威达铅酸蓄电池基本构造

基本构造：

正负极板（1）
●铅酸蓄电池'>蓄电池的极板，依构造和活性物质化成方法，可分为四类：涂膏式极板、管式极板，化成式极板，半化成式极板。
●涂膏式极板（涂浆式极板）由板栅和活性物质构成的。
●板栅的作用为支撑活性物质和传导电流、使电流分布均匀。
●板栅的材料一般采用铅锑合金，免维护电池采用铅钙合金。
●正极活性物质主要成分为二氧化铅，负极活性物质主要成分为绒状铅。

隔板（2）
●电池用隔板是有微孔橡胶、颜料玻璃纤维等材料制成的，它的主要作用是：
■防止正负极板短路。
■使电解液中正负离子顺利通过。
■阻缓正负极板活性物质的脱落，防止正负极板因震动而损伤。
●因此要求隔板要有孔率高，孔径小，耐酸，不分泌有害杂质，有一定强度，在电解液中电阻小，具有化学稳定性的特点。
电解液（3）
●电解液是蓄电池'>蓄电池的重要组成部分，它的作用是传导电流和参加电化学反应。
●电解液是由浓硫酸和净化水（往离子水）配制而成的，电解液的纯度和密度对电池容量和寿命有重要影响。
●汽车用铅酸蓄电池采用电解液密度为1.280±0.005g/cm3(25℃)稀硫酸。
电池壳、盖（4）
●电池壳、盖是装正、负极板和电解液的容器，一般由塑料和橡胶材料制成。
排气栓（5）
●一般由塑料材料制成，对电池起密封作用，阻止空气进进，防止极板氧化。同时可以将充电时电池内产生的气体排出电池，避免电池产生危险。
●使用前：必须将排气栓上的盲孔用铁丝刺穿，以保证气体溢出通畅。
其它：
威达蓄电池除上述部件外，还有链条（6）、极柱（7）、鞍子（8）、液面指示器等零部件。

In the process of testing Viada lead-acid batteries, it is often encountered that the failure of Viada lead-acid batteries and abnormal data make the test can not be carried out or the test is terminated in advance. Therefore, it is very important to grasp fault analysis for detection work.

1. Fault phenomena and causes

1, the phenomenon and causes of the reverse pole

The reverse pole of the lead battery means that the positive and negative poles of the battery have changed, and the reverse pole phenomenon is reflected in two aspects, one is because a single cell battery pole group is reversed or the entire battery pole group is reversed when the lead battery is assembled. In this case, the end voltage value of the lead-acid battery is less than the sum of the rated voltage of each single battery or the end voltage is negative when the voltmeter is used to measure the end voltage. On the other hand, the lead battery is used in multiple series when the capacity is discharged, due to the low capacity of a battery (or a single battery) or the total loss of capacity. When discharging, the battery is quickly discharged and counter-charged by other batteries, so that the original negative electrode becomes positive, the original positive electrode becomes negative, and the terminal voltage appears negative.

For the former reverse pole fault, when measuring the battery terminal voltage (a battery composed of multiple single batteries), it can be found that if there is a single battery reverse pole, not only loses the 2V voltage of the battery, but also increases the 2V reverse voltage, and the end voltage should be reduced by about 4V. For example, for a battery with a rated voltage of 12 V, if the terminal voltage is measured to be about 8 V, there is a single cell battery reverse pole. If the measured terminal voltage is about 4 V, there are two single cell inverse poles, if the measured terminal voltage is about -4 V, there are four single cell inverse poles, if the measured terminal voltage is -12 V, there are six single cell all inverse poles.

For the latter type of inverse fault, the terminal voltage value (negative) varies with the discharge condition. In general, when testing, the battery should be removed from the discharge line in time for this situation, so as not to damage the battery.

2. Short-circuit phenomenon and causes

The short circuit of the lead battery refers to the connection of the positive and negative electrode groups inside the lead battery. The short-circuit phenomenon of lead battery is mainly manifested in the following aspects:

(1) The open circuit voltage is low, and the closed circuit voltage (discharge) soon reaches the termination voltage.

(2) When the large current is expelled, the terminal voltage drops rapidly to zero.

(3) When opening the circuit, the electrolyte density is very low, and the electrolyte will freeze in a low temperature environment.

(4) When charging, the voltage rises very slowly and always maintains a low value (sometimes falling to zero). (5) When charging, the electrolyte temperature rises very quickly.

(6) When charging, the electrolyte density rises very slowly or almost no change.

(7) No bubbles or gas appear very late when charging.

The main reasons for the internal short circuit of lead batteries are as follows:

(1) The quality of the partition is not good or defective, so that the plate active material passes through, resulting in positive and negative plate virtual contact or direct contact.

(2) The baffle channeling causes the positive and negative plates to be connected.

(3) The active material on the plate expands and falls off. Due to excessive deposition of the shed active material, the lower edge or side edge of the positive and negative plate is in contact with the sediment, causing the positive and negative plates to be connected.

(4) conductive objects fall into the battery to cause the positive and negative plates to be connected.

(5) The "lead current" formed by the welding pole group is not eliminated, or the "lead bean" exists between the positive and negative plates when assembled, and the positive and negative plates are connected due to the damage of the partition during the charge and discharge process.

3, plate sulfation phenomenon and causes

Plate sulfation refers to the natural white hard lead sulfate crystal on the plate, and it is very difficult to convert lead sulfate into active substances when charging. There are several main phenomena after sulfation of lead-acid battery plate.

(1) The voltage of the lead battery rises very quickly during the charging process, and the initial and final voltage is too high, and the final charging voltage can reach 2.90V/single cell or so.

(2) In the discharge process, the voltage is reduced quickly, that is, it is prematurely dropped to the termination voltage, so its capacity is significantly reduced than that of other batteries.

(3) When charging, the electrolyte temperature rises quickly and easily exceeds 45 ° C.

(4) When charging, the electrolyte density is lower than normal, and bubbles occur prematurely when charging.

(5) The color and state of the plate can be found abnormal when the battery is dissected. The positive plate is light brown (normal dark brown), the surface of the plate has white lead sulfate spots, the negative plate is gray (normal gray) the surface of the plate is rough, as if there is a feeling of sand when touched, and the plate is hard.

(6) severe sulfation, the white crystal of lead sulfate formed by the plate is coarse, and can not be restored to active substances under normal circumstances.

The main causes of plate sulfation are as follows.

(1) The initial charge of the lead battery is insufficient or the initial charge interruption time is long.

(2) The lead battery is not charged for a long time.

(3) Failure to charge in time after discharge.

(4) Frequent excessive discharge or small current deep discharge.

(5) The electrolyte density is too high or the temperature is too high, and the lead sulfate will be deeply formed and not easy to recover.

(6) Lead batteries are shelved for a long time, and are not used for a long time without regular charging.

(7) Internal short circuit local action or battery surface water caused by leakage.

(8) The electrolyte is not pure and the self-discharge is large.

(9) The internal electrolyte level of the battery is low, so that the exposed part of the plate is sulfated.

Under normal use of lead batteries, most of the active substances (Pb02 and Pb) on the positive and negative plates are transformed into small crystalline lead sulfate, and these soft small crystalline lead sulfate are evenly distributed on the porous active substances, and it is easy to contact with the electrolyte when charging and restore to the original substances PbO2 and Pb.

If in use due to the above improper use of various reasons, the active substance on the plate will gradually form the lead sulfate with coarse crystalline particles, these coarse and hard lead sulfate crystals are large in volume and poor in conductivity, which will block the pores of the active substance of the plate, hinder the penetration and diffusion of the electrolyte, increase the internal resistance of the battery, and at the same time, when charging, This coarse and hard lead sulfate is not as easily converted to PbO2, Pb as the soft and small grain lead sulfate. If it lasts too long, these coarse and hard lead sulfate will lose its reversible effect, resulting in the reduction of the effective substance of the plate, the reduction of discharge capacity, and the shortening of service life.

4, plate bending and corrosion fracture

Plate bending occurs mostly in the positive plate, and the negative plate rarely occurs, and some negative plate bending is caused by the positive plate bending too much and forcing the negative plate to bend.