ppt on battery testing

8/13/2019 PPT on Battery Testing

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MTEKPRO Technologies Pvt. Ltd, New Delhi.

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Voltage Measurement

Impedance Measurement

Sulfation MeasurementDryout

Physical Inspection



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Our Technology

CEL Scan (Chemical Electrical Layer Scanning)

This Technology Brief reviews the basis andcapabilities of CEL Scan (Chemical Electrical LayerScanning) technology for assessing the health oflead acid and other batteries.

CECRI ( Central Electrochemical ResearchInstitute), Karaikudi is successfully using thisinstrument from last two years.



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As implied by the name, Chemical ElectricalLayer Scanning (CELScan) technology providesthe capability of monitoring changes in bothelectrical and chemical characteristics of lead

acid batteries. This capability permits theidentification of incipient sulfation and/ordryout processes even when single-pointmeasurements (e.g., conductance orresistance) register no appreciable deviationfrom nominal values.



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Voltage Measurement

We will Check voltage using EC2000. Readings fora charged, should be 12.8v (if per plate battery is2.12 volts) or higher after the battery is chargedand sits for at least 1 - 2 hours. If less, it needs anadditional charge.



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Even a partial discharge will cause sulfationon the plates that reduces battery capacity

and leads to premature battery failure.

Do not leave batteries dischargedDamage can occur in a very short period.



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Impedance Measurement

Impedance measurements can be performed

by passing a current of known frequency andamplitude through the battery and measuringthe resultant ac voltage drop across eachcell/unit.



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High impedance is another term for "high internalresistance". This means with age or poormaintenance, a rechargeable battery develops ahigh internal resistance causing the battery to

collapse with heavy current demands. So, whilethe battery may show a 'full charge' on a voltmeter and an acceptable capacity level on ananalyzer, when put to the test the battery is notable to sustain the current draw for theapplication causing a low battery indicator.

Lower the Impedance, Lower the chance ofBLACKOUTMTEKPRO Technologies Pvt. Ltd, New Delhi.


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The lead sulfate that forms on each plate of alead-acid battery during discharge starts out asmicroscopic crystals that are easily convertedback to active material during recharge. Over

time, however, the smallest crystals tend toshrink and larger ones tend to grow. Leftuntended, the lead sulfate crystals eventuallybecome so large that no amount of DC charging

(even at elevated voltage) can reverse theprocess. At that point, the battery will not acceptcharge and is said to be sulfated.



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Experience shows that sulfation can develop onthe plates of a lead acid battery when it is:

Left for more than a few hours at a low stateof charge state;

Allowed to self-discharge for long periodsafter charging;

Consistently undercharged; Operated at elevated temperatures; Consistently overcharged; Subjected to excessive AC ripple;



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The lead sulfate that forms on each plate of alead-acid battery during discharge starts out asmicroscopic crystals that are easily convertedback to active material during recharge. However,left untended, the lead sulfate crystals can grow,eventually becoming so large that no amount ofDC charging (even at elevated voltage) canreverse the process. The battery will no longeraccept charge and is said to be sulfated.Applying a patented 3-Stage charging regimeDynapulse technology overcomes the problemof sulfation quickly, economically and safely.



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Once sulfation has begun, the process tends toprogressively worsen any irregularities in thedistribution of charging and discharging currents withinthe plates. Furthermore, sulfation of just one cell in astring can degrade the performance, capacity, and

ultimately the life of every other cell in the string. Thedegradation occurs because the increased resistanceand reduced capacity of a sulfated cell leads to unevenstates of charge among the other cells, promotingsulfation in undercharged cells and multiple failuremodes in overcharged cells.

So when you know Sulfation level of your battery , It iseasier to judge the battery condition.



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While detailed aspects of Dynapulse batteryconditioning technology remain proprietary, theyinvolve the patented 3-stage regime outlined inTable . Current and voltage values given in the

table are typical for a 12 Volt,~100Ah lead-acidbattery. For other battery ratings, the values wouldbe scaled appropriately.

Table 1. Three-stage desulfation regime



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An important failure mode observed in valve

regulated lead acid (VRLA) batteries, is"dryout" - the progressive loss of water fromthe electrolyte.



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When properly managed, VRLA batteries retainadequate water throughout their design lives.However, when subjected to prolongedovercharging, overheating, or when a valvemalfunctions, water loss from VRLA cells can

appreciably lower the separator conductivity.Dryout of an AGM (Absorbed Glass Mat)separator causes it to shrink away from theelectrodes, ultimately producing a large increasein internal resistance and a sudden loss in

capacity. Similarly, water loss from a gelseparator can lead to disintegration of theseparator and a corresponding drop in capacity.



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Exacerbating the problem of dryout is a feedbackeffect whereby each increment of water lossincreases both ohmic heating and (during charge)

the oxygen recycle current. The increased heatgeneration further accelerates water loss,ultimately leading to a catastrophic failureprocess known as thermal runaway.

Hence, early detection of this failure mode willnot only extend battery life, it may also avert amajor accident.MTEKPRO Technologies Pvt. Ltd, New Delhi.


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Physical Inspection

That means:- Check electrolyte level.

Keep the top free of grime.

Check cables, clamps and case for obvious damage

or loose connections.

Clean terminals and connectors as necessary. Make sure exhaust tube is free of kinks or clogs.

Replace caps, finger tighten only.MTEKPRO Technologies Pvt. Ltd, New Delhi.


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Deep discharge or prolonged discharge leadsto harmful sulfation.

A discharged battery freezes much fasterthan a charged battery.

Charging can reverse discharging.

Charging gives off hydrogen and oxygen,which are explosive.



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NOT NECESSARILYA borderline battery may start the engine, butfail shortly after.



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For Further clarification please contact MTEKPROTechnologies Pvt. Ltd, New Delhi.

www.mtekpro.com

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