Archive for Category Solar Power

1. Solar Batteries

Basically there are two types of batteries, starting (cranking), and deep cycle (marine/golf cart/Fork-lift trucks). The starting battery (SLI starting lights ignition) is designed to deliver quick bursts of energy (such as starting engines) and have a greater plate count. The plates will also be thinner. The deep cycle battery has less instant energy but greater long-term energy delivery. Deep cycle batteries have thicker plates and can survive a number of discharge cycles. Deep cycle batteries are designed to be discharged down as much as 80% time after time. The major difference between a true deep cycle battery and others is that the plates are SOLID Lead plates - not sponge. This gives less surface area, thus less instant power like starting batteries need. Although these can be cycled down to 20% charge.


A lead-acid battery is composed of plates immersed in sulfuric acid. Each plate has a grid upon which is attached the active material (lead dioxide on the negative plates, pure lead on the positive plates.) Negative plates are all connected together, as are all of the positive ones. When the battery is discharged, acid from the electrolyte combines with the active plate material. This releases energy and converts the plate material to lead sulfate. The chemical reaction between constituent parts of the electrolyte and the spongy lead of the negative plates and The lead dioxide at the positive plates turns the surface of both plates into lead sulphate. As this process occurs the hydrogen within the acid reacts with the oxygen within the lead dioxide to form water. The net result of all this reaction is that the positive plate gives up electrons and the negative plate gains them in equal numbers, thereby creating a potential difference between the two plates. The duration of the reactions producing the cell voltage is limited if there is no connection between the two plates and the voltage will remain constant.

What are volts?

It is the units of Potential difference across which a current flows.. The voltage of a battery depends on the number of cells. Each lead acid cell has 2 volts.

Recycling of Lead Acid Batteries

Lead acid batteries are 100% recyclable. The plastic containers and covers of old batteries are neutralized, reground and used in the manufacture of new battery cases. The electrolyte can be processed for recycled wastewater uses. In some cases, the electrolyte is cleaned and reprocessed and sold as battery grade electrolyte. In other instances, the sulfate content is removed as Ammonia Sulfate and used in fertilizers. The separators are often used as a fuel source for the recycling process.

Battery Capacity

The capacity of a battery to store charge is often expressed in ampere hours (1 Ah = 3600 coulombs). If a battery can provide one ampere (1 A) of current (flow) for one hour, it has a real-world capacity of 1 Ah. If it can provide 1 A for 100 hours, its capacity is 100 Ah. Battery manufacturers use a standard method to determine how to rate their batteries. The battery is discharged at a constant rate of current over a fixed period of time, such as 10 hours or 20 hours, down to a set terminal voltage per cell. So a 100 ampere-hour battery is rated to provide 5 A for 20 hours at room temperature. The efficiency of a battery is different at different discharge rates.

Battery Lifetime

Rechargeable batteries can be re-charged after they have been drained. This is done by applying externally supplied electrical current, which causes the chemical changes that occur in use to be reversed. Devices to supply the appropriate current are called chargers or rechargers.

Temperature Effects on Battery

Battery capacity (how many amp-hours it can hold) is reduced as temperature goes down, and increased as temperature goes up. The standard rating for batteries is at room temperature 25 degrees C. Battery charging voltage also changes with temperature.

Plate Thickness

Plate thickness (of the Positive plate) matters because of a factor called positive grid corrosion. The positive (+) plate is what gets eaten away gradually over time, so eventually there is nothing left - it all falls to the bottom as sediment. Thicker plates are directly related to longer life. Most industrial deep-cycle batteries use Lead-Antimony plates rather than the Lead-Calcium used in AGM or gelled deep-cycle batteries. The Antimony increases plate life and strength, but increases gassing and water loss.

Battery Cycles

A battery cycle is one complete discharge and recharge cycle. It is usually considered to be discharging from 100% to 20%, and then back to 100%. Battery life is directly related to how deep the battery is cycled each time. If a battery is discharged to 50% every day, it will last about twice as long as if it is cycled to 80% DOD. If cycled only 10% DOD, it will last about 5 times as long as one cycled to 50%.

Charging Lead Acid Batteries

A multi-stage charger first applies a constant current charge, raising the cell voltage to a preset voltage, takes about 5 hours and the battery is charged to 70%. During the topping charge, the charge current is gradually reduced as the cell is being saturated. The topping charge takes another 5 hours and is essential for the well being of the battery. If omitted, the battery would eventually lose the ability to accept a full charge. Full charge is attained after the voltage has reached the threshold and the current has dropped to 3% of the rated current or has leveled off. The final is the float charge, which compensates for the self-discharge.

Necessity of Equalization Charge

In any cyclic application, a series of batteries will always need to be equalized from time to time in order to ensure that the battery cells remain at the same voltage throughout the pack. During the charge cycle the voltages of the different batteries will very. In order to bring them all to the same level it is necessary to give some a slight overcharge in order to bring the other up to full charge. Equalization is done by allowing the voltage to rise while allowing a small constant current to the batteries. The voltage is allowed to rise above the normal finish voltage in order to allow the weaker batteries/cells to draw more current.

Calculating Battery Runtime

A battery can either be discharged at a low current over a long time or at a high current for only a short duration. At 1C, a 10Ah battery discharges at the nominal rating of 10A in less than one hour. At 0.1C, the same battery discharges at 1A for roughly 10 hours. While the discharge voltage of lead acid decreases in a rounded profile towards the end-of-discharge cut-off. The relationship between the discharge time (in amperes drawn) is reasonably linear on low loads. As the load increases, the discharge time suffers because some battery energy is lost due to internal losses. This results in the battery heating up.

Reasons for Failure of Batteries

Self discharge of plates and premature capacity loss; excessive float charge current and improper polarization of plates; shorts through separator, mossing or dendrite growth; overcharging of battery from high current and subsequent excessive gassing; excessive heat and loss of water; antimony transfer; low cold cranking performance; poor charge acceptance; inadequate high rate discharge performance.

Battery Do

  • Think Safety First
  • Do read entire tutorial
  • Do regular inspection and maintenance especially in hot weather
  • Do recharge batteries immediately after discharge
  • Do buy the highest RC reserve capacity or AH amp hour battery that will fit your configuration

Battery Donot

  • Donot add new electrolyte (acid)
  • Donot use unregulated high output battery chargers to charge batteries
  • Donot disconnect battery cables while the engine is running (your battery acts as a filter)
  • Donot put off recharging batteries
  • Donot add tap water as it may contain minerals that will contaminate the electrolyte
  • Donot discharge a battery any deeper than you possibly have to
  • Donot let a battery get hot to the touch and boil violently when charging
  • Donot mix size and types of batteries

2. Home Solar Power Systems - Advantages

Without doubt pollution control is one of the greatest advantages of using Home Solar Power Systems. One does not have to be an ecologist to realize the severity of the environmental problems that affect our planet. The inter-related issues of fossil fuels, pollution and climate change- all affect us one way or the other. The advantages of Home Solar Power Systems are not limited to environmental effects, although they are very relevant. There are many other benefits of using solar PV energy in terms of costs, maintenance or energy independence. Whether you are interested in this energy source because of a profound environmental concern, or you are more attracted to the idea of low-cost energy and money saving, going solar can prove to be a remarkably smart idea.


Over-exploitation of the Earth's non-renewable resources ( fossil fuels ) will eventually lead to their paucity, and consequently, higher costs, not to mention the issue of extreme pollution. Turning to a renewable source of energy thus becomes imperative.

Solar energy is renewable

Solar Energy is a renewable source of energy - we can count on for the sun to keep shining for billions of years. Using Solar Energy will not diminish it.

Solar energy is clean

Unlike fossil fuels, energy derived from the sun is not polluting. There are no gas emissions- it is totally clean. It contributes to reduction of the greenhouse effect. Solar energy is one of the best way to protect the environment and reduce the negative effects of fossil fuels on the environment.

Low costs

Solar energy is almost free. Once you install a Home solar power system, you can enjoy free energy as long as the Sun is up in the sky. Yes, the cost of installing such technologies can prove to be a substantial investment, but in time, you will save a lot of money on energy. If you think long-term, the benefits are considerable. Abandoning fossil fuel energy in favor of a low-cost type of energy is common sense. Relying on solar energy, which is free, will lower electricity bills to an affordable level. In case you choose to produce all the energy your house needs using the power of the sun, you will save serious money on bills.

Low maintenance costs

The maintenance of a solar system is easy and cheap. After the initial investment in installing the solar system, the chances of spending money on it will be quite limited.