Battery FAQ's

The word “battery” comes from the Old French word baterie, meaning “action of beating,” relating to a group of cannons in battle. In the endeavour to find an energy storage device, scientists in the 1700s adopted the term “battery” to represent multiple electrochemical cells connected together.

One of the most remarkable and novel discoveries in the last 400 years was electricity. We might ask, “Has electricity been around that long?” The answer is yes and perhaps much longer. Its practical use has only been at our disposal since the mid to late 1800s, and in a limited way at first. Some of the earliest public works gaining attention were streets lights in Berlin in 1882, lighting up the Chicago World’s Fair in 1893 with 250,000 light bulbs, and illuminating a bridge over the river Seine during the Paris 1900 World Fair.

Battery failures are in part influenced by driving habits, the liberal use of auxiliary loads, hot climate conditions, start-stop and battery mount. Sometimes a battery failure can be caused by the build-up of conductive materials across the battery posts that induce an ionic discharge. Always keep the battery top and posts clean. This also applies to storing batteries.

Even under the best conditions, a quality battery ages and this manifests itself in a gradual drop of capacity. Common failures of starter batteries include:

Heat Failure Heat promotes corrosion that reflects in rising internal resistance, resulting in laboured cranking. Batteries installed in engine compartments and driving in hot climates result in higher heat failures than those operating in temperate climates. A heat failed battery can be identified with a CCA tester.

Low charge Idling and driving in gridlock with auxiliary loads engaged does not produce sufficient charge and the battery may dwell at 70% state-of-charge (SoC), a level that induces sulphation. A prolonged low-charge condition makes the battery inoperative but this condition can often be improved with long-distance driving or external charging.

Capacity fade Auxiliary loads such as heating elements and mechanical gates hasten capacity fade. The capacity loss goes unnoticed until the battery stops cranking for lack of energy. Replace the battery when the capacity drops to 40%. A CCA test cannot detect a battery with low capacity.

Factory defect Factory defects are roughly 7% or less. Improved manufacturing practises have decreased factory defects while stress related faults are increasing.

What does CCA, RC (Ah) and SoC mean?

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Figure 1: Graphic presentation of CCA, capacity and SoC.

Capacity loss that occurs naturally with usage is illustrated as a build-up of rocks. Capacity and CCA do not correlate. Source: Cadex Electronics

The most common specification of a starter battery is CCA representing cold cranking amps. Batteries also specify capacity, the electrical storage capability that is marked in ampere-hours (Ah) or Reserve Capacity (RC) in minutes. Europe uses Ah while North America goes for RC.

CCA Cold cranking amps is responsible for cranking the engine, a reading that correlates to internal battery resistance. Figure 1 illustrates CCA in the form of a free-flowing tap pouring liquid.

Capacity Represents energy storage measured Ah or RC. Figure 1 shows capacity as liquid storage. Capacity loss is shown as rock buildup that reduces volume

SoC State-of-charge is demonstrated with liquid levels that can be replenished if low.

What goes wrong?

Figure 2 illustrates a battery with low CCA that is dying after 1–2 years because of heat failure. A typical cause is corrosion that raises the internal battery resistance and lowers the CCA. The capacity remains steady but it cannot be delivered due to low CCA. Replace a battery when CCA drops to 50%.

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Figure 2: Heat failed battery.

Symptoms: Poor cranking due to high internal resistance. Failure mode is gradual and gives early warning.
Test Method: AC conductance or impedance reader. Replace battery when CCA drops to 50%.Source: Cadex Electronics

Figure 3 shows the natural decrease of CCA and capacity on a well maintained battery. The pack will eventually fail at a ripe old age due to low capacity while CCA is still in working range. A ‘no-start’ occurs when the capacity drops below a required capacity level to crank the engine. A starter battery should be replaced when the capacity drops to 40 percent.

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Figure 3. Full 4–5 year life.

Symptoms: Capacity fade goes unnoticed and the failure appears sudden. Check capacity as part of preventative service.
Test Method: Rapid-test with Spectro™. Full discharge with load bank is not recommended. Source: Cadex Electronics

A starter battery must have low internal resistance and sufficient capacity to enable cranking. CCA and capacity can be presented on a two-dimensional table by plotting CCA on the vertical and capacity on the horizontal axis. Figure 4 demonstrates three batteries in various conditions.

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Figure 4: Battery evaluation based on CCA and Capacity.

A starter battery can fail by heat failure or capacities fade. Both faults are permanent and cannot be reversed. CCA relates to internal resistance that is easy to measure; capacity reflects energy storage that is more complex to estimate.

  • Battery 1: Delivers good capacity and has high CCA. This battery performs well.
  • Battery 2: No cranking due to low capacity. A CCA check may pass this battery in error.
  • Battery 3: Slow cranking due to heat failure. A CCA check correctly identifies this battery.

Capacity, the Leading Health Indicator

A battery tester should examine CCA and capacity. CCA and capacity do not correlate. Each reading is unique, of which capacity is the more complex to estimate.

To study failure modes, a German luxury car maker tested 175 starter batteries. Figure 5 plots capacity and CCA of this extensive test that lasted six-months. Heat failed batteries were excluded.

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Figure 5: Capacity and CCA of 175 aging starter batteries.

Most batteries pass through the Capacity Line; few fail because of low CCA. The test batteries were trunk mounted and driven in a moderate climate.

Note: Test was done by a German luxury car manufacturer. Heat damaged batteries were excluded.
Test Method: Capacity and CCA were tested according to DIN and IEC standards.

As the graph illustrates, most batteries pass through the Capacity Line on the left of the green field. Very few fail by dropping through the CCA Line. Without ability to estimate capacity, batteries with high CCA pass as good, only to fail on the road because of low capacity. Meanwhile, good batteries are being replaced in error. CCA alone cannot predict the end of battery life. CCA tends to stay high while the capacity drops predictably. The Figure 6 illustrates this phenomenon on 20 aging batteries.

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Figure 6: Comparing CCA and capacity of 20 aging batteries.

Starter batteries cannot be tested by CCA alone as the reading of a normally aging battery tends to stay high while capacity drops predictably with age.

Explore SoC measurements and why they are not accurate.

Voltage Method

Measuring state-of-charge by voltage is simple, but it can be inaccurate because cell materials and temperature affect the voltage. The most blatant error of the voltage-based SoC occurs when disturbing a battery with a charge or discharge. The resulting agitation distorts the voltage and it no longer represents a correct SoC reference. To get accurate readings, the battery needs to rest in the open circuit state for at least four hours; battery manufacturers recommend 24 hours for lead acid. This makes the voltage-based SoC method impractical for a battery in active duty. Each battery chemistry delivers its own unique discharge signature. While voltage-based SoC works reasonably well for a lead acid battery that has rested, the flat discharge curve of nickel- and lithium-based batteries renders the voltage method impracticable.

The discharge voltage curves of Li-manganese, Li-phosphate and NMC are very flat, and 80 percent of the stored energy remains in the flat voltage profile. While this characteristic is desirable as an energy source, it presents a challenge for voltage-based fuel gauging as it only indicates full charge and low charge; the important middle section cannot be estimated accurately. Figure 1 reveals the flat voltage profile of Li-phosphate (LiFePO) batteries.

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Figure 1: Discharge voltage of lithium iron phosphate.

Li-phosphate has a very flat discharge profile, making voltage estimations for SoC estimation difficult.

Lead acid comes with different plate compositions that must be considered when measuring SoC by voltage. Calcium, an additive that makes the battery maintenance-free, raises the voltage by 5–8 percent. In addition, heat raises the voltage while cold causes a decrease. Surface charge further fools SoC estimations by showing an elevated voltage immediately after charge; a brief discharge before measurement counteracts the error. Finally, AGM batteries produce a slightly higher voltage than the flooded equivalent.

When measuring SoC by open circuit voltage (OCV), the battery voltage must be “floating” with no load attached. This is not the case with modern vehicles. Parasitic loads for housekeeping functions puts the battery into a quasi-closed circuit voltage (CCV) condition.

In spite of inaccuracies, most SoC measurements rely in part or completely on voltage because of simplicity. Voltage-based SoC is popular in wheelchairs, scooters and golf cars. Some innovative BMS (battery management systems) use the rest periods to adjust the SoC readings as part of a “learn” function. Figure 2 illustrates the voltage band of a 12V lead acid mono block from fully discharged to full charged.

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Figure 2: Voltage band of a 12V lead acid mono block from fully discharged to fully charged


The hydrometer offers an alternative to measuring SoC of flooded lead acid batteries. Here is how it works: When the lead acid battery accepts charge, the sulphuric acid gets heavier, causing the specific gravity (SG) to increase. As the SoC decreases through discharge, the sulphuric acid removes itself from the electrolyte and binds to the plate, forming lead sulphate. The density of the electrolyte becomes lighter and more water-like, and the specific gravity gets lower. Table 2 provides the BCI readings of starter batteries.

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Table 2: BCI standard for SoC estimation of a starter battery with antimony

Readings are taken at 26°C (78°F) after a 24h rest.

While BCI (Battery Council International) specifies the specific gravity of a fully charged starter battery at 1.265, battery manufacturers may go for 1.280 and higher. Increasing the specific gravity will move the SoC readings upwards on the look-up table. A higher SG will improve battery performance but shorten battery life because of increased corrosion activity.

Besides charge level and acid density, a low fluid level will also change the SG. When water evaporates, the SG reading rises because of higher concentration. The battery can also be overfilled, which lowers the number. When adding water, allow time for mixing before taking the SG measurement.

Specific gravity varies with battery applications. Deep-cycle batteries use a dense electrolyte with an SG of up to 1.330 to get maximum specific energy; aviation batteries have an SG of about 1.285; traction batteries for forklifts are typically at 1.280; starter batteries come in at 1.265; and stationary batteries have a low specific gravity of 1.225. This reduces corrosion and prolongs life but it decreases the specific energy, or capacity.

Nothing in the battery world is absolute. The specific gravity of fully charged deep-cycle batteries of the same model can range from 1.270 to 1.305; fully discharged, these batteries may vary between 1.097 and 1.201. Temperature is another variable that alters the specific gravity reading. The colder the temperature drops, the higher (more dense) the SG value becomes. Table 3 illustrates the SG gravity of a deep-cycle battery at various temperatures.

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Table 3: Relationship of specific gravity and temperature of deep-cycle battery.

Colder temperatures provide higher specific gravity readings.

Inaccuracies in SG readings can also occur if the battery has stratified, meaning the concentration is light on top and heavy on the bottom. High acid concentration artificially raises the open circuit voltage, which can fool SoC estimations through false SG and voltage indication. The electrolyte needs to stabilize after charge and discharge before taking the SG reading.

Learn how to charge a battery without a designated charger.

Batteries can be charged manually with a power supply featuring user-adjustable voltage and current limiting. I stress manual because charging needs the know-how and can never be left unattended; charge termination is not automated. Because of difficulties in detecting full charge with nickel-based batteries, I recommend charging only lead and lithium-based batteries manually.

Lead Acid

Before connecting the battery, calculate the charge voltage according to the number of cells in series, and then set the desired voltage and current limit. To charge a 12-volt lead acid battery (six cells) to a voltage limit of 2.40V, set the voltage to 14.40V (6 x 2.40). Select the charge current according to battery size. For lead acid, this is between 10 and 30 percent of the rated capacity. A 10Ah battery at 30 percent charges at about 3A; the percentage can be lower. An 80Ah starter battery may charge at 8A. (A 10 percent charge rate is equal to 0.1C.)

Observe the battery temperature, voltage and current during charge. Charge only at ambient temperatures in a well-ventilated room once the battery is fully charged and the current has dropped to 3 percent of the rated Ah, the charge is completed. Disconnect the charge. Also disconnect the charge after 16–24 hours if the current has bottomed out and cannot go lower; high self-discharge (soft electrical short) can prevent the battery from reaching the low saturation level. If you need float charge for operational readiness, lower the charge voltage to about 2.25V/cell.

You can also use the power supply to equalize a lead acid battery by setting the charge voltage 10 percent higher than recommended. The time in overcharge is critical and must be carefully observed. See WHAT IS EQUALIZING CHARGE

A power supply can also reverse sulfation. Set the charge voltage above the recommended level, adjust the current limiting to the lowest practical value and observe the battery voltage. A totally sulfated lead acid may draw very little current at first and as the sulfation layer dissolves, the current will gradually increase. Elevating the temperature and placing the battery on an ultrasound vibrator may also help in the process. If the battery does not accept a charge after 24 hours, restoration is unlikely.


Lithium-ion charges similarly to lead acid and you can also use the power supply but exercise extra caution. Check the full charge voltage, which is commonly 4.20V/cell, and set the threshold accordingly. Make certain that none of the cells connected in series exceeds this voltage. (The protection circuit in a commercial pack does this.) Full charge is reached when the cell(s) reach 4.20V/cell voltage and the current drops to 3 percent of the rated current, or has bottomed out and cannot go down further. Once fully charged, disconnect the battery. Never allow a cell to dwell at 4.20V for more than a few hours

Please note that not all Li-ion batteries charge to the voltage threshold of 4.20V/cell. Lithium iron phosphate typically charges to the cut-off voltage of 3.65V/cell and lithium-titanate to 2.85V/cell. Some Energy Cells may accept 4.30V/cell and higher. It is important to observe these voltage limits.

Know how to apply an equalize charge and not damage the battery.

Stationary batteries are almost exclusively lead acid and some maintenance is required, one of which is equalizing charge. Applying a periodic equalizing charge brings all cells to similar levels by increasing the voltage to 2.50V/cell, or 10 percent higher than the recommended charge voltage

An equalizing charge is nothing more than a deliberate overcharge to remove sulphate crystals that build up on the plates over time. Left unchecked, sulphation can reduce the overall capacity of the battery and render the battery unserviceable in extreme cases. An equalizing charge also reverses acid stratification, a condition where acid concentration is greater at the bottom of the battery than at the top.

Experts recommend equalizing services once a month to once or twice a year. A better method is to apply a fully saturated charge and then compare the specific gravity readings (SG) on the individual cells of a flooded lead acid battery with a hydrometer. Only apply equalization if the SG difference between the cells is 0.030.

During equalizing charge, check the changes in the SG reading every hour and disconnect the charge when the gravity no longer rises. This is the time when no further improvement is possible and a continued charge would have a negative effect on the battery.

The battery must be kept cool and under close observation for unusual heat rise and excessive venting. Some venting is normal and the hydrogen emitted is highly flammable. The battery room must have good ventilation as the hydrogen gas becomes explosive at a concentration of 4 percent.

Equalizing VRLA and other sealed batteries involves guesswork. Observing the differences in cell voltage does not give a conclusive solution and good judgment plays a pivotal role when estimating the frequency and duration of the service. Some manufacturers recommend monthly equalizations for 2–16 hours. Most VRLAs vent at 34kPa (5psi), and repeated venting leads to the depletion of the electrolyte, which can lead to a dry-out condition.

Not all chargers feature equalizing charge. If not available, the service should be performed with a dedicated device.

Lead acid batteries are sluggish and cannot convert lead sulphate to lead and lead dioxide quickly during charge. This delayed action causes most of the charge activities to occur on the plate surfaces, resulting in an elevated state-of-charge (SoC) on the outside.

A battery with surface charge has a slightly elevated voltage and gives a false voltage-based SoC reading. To normalize the condition, switch on electrical loads to remove about 1 percent of the battery’s capacity or allow the battery to rest for a few hours. Turning on the headlights for a few minutes will do this. Surface charge is not a battery defect but a reversible condition.

  • Allow a fully saturated charge of 14–16 hours. Charge in a well-ventilated area.
  • Always keep lead acid charged. Avoid storage below 2.07V/cell or at a specific gravity level below 1.190.
  • Avoid deep discharges. The deeper the discharge, the shorter the battery life will be. A brief charge on a 1–2 hour break during heavy use prolongs battery life.
  • Never allow the electrolyte to drop below the tops of the plates. Exposed plates sulfate and become inactive. When low, add only enough water to cover the exposed plates before charging. Always fill to the correct level after charge.
  • Never add acid. This would raise the specific gravity too high and cause excessive corrosion.
  • Use distilled or de-ionized water. Tap water may be usable in some regions.
  • When new, a deep-cycle battery may have a capacity of 70 percent or less. Formatting as part of field use will gradually increase performance. Apply a gentle load for the first five cycles to allow a new battery to format.
  • New batteries with low capacity many not perform as well as those that begin life with a high capacity. Low performers are known to have a short life. A capacity check as part of acceptance is advisable.
  • A start-stop battery typically has 25 percent more lead than a standard starter battery to attain a high cycle count. This is reflected in the corresponding price premium.

Know about hidden battery losses when estimating the energy reserve

If the battery was a perfect power source and behaved linearly, charge and discharge times could be calculated according to in-and-out flowing currents, also known as coulombic efficiency. What is put in should be available as output in the same amount; a 1-hour charge at 5A should deliver a 1-hour discharge at 5A, or a 5-hour discharge at 1A. This is not possible because of intrinsic losses and the coulombic efficiency is always less than 100 percent. The losses escalate with increasing load, as high discharge currents make the battery less efficient.

Peukert Law

The Peukert Law expresses the efficiency factor of a battery on discharge. W. Peukert, a German scientist (1855–1932), was aware that the available capacity of a battery decreases with increasing discharge rate and he devised a formula to calculate the losses in numbers. The law is applied mostly to lead acid and help estimate the runtime under different discharge loads.

The Peukert Law takes into account the internal resistance and recovery rate of a battery. A value close to one (1) indicates a well-performing battery with good efficiency and minimal loss; a higher number reflects a less efficient battery. Peukert’s law is exponential; the readings for lead acid are between 1.3 and 1.5 and increase with age. Temperature also affects the readings. Figure 1 illustrates the available capacity as a function of amperes drawn with different Peukert ratings.

As example, a 120Ah lead acid battery being discharged at 15A should last 8 hours (120Ah divided by 15A). Inefficiency caused by the Peukert effect reduces the discharge time. To calculate the actual discharge duration, divide the time with the Peukert exponent that in our example is 1.3. Dividing the discharge time by 1.3 reduces the duration from 8h to 6.15h.

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Figure 1: Available capacity of a lead acid battery at Peukert numbers of 1.08–1.50

Figure 1: Available capacity of a lead acid battery at Peukert numbers of 1.08–1.50

  • AGM: 1.05–1.15
  • Gel: 1.10–1.25
  • Flooded: 1.20–1.60

The lead acid battery prefers intermittent loads to a continuous heavy discharge. The rest periods allow the battery to recompose the chemical reaction and prevent exhaustion. This is why lead acid performs well in a starter application with brief 300A cranking loads and plenty of time to recharge in between. All batteries require recovery, and most other systems have a faster electrochemical reaction than lead acid.

Ragone Plot

Lithium- and nickel-based batteries are commonly evaluated by the Ragone plot. Named after David V. Ragone, the Ragone plot looks at the battery’s capacity in watt-hours (Wh) and discharge power in watts (W). The big advantage of the Ragone plot over the Peukert Law is the ability to read the runtime in minutes and hours presented on the diagonal lines on the Ragone graph.

Figure 2 illustrates the Ragone plot of four lithium-ion systems using 18650 cells. The horizontal axis displays energy in watt-hours (Wh) and the vertical axis is power in watts (W). The diagonal lines across the field reveal the length of time the battery cells can deliver energy at given loading conditions. The scale is logarithmic to allow a wide selection of battery sizes. The battery chemistries featured in the chart include lithium-iron phosphate (LFP), lithium-manganese oxide (LMO), and nickel manganese cobalt (NMC).

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Figure 2: Ragone plot reflects Li-ion 18650 cells.

Four Li-ion systems are compared for discharge power and energy as a function of time. Not all curves are fully drawn out.

Legend: The A123 APR18650M1 is a lithium iron phosphate (LiFePO4) Power Cell rated at 1,100mAh, delivering a continuous discharge current of 30A. The Sony US18650VT and Sanyo UR18650W are manganese based Li-ion Power Cells of 1,500mAh each, delivering a continuous discharge of 20A. The Sanyo UR18650F is a 2,600mAh Energy Cell for a moderate 5Adischarge. This cell provides the highest discharge energy but has the lowest discharge power.
Source: Exponent

The Sanyo UR18650F [4] Energy Cell has the highest specific energy and can run a laptop or e-bike for many hours at a moderate load. The Sanyo UR18650W [3] Power Cell, in comparison, has a lower specific energy but can supply a current of 20A. The A123 [1] in LFP has the lowest specific energy but offers the highest power capability by delivering 30A of continuous current. Specific energy defines the battery capacity in weight (Wh/kg); energy density is given in volume (Wh/l).

The Ragone plot helps in the selection of the optimal Li-ion system to satisfy discharge power while retaining the required runtime. If an application calls for a very high discharge current, the 3.3 minute diagonal line on the chart points to the A123 (Battery 1); it can deliver up to 40 watts of power for 3.3 minutes. The Sanyo F (Battery 4) is slightly lower and delivers about 36 watts. By focusing on discharge time and following the 33 minute discharge line further down, Battery 1 (A123) only delivers 5.8 watts for 33 minutes before the energy is depleted. The higher capacity Battery 4 (Sanyo F) can provide roughly 17 watts for the same time; its limitation is lower power.

A design engineer should note that the Ragone snapshot taken by the battery manufacturers represents a new cell, a condition that is temporary. When calculating power and energy needs, engineers must take into account battery fade caused by cycling and aging. Battery-operated systems must still function with a battery that will eventually drop to 70 or 80 percent capacity. A further consideration is low temperature as a battery momentarily loses power when cold. The Ragone plot does not take these decreased performance conditions into account.

The design engineer should further develop a battery pack that is durable and does not get stressed during regular use. Stretching load and capacity boundaries to the limit shortens battery life. If repetitive high discharge currents are needed, the pack should be made larger and with the correct choice of cells. An analogy is a truck that is equipped with a large diesel engine instead of a souped-up engine intended for a sports car.

The Ragone plot can also calculate the power requirements of capacitors, flywheels, flow batteries and fuel cells. A conflict develops with the internal combustion engine or the fuel cell that draws fuel from a tank, as on-board re-fueling cheats the system. Similar plots are also used to find the optimal loading ratio of renewable power sources, such as solar cells and wind turbines

Learn how certain discharge loads will shorten battery life.

The purpose of a battery is to store energy and release it at a desired time. This section examines discharging under different C-RATE and evaluates the depth of discharge to which a battery can safely go. The document also observes different discharge signatures and explores battery life under diverse loading patterns.

The electrochemical battery has the advantage over other energy storage devices in that the energy stays high during most of the charge and then drops rapidly as the charge depletes. The super capacitor has a linear discharge, and compressed air and a flywheel storage device is the inverse of the battery by delivering the highest power at the beginning. Figures 1, 2 and 3 illustrate the simulated discharge characteristics of stored energy.

Information on Battery - Basics About Discharging

Most rechargeable batteries can be overloaded briefly, but this must be kept short. Battery longevity is directly related to the level and duration of the stress inflicted, which includes charge, discharge and temperature. Remote control (RC) hobbyists are a special breed of battery users who stretch tolerance of “frail” high-performance batteries to the maximum by discharging them at a C-rate of 30C, 30 times the rated capacity. As thrilling as an RC helicopter, race car and fast boat can be; the life expectancy of the packs will be short. RC buffs are well aware of the compromise and are willing to both pay the price and to encounter added safety risks.

To get maximum energy per weight, drone manufacturers gravitate to cells with a high capacity and choose the Energy Cell. This is in contrast to industries requiring heavy loads and long service life. These applications go for the more robust Power Cell at a reduced capacity.

Depth of Discharge

Lead acid discharges to 1.75V/cell; nickel-based system to 1.0V/cell; and most Li-ion to 3.0V/cell. At this level, roughly 95 percent of the energy is spent, and the voltage would drop rapidly if the discharge were to continue. To protect the battery from over-discharging, most devices prevent operation beyond the specified end-of-discharge voltage.

When removing the load after discharge, the voltage of a healthy battery gradually recovers and rises towards the nominal voltage. Differences in the affinity of metals in the electrodes produce this voltage potential even when the battery is empty. A parasitic load or high self-discharge prevents voltage recovery.

A high load current, as would be the case when drilling through concrete with a power tool, lowers the battery voltage and the end-of-discharge voltage threshold is often set lower to prevent premature cut off. The cut off voltage should also be lowered when discharging at very cold temperatures, as the battery voltage drops and the internal battery resistance rises. Table 4 shows typical end-of-discharge voltages of various battery chemistries.

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Table 4: Nominal and recommended end-of-discharge voltages under normal and heavy load.

The lower end-of-discharge voltage on a high load compensates for the greater losses.

Over-charging a lead acid battery can produce hydrogen sulphide, a colourless, poisonous and flammable gas that smells like rotten eggs. Hydrogen sulphide also occurs during the breakdown of organic matter in swamps and sewers and is present in volcanic gases and natural gas. The gas is heavier than air and accumulates at the bottom of poorly ventilated spaces. Strong at first, the sense of smell deadens with time, and the victims are unaware of the presence of the gas.

A. There are few signs, which tell you that your car battery is getting old and need a replacement. Some useful signs that reflect the low or failing car battery are:

B. No appropriate functioning of various electrical devices of the car. Problem in the ignition/starting

C. Vehicle headlights look dim at idle and then brighten when you rev the engine improper cooling in the car cabin.

Proper maintenance of your car battery can increase its life and performance. Just follow some simple useful tips

a. Clean the dust from your car battery on regular intervals, because it can cause corrosion

b. If you find any kind of corrosion in your car battery, use solution of baking soda to wipe it out

c. Clean the battery surface or case on regular intervals

d. Periodically inspect the battery for several types of damages like fluid leaks, shell cracks, etc

e. Keep you car battery always fully charged

f. Keep battery connectors like the wire clean

g. Keep terminals and cables tight to prevent entry of toxins in the battery and also ensure proper flow of electricity

g. Keep terminals and cables tight to prevent entry of toxins in the battery and also ensure proper flow of electricity

h. To lubricate cables of the battery use Vaseline and petroleum jelly on regular intervals

i. Switch off music system, air-conditioner and lights, when it is in idle conditio

j. Check the fluid level of the car battery on regular intervals to ensure full fluid level

However, we recommend that you take proper caution while following any of the above tips as battery is an acidic and electrical device which may cause injuries if not handled properly.

Yes, all the batteries you receive are already charged.

We are focused to install your battery within 24 hours. We generally provide same-day delivery to our customers who order before 4:00PM each day. After you order the battery online, our customer executive will call you to confirm the order details and your availability. Though it is not possible to deliver at an exact time because of logistic reasons, you can specify the approximate time period for delivery.

Like all other products, manufacturer of the battery will takes care of the after sales service. If you have purchased any battery from STAR BATTERY HOUSE and it fails in its warranty period, then you are advised to contact the battery manufacturer like AMARON, EXIDE, SF SONIC or OTHER BRAND. You can contact them on THEIR CUSTOMER CARE:

Amaron AMCARE number: 1800-425-4848 (toll-free)
Exide Customer Care number: 1800-103-5454 (toll-free)
SF Sonic Customer Care number: 1800-180-11111 (toll-free)

Pro-rata warranty is a kind of partial warranty that is used for non-repairable products like tires and batteries. Under Pro-rata warranty, if a product fails before the end of the warranty cycle, the manufacturer replaces it at a cost that depends on the age of the item at the time of complaint. In this type of warranty only a part of the initial cost is covered. However, the replaced product is then covered by an equal new warranty.

If your battery fails in the pro-rata warranty cycle then depending on the value of the battery, you will get discount on the current price of the newly replaced battery. The pro-rata warranty is counted from the date of purchase to the date of complain.