Ppt of solar car

ELECTRIC- SOLAR VECHILE BATTERY

Solar car

BLOCK DIAGRAM OF CAR.WHAT IS BATTERY.AVAILABLE TYPES OF BATTERY-MARINE TYPE DEEP CYCLE BATTERYLEAD ACID BATTERY AGM BATTERY GEL BATTERY.BRIEF DESCRIPTION ABOUT LEAD ACID BATTERY.COMPOSITIONOPERATING PRINCIPLEINTERNAL RESISTANCETEMPERATURE EFFECT ON BATTERIES.CHARING AT NIGHT AND BAD WHETHER CONDITION.

TERMINOLOGY

A battery, in concept, can be any device that stores energy for later use. A rock, pushed to the top of a hill, can be considered a kind of battery, since the energy used to push it up the hill (chemical energy, from muscles or combustion engines) is converted and stored as potential kinetic energy at the top of the hill. Later, that energy is released as kinetic and thermal energy when the rock rolls down the hill. Not real practical for everyday use though.Common use of the word, "battery" in electrical terms, is limited to an electrochemical device that converts chemical energy into electricity, by a galvanic cell. A galvanic cell is a fairly simple device consisting of two electrodes of different metals or metal compounds (an anode and a cathode) and an electrolyte (usually acid, but some are alkaline) solution. A "Battery" is two or more of those cells in series, although many types of single cells are usually referred to as batteries - such as flashlight batteries.As noted above, a battery is an electrical storage device. Batteries do not make electricity, they store it, just as a water tank stores water for future use. As chemicals in the battery change, electrical energy is stored or released. In rechargeable batteries this process can be repeated many times. Batteries are not 100% efficient - some energy is lost as heat and chemical reactions when charging and discharging. If you use 1000 watts from a battery, it might take 1050 or 1250 watts or more to fully recharge it.What is a Battery?

Battery is another significant part of our design. In our design there is a battery connected with charger to solar panel and a supplementary battery to supply the extra power to motor. These devices are store the DC energy from PV panel in chemical form, and when needed converts the stored chemical energy to electrical energy. SOLAR SYSTEM BATTERY: In solar system batteries are charged and discharged randomly. Life time of battery is depends on charging and discharging of battery. The charging capacity of the battery measured with Amphour. Battery ratings are depended according to cycle. In vehicle there is used shallow cycle battery which means battery have cycles between 10% 15% of batteries total capacity. But in solar system there is used deep cycle batteries which have up to 50% 80% of total batterys capacity. This type of battery is best for solar project.

BATTERY There are many variety of batteries found in the market but only four types of batteries are usually used in solar system. Marine type deep cycle battery

Marine type deep cycle battery is basically used in boats and camps where small load is used to get powered. These types of batteries do not have capacity for continuous service with charger or discharger.

AVAILABLE TYPES OF BATTERIES:Lead acid battery Lead acid batteries can be used in solar energy storage. These types of batteries are deep cycled and have long life time for charging and discharging. Typical life time of lead- acid batteries is 3- 5 years. Life time of Battery actually depends on the charging and discharging cycle. Lead acid batteries releases some gas while charging. Thats why these batteries are needed to be kept outside or cross ventilated place, where air circulation is good enough. AGM battery

The full meaning of AGM battery is absorbed glass material battery. It allows the electrolyte to be suspended in close proximity with the plates active material. The AGM batteries are expensive batteries and typically cost twice as much as a premium wet cell battery. However they store very well and do not tend to sulfate or degrade as easily as wet cell. There is little chance of a hydrogen gas explosion or corrosion when using these batteries. The larger AGM batteries are typically good deep cycle batteries and they deliver their best life performance if recharged before allowed to drop below the 50% discharge rate. When Deep Cycle AGM batteries are discharged to a rate of no less than 60% the cycle life will be 300. AGM batteries are used in airplanes and hospitals where large charging time is needed.

Gel battery

Gel Cell battery is similar to the AGM battery because the electrolyte is suspended, but different because technically the AGM battery is still considered to be a wet cell. The electrolyte in a Gel Cell has a silica additive that causes it to set up or stiffen. The recharge voltage on this type of cell is lower than the other styles of lead acid battery. This is probably the most sensitive cell in terms of adverse reactions to over-voltage charging. Gel Batteries are best used in VERY DEEP cycle application and may last a bit longer in hot weather applications. If the incorrect battery charger is used on a Gel Cell battery poor performance and premature failure is certain. DC BATTERY SELECTION: Among the four types of battery all are not suitable for solar system and some are much expensive. So, for selecting a type of battery for a solar driven vehicle like ours, we always have to concern about less expensive, comparatively light in weight and high energy supply and consumed battery. Considering the economic factor and availability in our country we will be using Lead acid batteries, which are being widely used as a solar system storage device. These batteries are comparatively cheap, efficient in power storing and have a life time of 3 5 years. Though these types of batteries release some hydrogen gas while charging and needs some maintenance but still for large solar energy storage system lead acid battery is very popular. In our project we use two 12v-120Ah lead acid batteriesAs your electrical power usually needs to be available when the sun is not shining, it usually necessary to store electricity.The normal storage is the Lead-Acid battery.

This is a good point for some warnings:1. Lead Acid Batteries can contain a large amount of electrical energy which they are capable of discharging very quickly if any form of conductor is placed across their terminals.2. Lead acid batteries contain Shulphuric Acid which is corrosive.3. Lead Acid batteries give off hydrogen when they are being charged, which when mixed with air is explosive, and can be ignited by a small spark.

For the above reasons, I would not do any work on the batteries (ie.changing connections) unless I was wearing goggles to protect the eyes. I would also ensure that the batteries have not been charged during the last 2-3 hours to reduce the risk of hydrogen being present.

A Lead Acid cell has a nominal voltage of around 2 volts (depending on it's state for charge). A battery will consist of several cells connected together in series to produce the required voltage, usually either 12, 24, or 48 volts.For a small system, a 12 volt car or truck battery (consisting of 6 cells as one unit) could be used though they are not designed for the job.

The photograph to the right shows a battery of 12 individual cells for a 24 volt system. These cells will have been designed for deep cycle use.

The standard measurement for battery life is the number of cycles it can be expected to go through before becoming unable to hold a significant charge any longer, usually less than 70% its original capacity

Part - or most - of the loss in charging and discharging batteries is due to internal resistance. This is converted to heat, which is why batteries get warm when being charged up. The lower the internal resistance, the better. There is a good explanation and demonstration ofInternal Resistance hereSlower charging and discharging rates are more efficient. A battery rated at 180 amp-hours over 6 hours might be rated at 220 AH at the 20-hour rate, and 260 AH at the 48-hour rate. Much of this loss of efficiency is due to higher internal resistance at higher amperage rates - internal resistance is not a constant - kind of like "the more you push, the more it pushes back".Typical efficiency in a lead-acid battery is 85-95%, in alkaline and NiCad battery it is about 65%. True deep cycle AGM's (such as Concorde) can approach 98% under optimum conditions, but those conditions are seldom found so you should figure as a general rule about a 10% to 20% total power loss when sizing batteries and battery banks.Internal Resistance

Practically all batteries used in PV and all but the smallest backup systems are Lead-Acid type batteries. Even after over a century of use, they still offer the best price to power ratio. A few systems use NiCad, but we do not recommend them except in cases where extremely cold temperatures (-50 F or less) are common. They are expensive to buy, and very expensive to dispose of due the the hazardous nature of Cadmium.We have had almost no direct experience with the NiFe (alkaline) batteries, but from what we have learned from others we do not recommend them - one major disadvantage is that there is a large voltage difference between the fully charged and discharged state. Another problem is that they are very inefficient - you lose from 30-40% in heat just in charging and discharging them. Many inverters and charge controls have a hard time with them. It appears that the only current source for new cells seems to be from Hungary. In the past they were often used by railroads as backup power, but nearly all have now changed over to newer types.An important fact is that ALL of the batteries commonly used in deep cycle applications are Lead-Acid. This includes the standard flooded (wet) batteries, gelled, and AGM. They all use the same chemistry, although the actual construction of the plates etc varies.NiCads, Nickel-Iron, and other types are found in a few systems, but are not common due to their expense, environmental hazards, and/or poor efficiency.Temperature Effects on Batteries

Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. This is why your car battery dies on a cold winter morning, even though it worked fine the previous afternoon. If your batteries spend part of the year shivering in the cold, the reduced capacity has to be taken into account when sizing the system batteries. The standard rating for batteries is at room temperature - 25 degrees C (about 77 F). At approximately -22 degrees F (-27 C), battery AH capacity drops to 50%. At freezing, capacity is reduced by 20%. Capacity is increased at higher temperatures - at 122 degrees F, battery capacity would be about 12% higher.Battery chargingvoltagealso changes with temperature. It will vary from about 2.74 volts per cell (16.4 volts) at -40 C to 2.3 volts per cell (13.8 volts) at 50 C. This is why you should have temperature compensation on your charger or charge control if your batteries are outside and/or subject to wide temperature variations. Some charge controls have temperature compensation built in (such as Morningstar) - this works fine if the controller is subject to the same temperatures as the batteries. However, if your batteries are outside, and the controller is inside, it does not work that well. Adding another complication is that large battery banks make up a largethermal mass.

Thermal massmeans that because they have so much mass, they will change internal temperature much slower than the surrounding air temperature. A large insulated battery bank may vary as little as 10 degrees over 24 hours internally, even though the air temperature varies from 20 to 70 degrees. For this reason, external (add-on) temperature sensors should be attached to one of the POSITIVE plate terminals, and bundled up a little with some type of insulation on the terminal. The sensor will then read very close to the actual internal battery temperature.Even though battery capacity at high temperatures is higher, batterylifeis shortened. Battery capacity is reduced by 50% at -22 degrees F - but battery LIFE increases by about 60%. Battery life is reduced at higher temperatures - for every 15 degrees F over 77, battery life is cut in half. This holds true for ANY type of Lead-Acid battery, whether sealed, gelled, AGM, industrial or whatever. This is actually not as bad as it seems, as the battery will tend to average out the good and bad times.Click on the small graph to see a full size chart of temperature vs capacity.One last note on temperatures - in some places that have extremely cold or hot conditions, batteries may be sold locally that are NOT standard electrolyte (acid) strengths. The electrolyte may be stronger (for cold) or weaker (for very hot) climates. In such cases, the specific gravity and the voltages may vary from what we showNearly all large rechargeable batteries in common use are Lead-Acid type. (There are some NiCads in use, but for most purposes the very high initial expense, and the high expense of disposal, does not justify them). A few Lithium-Ion types are starting to make their appearance, but are much more expensive than Lead-Acid and most charge controllers do not have the correct setpoints for proper charging.The acid is typically 30% Sulfuric acid and 70% water at full charge. NiFe (Nickel-Iron) batteries are also available - these have a very long life, but rather poor efficiency (60-70%) and the voltages are different, making it more difficult to match up with standard 12v/24/48v systems and inverters. The biggest problem with NiFe batteries is that you may have to put in 100 watts to get 70 watts of charge - they are much less efficient than Lead-Acid. What you save on batteries you will have to make up for by buying a larger solar panel system. NiCads are also inefficient - typically around 65% - and very expensive. However, NiCads can be frozen without damage, so are sometimes used in areas where the temperatures may fall below -50 degrees F. Most AGM batteries will also survive freezing with no problems, even though the output when frozen will be little or nothing.BRIEF DESCRIPTION ON LEAD ACID BATTERYComponent [wt.-%] Lead (alloy) components (grid, poles) 25 - 30 Electrode paste (fine particles of Lead oxide and Lead sulphate) 35 - 45 Sulphuric acid (10 - 20 % H2SO4) 10 - 15 Polypropylene 5 - 8 Other plastics (PVC, PE, etc.) 4 - 7 Ebonite 1 - 3 Others materials (glass, etc.) < 0.5

COMPOSITION A rechargable battery is principally made up of one positive and one negative electrode placed in electrolyte. In a rechargable lead-acid battery the electrolyte consists of sulphuric acid (H2SO4) diluted in water, the postive electrode is made of lead dioxide (PbO2) and the negative of lead (Pb).During discharging the electrochemical energy stored in the batteries is consumed as electric power. In the chemical process sulphuric acid is absorbed from the electrolyte and lead sulphate (PbSO4) is formed at both electrodes .The reverse reaction takes place during charging, when electric power is transformed and stored electrochemically in the battery. Lead is formed at the positive electrode and lead dioxide at the negative, while sulphuric acid is released to the electrolyte .The chemical reactions taking place in a lead-acid battery.

PbO2 + Pb + 2H2SO4 discharge -> 2PbSO4 + 2H2O