Theory of the lead-acid storage battery

2016/8/25 15:22:50

Theory of the lead-acid storage battery

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What is VRLA battery?


Reaction at positive plate (oxygen generation)
2H2O =O2 + 4H+ + 4e-

Reaction at negative plate

(chemical reaction of spongy lead with oxygen)
2Pb + O2= 2PbO

(chemical reaction of PbO with electrolyte)
2PbO + 2H2SO4=2PbSO4+ 2H2O

(Reduction of PbSO4 )
2PbSO4 + 4H+ + 4e- =2Pb + 2H2SO4

Total reaction at negative plate
O2 + 4H+ 4e-= 2H2O

Discharge characteristics
- Discharge curves
Discharge characteristics.jpg


-Deep discharge
-what is deep discharge
-deep discharges are critical for both electrodes:
   Positive
   Negative
   Dendrites
-Battery discharge current vs. discharge voltage

Discharge characteristics battery.jpg

-Cycle life in relation to depth of discharge

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After over discharged, the batteries should be recharged as soon as possible by correct ways.

-Temperature effect on battery capacity

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-Battery self discharge characteristics

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- short circuit
- impurity
- inherent reaction at negative electrode


-Shelf life
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Charge characteristics
Constant-voltage charging/Floating charging:

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2.25-2.30V/cell for standby, 2.40-2.50V/cell for cycle use with the initial current is controlled at 0.1CA

Constant current charging

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Two stage constant voltage charging
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Initial charge current ------ 0.3C.A (max.)
1st stage voltage – 2.45/cell (2.40 to 2.50 Volts /cell)
2nd stage voltage------2.28v/cell (2.25 to 2.30 volts/cell)
Switching current from---0.05C (0.04C to 0.08C.A)


Recharge stored battery

Battery age

Top charging recommendations

Within 6 months after manufacture

4 to 6 hours at constant

current of 0.1C Amps 

or 15 to 20 hours at constant

voltage of 2.40 vpc 

Within 12 months after manufacture

8 - 10 hours at constant

current of 0.1C Amps 

or 20 to 24 hours at constant

voltage of 2.40 vpc 

know more about:

Bullspower lead-acid storage battery structure