Construction of electric vehicle batteries

Electric vehicle batteries, you must meet the following conditions:

* High

* seismic. Shock

* long life

* Easy maintenance

Because glass fiber tube lead-acid batteries are made of the cumulative results of several experiments, it has a number of advantages.

1. Plate

Select the appropriate size according to battery capacity and the number plate combination. The charge and discharge, the bipolar active substances with the repeated changes in volume expansion and contraction. Polar substances, the cathode plate of spongy lead a strong binding force, while the anode of lead peroxide combination of weak, so the occasion of the charge and discharge, will slowly fall off, that is, for lead-acid battery life is limited because . Extend the use of the battery, and resistance to seismic shocks, the anode plate of the improved Serve as urgent priorities.

Glass fiber tube anode plate: This is the hose to the glass fiber system connected to the comb-shaped lead alloy grid (core K), in between the filling hose and lead powder core gold after the hose, seal, so that The change in the generation of reactive substances that, as active substances that will not fall off, and also a good contact with the electrolyte is a very good plate material. Use of batteries with this plate is the only choice of electric vehicles. Braided hose is based on 9microm (µ) of the glass fiber woven tube pocket, elastic, and can be resistant to expansion or contraction, and the penetration of the electrolyte is also very good, but the best product in this tube, a long time and practical performance is good.

Paste-type plate: dilute sulfuric acid refining the paste is to lead powder coating system in the lead alloy grid, and soon after the formation of its dry active substance. This approach has been used in lead-acid batteries in the cathode plate, and also used in the automotive, truck battery anode plate.

2. Separators

To prevent the cathode and anode short circuit between the plates, but will not hinder the flow of ions between two poles. And after prolonged use, it will not deteriorate, or release impurities. Lead-acid batteries are normally used glial isolation plate.

3. Battery Case

Strong acid, both mechanical strength. Batteries for electric vehicles using the material toughness of the shell is a special treatment is made of synthetic resin, the mechanical strength of particularly strong, site also uses the same material to melt and then.

4. Electrolyte

Electrolyte specific gravity at 20 °C, the value of the standard, the electric vehicle battery is fully charged, the electrolyte specific gravity of 1.280 standard.

5. Liquid outlet plug

Liquid discharge port plug for the charging function of the gas produced and added water, determination of specific gravity.

Battery capacity

The capacity of batteries for electric vehicles, said of the following conditions:

Electrolyte ratio 1.280/20 °C *

* current discharge current 5 hours

* discharge termination voltage 1.70V/Cell

* discharge of the electrolyte temperature 30 +/- 2 °C

1. Discharge voltage drop discharge before the discharge terminal voltage is higher than no-load voltage (open circuit voltage) is low, the following reasons:

(1) V = EI.R

V: terminal voltage (V) I: discharge current (A)

E: open circuit voltage (V) R: Internal resistance ()

(2) discharge, the electrolyte has dropped, the voltage is also reduced.

(3) discharge, the battery internal resistance that increases, when fully charged, the case of 1 times, when fully discharged, that will increase 2 to 3 times.

When the battery voltage for lifting the reason for walking than the voltage is low, is due to the lifting of the hydraulic motor running with the drive motor than power, so put current, is also on the larger type of IR .

2. The capacity of said battery

In the capacity tests, the relationship between discharge rate and capacity as follows:

5HR....1.7V/cell

3HR....1.65V/cell

1HR....1.55V/cell

Non-arrival to continue to discharge the voltage Shihai, the deeper the discharge, the battery temperature will rise, the more serious degradation of the active substance, thereby shortening battery life.

Therefore, forklifts, no load when the battery voltage if the rose has reached 1.75v/cell (24cell the 42v, 12cell the 21v), should stop using the charger immediately.

3. Battery temperature and capacity

When the battery temperature decreases, its capacity for the following reasons will be significantly reduced.

(A) electrolyte difficult to spread, polarized activity of the chemical reaction rate is slower.

(B) the electrolyte resistance increases, the battery voltage drops, the battery capacity will 5HR down with the battery temperature is reduced.

Therefore:

(1) the use of the winter than in summer time is short.

(2), particularly the use of batteries in the freezer because the discharge volume, leaving the day of the actual use of time was significantly shortened.

Ruoyu extend the use of time, then in the winter or into the freezer, they should first raise its temperature.

4. Discharge and life

Repeated charge and discharge for day use, the battery life will be because of the depth of discharge, and be affected.

5. Discharge and the proportion of

The proportion of electrolyte battery is almost proportional to the amount of discharge. Thus, according to the proportion of the battery fully discharge and 10% the proportion of discharge, you can calculate the amount of battery discharge.

Determination of electrolyte specific gravity of lead acid batteries that the best way to discharge. Therefore, the periodic determination of the proportion of after use in order to avoid excessive discharge, the measured weight, they are also the temperature of the electrolyte side to 20 degrees C the conversion out of proportion, do not make it down to 80% of the value of discharge below.

6. Discharge status and the internal impedance

Internal resistance will increase due to increased discharge, particularly when the discharge end, the maximum resistance, the main reason for the discharge current is generated within the plate makes a poor conductor of lead and sulfuric acid electrolyte 鈹€ a decline in the proportion, have led to increased internal resistance, so After discharge, be sure to immediately charge, if allowed to continue to discharge state, the lead sulfate to form stable white crystalline after (namely, the phenomenon of the literature mentioned sulfide), even if the charge, the active plate materials are not restitution, but will shorten the battery life span.

Of white lead sulfate

Battery discharge, the cathode and anode plate at the same time produce lead sulfate (PbS04), if allowed to continue to discharge, not charge, the last will form stable white lead sulfate crystals (even recharge, be difficult to resume the original active substance) This condition is called white sulfuration.

7. Discharge temperature

When the battery over-discharge, internal resistance is increased significantly, so the battery temperature will rise. Discharge when the temperatures are high, the temperature will increase the charging is completed, so the end of the discharge temperature control for the best below 40 °C.

Management Charge

1. Battery charging characteristics

The terminal voltage of the battery charge be expressed as follows

V = E + IR

E = battery voltage (V) I = charging current (A) R = internal resistance ()

2. Battery temperature and life

Battery temperature (electrolyte temperature) increases, the anode and cathode active material that the board will be degraded, and corrosion of the anode grid, and shorten the battery life, relative, battery temperature is too low, will reduce the capacity of the battery electrical storage, easy over-discharge, thereby enabling shorter battery life. This relationship also due to the battery type, plate material and have changed. Therefore, the use should be subject to the following conditions:

Usually the electrolyte battery temperature should be maintained at 15 ~ 55 °C as the ideal use of the state, a last resort, and do not exceed the discharge -15 ~ 55 °C, charging the range of 0 ~ 60 °C. Actual use, due to the temperature rise during charging, therefore, the discharge end of the electrolyte in order to maintain the temperature below 40 °C for the best.

3. Charging capacity and life

Battery charge level required for the discharge of 110 to 120%. Discharge and battery life with a close relationship, assuming the amount of charge 120% amount of discharge when the battery life for the 1200 back (4 years), then when the battery charge discharge capacity of 150% capacity when the battery life can be calculated as:

1200 x 120/150 = 960 back to back (3 * 2 years)

And 150% of this charge, forcing the water is the decomposition of gas, electrolyte suddenly reduced, will charge the end of the temperature rise, temperature rise caused by the results of life time shorter. In addition, repeated charge and discharge less than that would severely affect battery life.

* stacker weight lifting, if the battery temperature is kept between 10 ~ 40 °C, the charge level is also maintained at 110 ~ 120%, the most able to extend battery life, this time the proportion of completed charging, the conversion value of approximately 20 °C 1 * 28.

4. Gas production and ventilation

Charging the gas is a mixture of oxygen and hydrogen gas, hydrogen, explosive, if the air more than 3.8% hydrogen, and because near the fire source, it will explode. Charge must be well ventilated place, attention away from the fire, to avoid electric shock.

Fifth, the management of electrolyte

1. Determination of specific gravity

Measuring the proportion shall be used to draw the electrolyte type hydrometer slowly inhaled the outer cylinder, from the buoys to detect the proportion of the scale.

The proportion of electrolyte lead-acid batteries are changed with temperature, electrolyte specific gravity is based on the proportion of 20 degrees Celsius as the standard, so the reading on the hydrometer must be converted to 20 degrees Celsius standard weight. When the temperature changes one degree Celsius, then that changes the proportion of 0.0007, so the proportion of the measurement, we must measure the temperature, the temperature, use the rod alcohol thermometer.

The measured temperature t °C when the specific gravity of St, then the following type conversion standard temperature of 20 °C, the proportion of S20

S20=St+0.0007(t-20)

S20 ... is translated into the proportion at 20 °C

St .... as t °C measured when the proportion of

t. .... is the measured temperature of the electrolyte of the actual C

For example: 20 °C when the specific gravity of 1.280 persons, at 10 °C into 1.287; 30 °C, the becomes 1.273

2. Supplementary water

Repetitive firing, the electrolyte surface will slowly decline, so regularly review the electrolyte level, at any time to add water to maintain the appropriate level, if the issues ignored pay, and expose the plate, it will hurt the plate.

3. Impurities in the electrolyte and battery life

If the electrolyte containing nitric acid, hydrochloric acid, sulfurous acid, salt, pigment, organic, etc., will be corrosion plate to shorten the battery life, but also speed up the self-discharge, in addition, copper, nickel, iron, manganese will cause harm to the battery increased self-discharge.

Additional battery level, be sure to use the water, wash with water battery, be sure to rinse the battery cap tightly closed to prevent water flow into the battery.

4. Pay the disadvantages caused by too much

Pay in excess of the maximum when the liquid level (see Section 4-1) the overflow will occur during charging, leaving the loss of dilute sulfuric acid composition, corrosion battery box, electrical storage capacity of the electrolyte caused by the low proportion of inadequate.

Six other

1. Self-discharge

Its internal battery when the pure chemical reaction occurs, or because of pollution caused by the electrochemical reaction impurities, or both will be a long time without power, namely, as self-discharge. Degree of self-discharge of the power structure is, as the battery temperature, the proportion of impurities, such as used varies, usually in one day will release the 0.5 to 1%, the battery during storage before use will be self-discharge, consumption of storage capacity.

When the battery discharge state in the long-term sustainability, then once the form of white lead sulfate, even if the recharge, can not restore its capacity. Be sure to stock every 1 month period on a single charge.

2. Battery life of the final determination of the

To the end-of-life battery, its capacity will be reduced, as the capacity reduction in the numbers back to what extent? Determination of the Keyi capacity test.

Before discharge to determine the proportion of the battery voltage has reached the highest value, and then continued to charge 1 hour to fully charge.

The proportion of final charge is adjusted to 1.28 +/- 0.01 (20) to maintain the required liquid surface is also standard.

Discharge start time: fully charged for 1 hour.

Discharge current: 5HR size capacity 1 / 5 (5HR400AH when the fixed current 80A)

Capacity: discharge current x voltage reached before the termination of the discharge time

 

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