2. collection of one or more electrochemical
cells in which stored chemical energy is
converted into electrical energy
3. Primary
Carbon-Zinc dry cell
Lithium
Mercury Oxide
Silver Oxide
Secondary
Lead Acid
(Flooded/Sealed)
Nickel Cadmium
Lithium Secondary
Chemical
Batteries
Other
Physical
Energy
Fuel Cell
Solar cell
Thermal
Nuclear Energy
4. Deep-cycle
Designed for maximum energy storage capacity and high cycle
count (long life), and are rated in Amp/Hours. This is achieved by
installing thick lead plates with limited surface area.
Typical applications are boats, Uninterruptible Power Supplies (UPS)
Engine Starting
Starter batteries are made for maximum power output, usually
rated in CCA (Cold-Cranking amps). The battery manufacturer
obtains this by adding multiple “lead plates” to obtain larger
surface area for maximum conductivity.
Typical applications are vehicles & motorcycles
5. Lead-acid batteries
basic components
are
commonly
made
of
A resilient plastic container
Positive and negative internal plates made of lead
Plate separators made of porous synthetic material
Electrolyte - 35% sulfuric acid and 65% water
Battery Terminals
five
6. Lead-Acid Batteries come in several different configurations
Flooded Lead-acid – Available in Deep cycle or Engine
starting as sealed or open variety
Sealed Lead-acid - The liquid electrolyte is gelled into
moistened lead plate-separators, which allow the case to
be
sealed.
Safety
valves
allow
venting
during
charge, discharge
and atmospheric pressure changes.
Absorbed Glass Mat Batteries (AGM) - sealed lead-acid
that
uses absorbed glass mats between the plates. It is
sealed,
maintenance-free and the plates are rigidly
mounted to
withstand extensive shock and vibration
7. The definition of Capacity is usually given in
Amp-hours (Ah) or Cold cranking amps
(CCA), cranking amps (CA), and Reserve
Capacity (RC)
(Ah) is specifies the amount of current
(measured in Amperes) it can provide over a
20 Hours period
(CCA) is a measurement of the number of amps
a battery can deliver at 0 F for 30 seconds
and not drop below 7.2 volts
(CA) is measured at 32 degrees F. This rating is
also called marine cranking amps (MCA)
(RC) is a very important rating. This is the
number of minutes a fully charged battery at
80 F will discharge 25 amps until the battery
drops below 10.5 volts
8.
9.
10. Parameters for Recharging
Charging Current - All batteries have a “maximum
current” at which they can be safely charged
Charging Voltage - Applying a voltage across its
positive & negative terminals that is higher than the voltage
it already has across them
Charging Time - The charge time of a sealed leadacid battery is 12-16 hours (up to 36 hours for larger
capacity batteries)
16. Conversion Efficiency
This denotes how well it converts an electrical charge into chemical
energy and back again. The higher this factor, the less energy is converted
into heat and the faster a battery can be charged without overheating. The
lower the internal resistance of a battery, the better its conversion efficiency.
Sulfation
Sulfation of lead-acid batteries starts when the electrolyte’s specific
gravity falls below 1.225. It results in a salt-like substance forming on the
battery plate surface and it can harden on the battery plates if left long
enough, reducing and eventually blocking chemical reaction between the
lead plate and the electrolyte. Equalization is the solution for this
problem.
17. Gassing
Batteries start to gas when you attempt to charge them faster than
they can absorb the energy. The excess energy is turned into
heat, which then causes the electrolyte to boil and evaporate. is the
suitable method for reduce this is good ventilated area.
Self-Discharge
The self-discharge rate is a measure of how much batteries
discharge on their own. The self-discharge rate is governed by the
construction of the battery and the properties of the components
used inside the cell (alloy of the lead, sulfuric concentrations of the
electrolyte, etc.).
18. The optimum operating temperature for the lead-acid battery is 25 C
(77 F).
As a guideline, every 8 C (15 F) rise in temperature will cut the
battery life in half.
A VRLA, which would last for 10 years at 25 C (77 F), will only be
good for 5 years if operated at 33 C (95 F).
Theoretically the same battery would last a little more than one year
at a desert temperature of 42 C (107 F)
19.
20. positive reacts
Ni(OH)2 - e + OH- -> NiOOH + H2O
Negative reaction
Cd(OH)2 + 2e -> Cd + 2OHwhole reaction
2Ni(OH)2 + Cd(OH)2-> 2NiOOH+ Cd+ 2H2O
When discharged
NiOOH + H2O + e Cd + 2OH- + 2e ->
Ni(OH)2 + OH- Cd(OH)2
Main applications are two-way radios, biomedical equipment and power tools
21. Positive reaction
LiCoO2 -> Li1-xCoO2 + xLi+ + xeNegative reaction
C + xLi+ + xe- -> Clix
whole reaction
LiCoO2 + C -> Li1-xCoO2 + CLix
Applications include notebook computers portable power tools, medical devices
and cell phones.
22. Ensure proper maintenance of engine starting batteries due to the
extreme importance of getting a ship under way in any
circumstances
Attention should be paid to the electrolyte level and specific
gravity for vented batteries
A boost charge shall be given if the specific gravity of the
battery cells meet the conditions stipulated by manufacturer
Ensure that the battery is not being overcharged
Keep engine starting batteries clean, dry and free of seawater
Period of inactivity for the ship of a week or more, give the
battery a normal charge
23.
Inspected for height of electrolyte once each week
The electrolyte level shall never be allowed to fall below the top
of the separators
Add pure distilled water at any time to replace that which has
evaporated
Add water just before the battery is placed on charge, as the
water remains on top of the electrolyte until mixed with it by
charging
After adding water, replace and tighten the vent plugs
Remove all water or electrolyte spilled during watering and
make sure that the tops and sides of the cells are clean and dry
24.
Ensure that distilled water that is to be used for watering
batteries and mixing electrolyte does not contain impurities
Use only premixed electrolyte when replacing spilled electrolyte
Fully charged specific gravity between the limits of 1.220 and
1.210 specific gravity at 27 C (80 F)
The specific gravity of a cell that has fallen below 1.210 shall
not be increased by the addition of acid untill it has been definitely
ascertained by test that the low-gravity condition is not due to
sulfation
The addition of acid to increase the specific gravity of a
sulfated cell will aggravate the existing condition
25.
The specific gravity of cells which exceed 1.220 shall be
cut by the removal of an appropriate amount of electrolyte
and the addition of distilled water
Sulfuric acid of a specific gravity greater than 1.350 shall
not be added to a battery
26.
Personnel handling or mixing electrolyte shall wear proper
protective items
If concentrated acid or electrolyte come in contact with the
skin, immediately wash the affected with freshwater
As soon as possible get the medical assistance
During electrolyte mixing the acid must be poured into the water
and not the water poured into the acid
The acid must be added slowly and cautiously to the water to
prevent excessive heating and splashing
The solution should be continually stirred by a glass rod while
the acid is being poured into the water to prevent the heavier acid
from flowing to the bottom of the vessel
27.
To prepare electrolyte, lead or rubber vessels and stirring rods
are necessary
Only pure distilled water shall be used
Every effort must be made to keep impurities from the
electrolyte while mixing, since they shorten battery life
Extreme care must be taken to ensure that acid container
(carboys) are absolutely airtight
The addition of even a small quantity of water to a carboy of
strong sulfuric acid may cause an explosion due to the sudden
evolution of heat
Notes de l'éditeur
Charging Current: All batteries have a “maximum current” at which they can be safely charged. High charging current means less time is necessary to complete the recharging process, however, a maximum value can also shorten battery life. Cases of extreme over-current could result in a hazardous condition due to battery overheating and thermal runaway.• Charging Voltage: A lead-acid battery is charged by applying a voltage across its positive & negative terminals that is higher than the voltage it already has across them. The greater the difference between the applied voltage and the battery voltage, the greater the charging current that will flow and the quicker the battery will be charged.• Charging Time: The charge time of a sealed lead-acid battery is 12-16 hours (up to 36 hours for larger capacity batteries). With higher charge currents and multi-stage charge methods, the charge time can be reduced to 10 hours or less. It takes 3 to 5 times as long to recharge a lead-acid battery to the same level as it does to discharge it.
Load testing is yet another way of testing a battery. Load test removes amps from a battery much like starting an engine would. A load tester can be purchased at most auto parts stores. Some battery companies label their battery with the amp load for testing. This number is usually 1/2 of the CCA rating. For instance, a 500CCA battery would load test at 250 amps for 15 seconds. A load test can only be performed if the battery is near or at full charge.
SulfationSulfation of lead-acid batteries starts when the electrolyte’s specific gravity falls below 1.225, or when voltage measures less than 12.4V. Sulfation results in a salt-like substance forming on the battery plate surface and it can harden on the battery plates if left long enough, reducing and eventually blocking chemical reaction between the lead plate and the electrolyte. It disables the ability of the battery to generate its rated voltage and amperage. Sulfation is the main reason a significant percentage of lead-acid batteries don’t reach their intended life span.
GassingBatteries start to gas when you attempt to charge them faster than they can absorb the energy. The excess energy is turned into heat, which then causes the electrolyte to boil and evaporate. The evaporated electrolyte can be replenished in batteries with removable caps such as most flooded deep-cycle batteries, however, many car batteries are sealed and thus need to be replaced when their electrolyte evaporates over time.
Ni(OH)2 consistence reduced with NiOOH consistence increasing during chargingthe positive electrical potential gradually raised, while with Cd increasingCd(OH)2 is decreased, and the negative electrical potential gradually reducedNiCd Batteries are UniqueNiCad batteries are different from typical alkaline batteries or lead-acid batteries in several key ways. One of the main key differences is in cell voltage. A typical alkaline or lead-acid battery has a cell voltage of approximately 1.5 V, which then steadily drops off as it is depleted. NiCad batteries are unique in that they will maintain a steady voltage of 1.2v per cell up until it is almost completely depleted. This causes the NiCad batteries to have the ability to deliver full power output up until the end of its discharge cycle. So, while they have a lower voltage per cell, they have a more powerful delivery throughout the entirety of the application. Some manufacturers make up the voltage difference by adding an extra cell to the battery pack. This allows for the voltage to be the same as the traditional type batteries, while still retaining the constant voltage that is so unique of NiCads. Another reason the NiCad batteries can deliver such high power output, is they have very low internal resistance. Because their internal resistance is so low, they are capable of discharging a lot of power very quickly, as well as accepting a lot of power very quickly. Having such a low internal resistance keeps the internal temperature low as well, allowing for quick charge and discharge times. This feature, combined with the constant voltage of the cells, allows them to put out a high amount of amperage, at a consistently higher voltage than comparable alkaline batteries.
Personnel handling or mixing electrolyte shall wear proper protective items rubber aprons, rubber boots and rubber gloves, so that the acid does not come into contact with clothing or skin and The face must be guarded by a full face shieldIf concentrated acid or electrolyte come in contact with the skin, immediately wash the affected area freely with a large quantity of freshwater for about 15 minutes