Lead Acid Battery Charger Circuit Diagram and Its Working

Charging from A.C. Supply

style="margin-top: 0in;">

The above explained methods are used on d.c. supply only. If we have a.c. supply, firstly, a.c. supply is to be converted into d.c. by means of rectifiers. Rectifiers may be half wave or full wave. In this method first voltage is stepped down by means of transformer. Low voltage a.c. supply available at the secondary of the transformer is further rectified to d.c. Rectifier may be tuner type, metallic type etc. This method of charging for a.c. supply is efficient.

(a)Trickle charging : Charging a battery at a low rate for a long time is called trickle charging. Emergency lights etc., are trickle charged. It is also used to prevent sulphatin of battery. High rate discharge Cell Tester

Ans.  This is a tester which correct terminal voltage on full load of the this tester there is one resistance of low value as load on the cell of the battery. One voltmeter i to give voltage. On the same voltmeter dial discharged conditions are also indicated by charged', 'half charged' and 'dead'. One st connected in parallel with the voltmeter to or This tester gives the reading to one cello Following precautions are to be taken while tester:

1. It should not be connected with cell ten

2. clean the two terminals of tested and cell before using.

 

What is Hydrometer?

Ans. This meter is used to test the specific gravity of the liquid. It consists of a glass-made tube with bulb glass tube is filled with small lead pieces and is fitted with scale on which specific gravity is written as well as the indication of charged to discharged condition of a celli also written. This hydrometer is kept in another glass-made

tube. On one side o the other side, nozzles of this meter is pressed and, in the electrolyte of th glass tube in which with dilute H.SO one side of this tube a rubber ball is fitted and on r side, nodal is fitted. When the ball or is pressed and released while keeping this meter lectrolyteof the cell, the electrolyte comes in the outer sbe in which Hydrometer bulb floats and gives reading Dilute H.SO,. The bulb will sink in the electrolyte while its strong H SO, the bulb will come up. Hence, it gives ding. The electrolyte is so filled that the Hydrometer should not stick on the upper head or the bottom of the outer tube.

Reading on the Hydrometer Full charge               1280

Half charge                                                                 1260

Full discharge                                                             1200

or Dead                                                                       1180

APPLICATION OF BATTERY IN INVERTER, BATTERY CHARGE & UPS

Can car batteries be charged in A.C. supply area? If not, state what equipment you propose to provide for charging batteries in such an area? What should be the specific gravity and voltage per cell of a fully charged acid type battery?

 

 

Ans. Car battery can be charged on A.C. supply by converting it into D.C. by rectifier, but it cannot be charged directly on A.C. supply because this current always change Direction and strength. Once it is (+ve) and then (-ve). When it is +ve, it charges the battery but when it is.-ve, it will discharge the battery. And this cycle changes very rapidly so the battery cannot be charged on A.C. supply.

Metal rectifier is the simplest and cheapest equipment used for converting A.C. to D.C. The connections FOR BATTERY CHARGES.

The specific gravity should be 1280 when the cell is fully charged. The voltage of the cell is 2.1 volts. Charging Lead-Acid Cells by Automatic Battery Charger

 

Lead-acid cells should not be fast or quick charged, and definitely not overcharged. Even over discharging below 1.6 V per cell should be avoided. For standby operation where mains failures are frequent, straight constant current can be used but the current should be set low - usually between C/100 and C/1000. A battery can get overcharged even at this slow rate. A multi-step charge cycle is best for lead-acid batteries. during this methodology, the battery is charged at no more than two hundredth of its rated capability till a particular voltage is reached (average two.15 V per cell). Thereafter, the charger ought to mechanically switch to a lower output voltage (about twenty three V per cell). Some advanced systems have a 3rd step - a temperature sensing and compensation since charging is quicker at elevated temperatures. when full charge, constant voltage charging ought to be removed. shows the circuit diagram of a really straightforward lead-acid battery charger. The circuit provides protection from load short-circuit and from reverse battery polarity. A BEL kind 2N3668 style of SCR is employed as a rectifier furthermore as a change component to terminate the high current charging method once battery gets totally charged.

A transformer provides low voltage A.C. offer for the rectifier. electrical device details faucets within the secondary coil beware of mains voltage variations. the element semiconductor Q1 won't conduct till the D.C. voltage on the market at the junction of R4 and also the one hundred ohms planned exceeds zero.12 V, i.e., 0.6 V for V be of zero1 and 0.6 V for element diode D2. The planned potentiometer is therefore adjusted that this happens once the battery is totally charged. 

When a discharged battery is connected to the charger, Q1 is off and also the SCR is triggered on every 0.5 positive cycle via R1 and D3. The corrected current charges the battery. because the battery gets charged, its voltage rises and once the battery is totally charged, Q1 starts conducting. This bypasses the triggering gate current of SCR Q2 via R1, D1 and Q1. The SCR will now not be triggered and also the charging method stops. However, alittle trickle charging current keeps flowing via R2 and D4. electrical device R2 sets the worth of trickle charge current. a 1 ohm high electrical power electrical device created out of Nichrome wire limits the flow of excessive charging current once the charger is connected to a very dead battery.

Part List

B1                                    twelve V Battery

D1, D3, D4                     BY a hundred twenty five

D2                                   SD50

 

R1                                     330 ohms.1/2 w

R2                                    220 ohms, 6 W

R3                                   one hundred ohms, 1/2W

R4                                   820 ohms, 1/2W

Preset one hundred ohms

Q1 B.C. 148

Q2                                  2N3668

 

What is the strategy ordinarily adopted for charging alittle variety of batteries from A.C. single section line? What ar the principal parts of charger of the on top of kind ?

Ans. Metal rectifier is usually used for charging alittle variety of batteries from A.C.

The principal parts ar as follows:

1. electrical device (stepdown).

2. transformer (tappings ar taken from the transformer).

3. Metal rectifier (full wave or 0.5 wave)

4. meter and meter.

5. D.C. and A.C. side fuse.

6. Some mounted resistance

UNINTERRUPTED POWER SUPPLY (UPS)

An uninterruptible power offer (UPS) or battery/ regulator backup, is associate electrical equipment that gives emergency power to a load once the input power supply, generally mains power, fails. A UPS differs from associate auxiliary or emergency installation or standby generator in this it provides near-instantaneous protection from input power interruptions, by supply energy hold on in batteries, supercapacitors, or flywheels. The runtime of most UPS is comparatively short, however ample to start out a standby power supply or properly finish off the protected instrumentation. A UPS is employed to guard computers, knowledge centers, {telecommunication instrumentation|telecommunication system|telecom system|telecom equipment|communication system} or different electrical equipment wherever associate surprising power distruption might cause injuries and fatalities. Batteries employed in UPS The run-time for electric battery operated UPS depends on And size of batteries and rate of discharge, and also the potency of the electrical converter. 

the entire ca could be a perform of the speed at that it's discharged? 

Manufacturers offer run-time rating in minutes for prepackaged UPS systems. Larger "Germ systems need careful diaphoresis of the load, electrical converter potency, and battery characteristics to make sure the specified endurance.

When a storage battery is charged or discharged, this at the start affects solely the reacting chemicals, that ar at the interface between the electrodes and also the solution. With time, the charge hold on within the chemicals at the interface, spreads by diffusion of those chemicals throughout the amount of the active material.

CARE AND MAINTENANCE OF CELL/BATTERY

A battery manufacturer sometimes provides the subsequent indications for brand new and traditional Battery.

Ans. initial Charge on New Battery:

1. Fill the battery with cool battery grade acid of  1200 at on top of thirty and 1260 at 30° to rock bottom of the filling hole.

2. permit to face twelve hours ar restore the acid level exploitation identical gravity acid as before; replace filler plug.

3. Charge at the five Amp current for sixty hrs, exploitation electricity

 4. If the 40° temperature is reached, suspend charge till the acid temperature is a minimum of 5°C below the limit before resuming charge.

5. finish of charge is indicated by :

(a) Voltage and relative density remaining constant for 3 serial hourly readings.

(b) Gas is freely evolved from every cell.

6. At the tip of charge regulate the precise gravity, if necessary, at 1270 to 1285 by addition of water.

7. At the tip of charge regulate the acid level to rock bottom of the filling hole.

 Normal Charge

If the gravity or the acid falls to one,100, the battery ought to be at traditional charge at the seven Amp. Current.

 Maintenance

 1. The battery should be secured firmly on the vehicle. The cables should not pull on the battery terminals.

2. continually use water to take care of the acid level at rock bottom of the filling hole. ne'er add acid.

3. Keep vent plugs tight.

4. keep the battery clean and dry, significantly the highest .

5. keep the terminal clean by coating them with pure mixture. Don’t use grease.