battery discharge termination voltage when the product of the discharge time and current should be equal to or close to the rated capacity value. For example: a 12V, 12Ah battery, 5A current discharge, discharge termination voltage reaches 10.5V, the time can not be less than 140min; Similarly, a 12V, 10Ah battery, 5A current discharge to the voltage reaches the termination voltage of 10.5V, the time can not be less than 120min. The error is 0.1Ah
In fact, the industry standard stipulates that a 10Ah battery should discharge to the termination voltage at 5A current for no less than 120min. Enterprise products actually achieve 130~137min.
8, What is the overcharging capacity of the battery?
The industry standard stipulates that the lead-acid battery is continuously charged for 48h with 1.2A current, and the actual capacity shall not be less than 95% of the rated capacity.
9, What is the overdischarge capacity of the battery?
The industry standard stipulates that the initial discharge current of the lead-acid battery is 12A±1.2A, continuous discharge for 2.0h in a constant impedance mode, and the actual capacity shall not be less than 75%
10, what is the low-temperature storage characteristics of the battery?
Industry standards stipulate that lead-acid batteries are stored for 10h under the environmental conditions of -10 ° C ±0.1 ° C, and the actual capacity cannot be less than 70%.
11, how to evaluate the life of lead-acid batteries?
With a depth discharge of 75% capacity, the life should not be less than 350 times.
12, what are the advantages and disadvantages of lead-acid batteries?
(1) Advantages - low price: the price of lead-acid batteries is 1/4 to 1/6 of the price of other types of batteries. A single investment is relatively low and most users can afford it.
(2) Disadvantages - large weight, large volume, low energy to mass ratio, delicate, strict requirements for charge and discharge.
13, why should the battery be stored for a period of time before packaging and shipping?
Battery storage performance is an important parameter to measure the stability of battery comprehensive performance. After the battery has been stored for a certain period of time, the capacity and internal resistance of the battery are allowed to change to a certain extent. After a period of storage, the electrochemical performance of the internal components can be stabilized, and the size of the self-discharge performance of the battery can be understood in order to ensure the quality of the battery.
fourteen What is the load capacity of the battery?
When the positive and negative ends of the battery are connected to the electrical appliance, the output power that drives the electrical appliance to work is the load capacity of the battery.
15. What are the "green batteries" currently in use and research?
The new type of green battery refers to a class of high-performance, pollution-free batteries that have been put into use or are being developed in recent years. At present, the lithium-ion batteries that have been widely used, the metal hydrides nickel batteries and the mercury-free alkaline zinc-manganese batteries that are being promoted and the lithium or lithium-ion plastic batteries that are being developed, the combustion batteries, and the electrochemical energy storage supercapacitors belong to the category of new green batteries. In addition, solar cells that use solar energy for photoelectric conversion have been widely used.
16, What is the relationship between the discharge rate and the use of lead-acid batteries?
The same power of the motor, the rated voltage is different, the speed of power consumption is absolutely different. For example: the same 180W motor, when the rated voltage is 24V, the current is 7.5A; When the rated voltage is 36V, the current is only 5A, they use the same capacity of the battery pack, the combination is 36V, with 5A current discharge, the electrochemical reaction is slow, and the combination is 24V, with 7.5A current discharge, the electrochemical reaction will be relatively intense, not as easy as 5A discharge.
It is economical for batteries to discharge at a current below 0.5C. What is 0.5C? C: indicates the capacity of the battery, and C2 indicates the actual capacity determined by the battery when discharging at a 2-hour discharge rate. That is to say, when calibrated to C2 capacity, half of the capacity (0.5C2) should be released every hour to meet the capacity regulations, if more than 0.5C2, its capacity will be discounted. And it's bad for battery life.
Now, a battery with a capacity of 12Ah marked at the 2-hour discharge rate should be marked as C2=12Ah, so 0.5c2 =0.5×12=6A. Therefore, the 12Ah battery is discharged at 0.5C, which is the current of 6A. 10Ah battery, 0.5A.
The battery works for a long time, and the output working current is not greater than the rated capacity of the battery Cx /X, X is the hour rate under the rating of the battery, which is the principle of selection. If X is 2, the discharge rate should be 2 hours. If the X value is 3, the use time should be considered as 3 hours.
17, the current lead-acid battery capacity there are several labeling methods?
At present, there are several methods to mark the capacity of lead-acid batteries, such as C20, C10, C5, and C2, which indicate the actual capacity discharged at the discharge rate of 20h, 10h, 5h, and 2h, respectively. If it is the capacity at the discharge rate of 20h, the label should be C20, C20=10Ah battery, which refers to the capacity value obtained by discharging the current of C20/20 for 20h. Converted to C5, that is, to discharge 4 times the specified current of C20, the capacity is only about 7Ah, electric bicycles generally run in 1~2h large current discharge, lead-acid battery in 1~2h (C1~C2) discharge power, close to 10 times the specified current, then it can actually supply only 50% ~ 54% of the C20 discharge capacity. The battery capacity is marked as C2, that is, the capacity marked at the rate of 2h discharge. If it is not C2, the correct discharge time and capacity should be calculated. If the capacity marked with 5h discharge rate (C5) is 100%, the actual capacity is only 88% if it is changed to be discharged within 3h; Only 78% were finished within 2 hours; When it is finished in 1h, only 65% of the capacity is left when it is discharged in 5h. The capacity indicated is assumed to be 10Ah. So now with 3h discharge can only get 8.8Ah actual electricity; If it is discharged at 1h, it can only get 6.5Ah of electricity, reduce the discharge rate at will, discharge current > 0.5C2 not only the capacity is reduced than the indicated, but also has a certain impact on the life of the battery. Similarly, for a battery with a marked (rated) capacity of C3, the discharge current is C3/3, that is, ≈0.333C3, if it is C5, the discharge current should be 0.2C5, and so on.
18, what are the common characteristics of secondary batteries?
The common characteristics of the secondary battery when charging, the negative electrode produces gas, surrounds the negative electrode, so that the electrons can not reach the negative electrode for electrochemical reaction, which not only affects the charging efficiency, but also causes the plate to heat up, the electrolyte to evaporate and dry, and the concentration to change. The water evaporation of the lead-acid battery electrolyte becomes concentrated, which will promote the vulcanization of the plate, reduce the charging efficiency, reduce the capacity, and finally cause the battery to be scrapped
All batteries should not be over-discharged, over-discharge is to reduce the cost of short life, discharge is not lower than the discharge termination voltage.
19, why should the battery be fully discharged every month?
If the lead-acid battery is in a state of incomplete discharge for a long time, it should be given a chance to fully discharge once a month to maintain the activity of the battery plate material. Full discharge can run long distance until the controller undervoltage protection, automatic cutoff.
20, What are the unfavorable factors for the battery?
There are many unfavorable factors to the battery, mainly in the charge and discharge stage.
(1) The "two super" discharge stage is mainly the discharge current overvalue, that is, the discharge exceeds the allowable current value for a long time; The second problem with discharge is overdischarge, that is, exceeding the amount of discharge allowed by the battery, called "two excess", which is very harmful to the battery life.
(2) "two pass", "two owe" Charging stage has "two pass", "two owe".
a. "two passes" : one pass is overcharge; The lead-acid battery is stored for too long and does not need to be replenished regularly.
b. "two owes" : one is the lead-acid battery undercharge, the battery is often dissatisfied, and the plate can not be restored in time after vulcanization, which is extremely taboo for lead-acid batteries; The other is the underbalance between the single cell batteries in the battery pack, resulting in the gap between the degree of discharge and the degree of charging between the single cells in a group of batteries, the more undercharged, the more overcharged. Affect the life of the entire battery pack, but also to their own economic expenditure.
"Two over" and "two owed" is the enemy of the battery, can not be underestimated. But "two" and "two" is caused by people themselves, the problem is more complex, there are many reasons, from the selection, the use of maintenance, the rationality of the controller and the charger, the timely detection of the cause of battery failure, etc., they are interrelated.
