A battery is a source of electrical energy. Its smallest unit is called a (galvanic) cell. A battery usually consists of several individual cells electrically connected in series. The chemical energy as stored in each cell is converted directly into electrical energy when its terminals are connected to an electrical consumer.
The battery can thus be considered an electrochemical energy conversion system, not dissimilar to the internal combustion engine. The internal combustion engine converts chemical energy to mechanical energy. To do this two substances are required: Fuel and oxygen. A galvanic cell also needs two substances for energy conversion, represented by two electrochemically active electrodes of different composition, both of which are immersed in an electrolyte which provides a conductive medium between them.
One of the electrodes uses a metal such as zinc or lithium. Within the electrolyte it establishes a negative potential and consequently represents the negative electrode. The other electrode consists of an electron conducting compound which is rich in oxygen, e.g. manganese dioxide, silver oxide, nickel hydroxide or atmospheric oxygen in combination with a suitable oxygen electrode. This electrode establishes a positive potential within the electrolyte and consequently represents the positive electrode of the electrochemical system. Depending on the electrochemical system, the cell voltage will be between 1.2 V and 4 V. When connecting the system to an external load, electrical energy will be taken out of the system, while the chemical energy stored inside the cell or battery will be used up.
The smallest electrochemical unit of a battery is called a cell. The cell does not yet have a completed housing or ready-to-use contacts, and is usually connected with its neighboring cell within the battery via soldered or welded contacts.
In contrast to a cell, a battery is easily recognized by its completed housing fitted with ready-to-use contacts. Furthermore the housing is clearly labeled with the manufacturer's name, type designation, battery voltage, etc.
The electrical energy E delivered by a battery to an electrical device may be computed by formula E = U x I x t, where U is the battery's discharging voltage (in volts), I is the discharging current (in amperes) and t is the time of discharge (in hours). The unit of energy E as computed by the above formula is given in watt x hours.
A battery's power output refers to its ability to deliver a specific amount of energy within a fixed period of time. The power output P of a battery is calculated from the product of the discharging current I (measured in amperes) and the discharging voltage U (in volts), thus : P=I x U. The power output is expressed in watts.
The smaller a battery's inner resistance, the higher its possible power output. Its inner resistance must always be smaller than that of the electric device to be operated. Otherwise the battery voltage would break down, i.e. the battery would be unable to operate the device. At a given discharging voltage, a battery's power output increases with increasing electrode surface and operating temperature, and vice versa.
The terms "dry battery" and "liquid battery" are restricted to primary systems and date from the early development of galvanic elements. At that time, a liquid cell consisted of an electrolyte-filled glass container into which electrochemically active electrodes were immersed. It was only later that unspillable cells which could be used in any position and had a completely different construction were introduced, these being similar to today's primary batteries. These earlier cells were based on paste electrolytes. At that time they were known as dry batteries. In this sense today's primary batteries are also dry batteries.
The term "liquid battery" is in principle still applicable to certain modern secondary batteries. For large stationary lead-acid or solar batteries, liquid sulfuric acid is preferred for the electrolyte. For mobile applications unspillable, maintenance-free lead-acid batteries are recommended and have been available for many years. Their sulfuric acid is immobilized by a gel (or a special microglass mat).
Of all environmental factors, the temperature has the greatest effect on battery charge and discharge behavior. This has to do with the temperature- dependent electrochemical reactions occurring at the electrode/electrolyte interface, which may be considered the heart of the battery. If the temperature decreases, the rate of electrode reaction decreases too. Assuming the battery voltage remains constant, the discharging current drops and thus the power output of the battery. The opposite effect occurs if the temperature rises, i.e. the power output of the battery increases.
The temperature also affects the speed of transport processes within the electrolyte and its porous electrode. A rise in temperature accelerates transport processes, a decrease in temperature slows them down. The charge/discharge performance of the battery may also be affected.
The effect of the relative humidity depends on the battery system. It plays a key role in "open" battery systems (unlike closed battery systems).
An "external short circuit" can occur if the external terminals of a battery are bridged by any kind of conducting material. Depending on the battery system, a short circuit may have serious consequences. For example, the temperature of the electrolyte may rise, thus building up an internal gas pressure which may open the pressure valve of the battery and eject electrolyte from the battery. This can cause injuries. In extreme cases a detonation may even occur if the safety vent fails to respond (due to e.g. a molding defect during production).
You should therefore ensure that, for example, you do not carry charged or fresh batteries in the same pocket as coins or bunches of keys. Otherwise they may bridge the battery's terminals.
It is also important to avoid mechanical impacts which could deform the battery and result in internal electrode short circuits with the consequences described above.
An SLI battery is an automotive battery and stands for Start, Light and Ignition. Two substances dominate a standard SLI battery: lead and sulfuric acid. The positive electrode consists of lead-dioxide, the negative electrode is composed of finely distributed sponge lead. The sulfuric acid forms the electrolyte, ensuring the flow of ionic current between the battery's electrodes. The sulfuric acid's maximum conductivity is obtained at a gravimetric density of 1.28 kg/l. This is a typical acid density.
In an SLI battery, positive and negative electrodes are alternately welded to electrode stacks and set into the battery housing. A separator is placed between them to electrically isolate the positive and negative electrodes from each other. Six of these series-connected electrode stacks form a 12V battery.
The choice of the correct battery capacity is best made with the help of a checklist. Make a list of all the electrical consumers on your house trailer or boat. The power consumption of the individual installed units can be found in the relevant manufacturer's data sheet and should be given in watts. Dividing the power consumption by the voltage (12V or 24V) gives you the current in amperes. Now estimate the usage of the individual consumers in hours, total these and calculate the capacity required in ampere hours.
The calculation for the required battery capacity for a small sailing yacht using a 12V electrical system is given below :
Power in watts
Current in amperes
Service time in hours
Capacity in ampere hours
Position illumination, sonar and log
Cabin lighting, indoor lighting, autopilot system
Capacity requirement per day
In order to determine the battery capacity actually needed, the estimated result should be multiplied by a safety factor. A safety factor of 1.5 is recommended for "wet" batteries, i.e. batteries using liquid electrolyte. For gel batteries, as in our example, a safety factor of 1.7 should be used. In this way the risk of a deep discharge can be avoided provided the battery is properly maintained.
When applying the safety factor, the resulting capacity may lie in-between two existing Sepahan battery types. In this case the battery offering the higher capacity ought to be chosen.
Note: When comparing batteries, keep in mind that K5 or K20 means a capacity with a 5 or 20 hours discharge rate. It is impossible to guarantee that the new "5 hour capacity rating" as per the German Industrial Standard (DIN) will be adopted internationally by battery manufacturers. Presently, higher capacity values may be quoted on batteries or technical data sheets for batteries manufactured outside Germany.
An increasing number of electrical consumers used in modern automobiles depend on just one SLI battery. This is particularly problematic if the engine is not running, i.e. if the battery is not being charged. Such installations include heated seats, heated rear window, electric window openers, air conditioner, radio, mobile telephone, reading lights etc. The demand for inside comfort is rising constantly. As a result, the performance requirements for an efficient SLI battery are also increasing. However, a battery whose primary task is to ensure a reliable engine start cannot be expected to carry unlimited additional loads. Concepts are therefore being developed which, in the future, will provide vehicles with several batteries and cable networks.
Prior to installation or removal: switch off all electrical consumers.
Essential for installation: the battery must be installed in such a way that it is mechanically secured. Its degassing vents must not be covered. In the case of centrally vented batteries, the ventilation hose must be connected.
Essential for removal: when detaching the electrical connections, first remove the ground cable from the negative terminal. Then disconnect the cable from the positive terminal. This avoids short-circuits.
Two things are necessary - a second car and two jump leads for the positive and negative terminals. An electrical connection via jump leads from an SLI battery being charged by the running motor to the SLI battery of the car that won't start is normally the simplest solution. The start procedure is to be carried out in seven steps. You need to follow these steps:
Only use batteries with the same rated voltage.
Switch off both engines and all electrics (except the donor vehicle's hazard warning lights).
First connect the red jump lead to the positive terminal of the flat battery, and then attach the clip on the other end of the lead to the donor battery.
Then connect the black cable to the negative terminal on the donor vehicle before attaching the free end of the cable to a metal part away from the battery on the vehicle with the flat battery. The best area may be the engine block (see vehicle manufacturer's instructions).
It makes certain that the cables do not come into the range of the exhaust or the drive belt.
Start the engine of the donor vehicle, and then start the engine of the vehicle with a flat battery (max. 15 seconds) and let it run.
Remove the cables in the reverse order.
Note: please refer to the operating manual for your vehicle!
If an SLI battery is not properly maintained, battery failure may be the result. Unclean terminals may cause leakage currents, leading to energy loss. If a car is predominantly used in "stop and go" traffic while using installations like air conditioning systems, heated seats, heated front and rear window etc., the battery may be discharged excessively, thus causing difficulties, e.g. when trying to start the car in winter!
All automotive batteries require a certain amount of maintenance.
The surface of the battery should be kept clean and dry, otherwise leakage currents can build up, causing additional loss of charge. Batteries and terminals should be periodically checked to ensure a tight fit, and should be tightened if necessary. For automotive batteries with vent plugs, the following should be noted:
Battery fluid levels should be checked regularly. During the warmer months of the year, water consumption is normal. If consumption increases noticeably, the control voltage should be checked by a specialist. If the battery fluid level is too low, it should be topped up with purified water. Acid should never be used. When storing automotive batteries, the following should be noted:
Batteries should always be kept as fully charged as possible to prevent the formation of large lead sulfate crystals. Batteries should never be stored in discharged (or partially discharged) state!
Charged batteries in storage should be checked regularly, and should be charged when the acid density falls below 1.20 kg/l.
Vehicle electrical systems can be found on airplanes, ships, house trailers and cars. It encompasses all kinds of electrical installations, consumers, wiring and cables, as well as the battery, generator and starter.
SLI batteries are used repeatedly for applications they never were made for, e.g. as power supplies for house trailers, to provide extra electrical energy for mobile ambulances (lights etc.), as energy supplies for boats, or as backup batteries for computers.
An SLI battery's primary task is to provide a high power output for a short period of time necessary to start a combustion engine. In order to provide these high current outputs, large electrode surface areas are necessary. This is realized by using many thin electrodes connected in parallel.
Permanent cycling, i.e. charging and discharging, of 60-80% of the rated capacity at medium currents over a longer period of time can produce strong mechanical forces within the thin plates of the SLI battery. These forces may cause the active mass to separate from the electrode grid and thus lead to premature wearing of the battery.
Therefore, when discharging 60-80% of a battery's rated capacity, special batteries should be used which are designed for this type of application.
In order to guarantee optimal battery life, "gel" batteries may be discharged (cycled) up to 60%, whereas wet batteries may be discharged up to 80%. Thus - depending on technology - 60% or 80% of the rated capacity will be available.
Deep discharges should also be avoided with these batteries. Deep discharges which occur when capacity is withdrawn beyond the minimum voltage limit cause the battery's service life to be shortened. In order to protect the battery from deep discharge a "deep discharge protector" should be used.
Many factors affect the life of a battery CLIMATE: Colder climates tend to be hard on batteries from a starting standpoint, and for the fact that many people put their bikes away for the season when not using. Sometimes without charging properly. Hotter climates tend to discharge batteries quicker, and dry out batteries quicker. "Average" climates are the best for long battery life. USEAGE: A battery that is used every day has the most chance of living a long life. Batteries that sit a lot, many times are neglected. This shortens overall life. Periodic charging is the best defense. APPLICATION: How well is the battery charged in the vehicle? Some vehicles have better charging systems than others. Older bikes have worse charging systems than new ones. Are there a lot of extra accessories on your vehicle? Sometimes a battery has a hard time keeping up with additional electrical drains, thus wearing it out quicker. NEGATIVE FACTORS:
SULFATION - Sulfation is a build up of crystals on the plates of a battery. This comes from not charging a battery properly. The more sulfation that builds up, the harder the battery is to charge, until finally it does not charge at all.
WATER LOSS - Water loss can come from overcharging, or just simple evaporation over time. This only happens with conventional batteries. This does not happen with sealed AGM batteries. Once the plates of a battery are left open to the air, above the fluid level, they can corrode very quickly. Corrosion can cause an internal short, and very quickly destroy the battery. Keeping proper water levels maintained is very important.
LACK OF CHARGING - As mentioned previously, lack of proper charging is the main reason that a battery will not last as long as it should. At the very minimum, a battery should be charged once a month if left unused.
COMPLETE DRAIN - Have you ever left your key on, and totally killed the battery? If recovered in a short time period, the battery should charge back to 100%. But every time this happens, it is similar to the battery having a "heart attack", and shortening its overall life. Always turn your vehicle off with the keyed ignition switch, not the "kill switch".
TYPES OF BATTERIES, WHICH IS BETTER..... SEALED AGM BATTERIES - Last Longer. They are not "open to the air" by way of a vent tube. They do not lose water. They are also packed tighter. Plates do not vibrate causing material to shed from the plates and short out. Or worse yet, simply breaking apart in some high vibration applications. Sealed AGM batteries typically last 3 to 5 years on an average. 6-8 years is easily obtainable with proper maintenance. Typically sealed AGM batteries will give warning before completely dying. They will start slower, and require more charging. This is your clue to replace the battery. Typically they do not fail all of a sudden. Conventional "acid-filled" batteries have a harder life, for many of the reasons listed above. This older style battery typically only lasts 2 to 3 years on average. Although, 4-5 years is possible, in the best environments, and with excellent maintenance.
Good battery maintenance should include the following: 1. Always keep the acid level between Lower and upper lines on front side of the container (conventional type batteries). 2. Do not let the battery stand in a discharged condition. 3. Charge battery once a month. 4. When motorcycle is stored over 30 days, plug in a Yuasa automatic battery charger to maintain a proper storage charge. 5. Keep battery top clean, dry and free of dirt. 6. Clean battery terminals to prevent corrosion. Inspect vent tube, ensuring that it is not bent, twisted or clogged. 7. Protect the battery from strong impacts or shocks.
Sudden battery failure is simply that! One minute the battery functions properly, and the next it fails to provide electrical power to your vehicle. In the vast majority of situations where this occurs, an internal battery connection failure is to blame. These internal failures usually are the result of poor care and maintenance of the battery. To help ensure that this condition does not occur with your battery, follow the care and maintenance instructions included with the battery or refer to our maintenance section of this web site.
When a battery is in an excessively discharged state, it does not readily accept a high current charge. The battery may appear to be accepting charge, but charging is occurring only at the surface of the plates. In such a case, the battery must be charged at a low current flow for an extended period of time: for example, up to 24 hours on a Yuasa automatic charger or equivalent smart charger.
The following characteristics will tell you if a battery has been properly charged: 1. The specific gravity of the acid is over 1.275 (conventional type batteries only). 2. Maximum voltage output across battery terminals can be maintained at constant level for two hours. 3. Open circuit voltage is stablilized @12.7v or higher @ 6.3v or higher for 6 volt batteries.
When not in use, a battery discharges on a daily basis sometimes up to 0.5-1%. This rate of discharge increases when the climate is warm. To make up for this loss from disuse, a boosting charge should be given once a month.
Discoloration of plates with white lead sulfate crystalline deposits may occur when the battery has been left for a considerable time in a discharged condition. It can also occur as a result of the plates being exposed to air due to low electrolyte level, or when a new battery is filled with acid and stored without being charged. This phenomenon is called sulfation. Once plates have been sulfated, the activity of the affected area is permanently impaired, and the battery may not be restored to its original capacity.
The main reason is that batteries have to work so much harder in cold weather. Engine oil is thick, so engine cranking effort is much higher. Also, a battery's charging efficiency decreases in cold temperatures. In addition, gasoline does not vaporize as readily in the cold, which means that even more battery cranking effort is required.
"VRLA" stands for Valve Regulated Lead Acid, "MF" stands for Maintenance-Free, "AGM" stands for Absorbed Glass Mat, and "SLA" stands for Sealed Lead Acid. All 4 of these terms basically refer to the same type of battery.
"Standard SLI" (Starting, Lighting and Ignition) refers to any standard, non-sealed battery. In this case SLI refers to older style batteries used for powersports type vehicles.
When a battery is charged and discharged, water contained in the electrolyte is decomposed, generating hydrogen and oxygen gases. These gases are vented out of the battery through the exhaust vent tube to prevent potentially damaging high pressure gas accumulation. Every exhaust tube comes with a small slit at each end. The reason for this slit is to release the gas, in the event that the bottom of the tube gets clogged by road debris. For this reason, it is most important to make sure the slit at the top near the battery is functioning properly. As as side note, always be sure to remove the small red sealed tube when installing the battery. Never put this red tube back on to the battery after it is activated. Gases built up in a battery that is not allowed to vent can cause serious damage, and possible injury, if the battery bursts.
That is something a lot of "old timers" say. The reason they say that is in the "olden days" vehicle starting batteries used to be made with a hard rubber container. This hard rubber would eventually get mini cracks and become porous. So, when placing a battery on the ground or concrete, the battery would discharge through the ground or wet concrete. Nowadays, containers are made from a solid plastic that does not allow any current to flow through it, so the batteries do not discharge, even if they sit in a few inches of water. That is why you will not find your battery having trouble from sitting on the ground or concrete.
A lead-acid battery is composed of a series of plates immerse in a solution of sulfuric acid. Each plate consists of a grid upon which is attached the active material (lead dioxide on the negative plates, pure lead on the positive plates.) All of the negative plates are connected together, as are all of the positive plates. When the battery is discharged (when it is subjected to an electrical load), 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.
Different Types of 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.
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.
Strictly, an electrical "battery" is an interconnected array of one or more similar "cells". A car battery is a "battery" because it uses multiple cells. Multiple batteries or cells may also be referred to as a battery pack as a set of multi-cell 12 V batteries in an electric vehicle. A 12 Volt monoblock battery consists of 6 cells, but a plante’ or 2 Volt tubular battery is a battery though it consists of a single cell.
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.
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 Batteries 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.
Cycles vs. Life 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%.
Yes. All batteries, regardless of their chemistry, will self-discharge even when no load is present. At a temperature of 27 degrees C, a lead acid battery will self-discharge at a rate of approximately 4% a week. A battery with a 125 amp-hour rating would self-discharge at a rate of approximately five amps per week. A rule of thumb is to ALWAYS keep your batteries fully charged while not in use!
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.
n 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 the 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.
Sulphation (or Lead Sulfate) is the formation of hard crystals on the plates of your battery. Initially, the lead sulfate coating is soft, thin and easily reconverted into lead and sulfuric acid when battery is recharged. It is important to remember, the longer your battery remains discharged, the more it will begin to form hard crystals of lead sulfate…RECHARGE YOUR BATTERY AS SOON AS POSSIBLE!
How often use and recharge your batteries will determine the frequency of watering. It is best to check your battery water level frequently and add distilled water when needed. Never add tap water to your battery. Tap water contains minerals that will reduce battery capacity and increase their self-discharge rate. And never add acid. Only distilled or de-ionized water should be added to achieve the recommended electrolyte levels.
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 Maintenance Procedure
Maintenance is an important issue. The battery should be cleaned using a baking soda and water mix; a couple of table spoons to a pint of water. Cable connection needs to be clean and tightened. Many battery problems are caused by dirty and loose connections. A serviceable battery needs to have the fluid level checked. Use only mineral free water. Distilled water is best. Don't overfill battery cells especially in warmer weather. The natural fluid expansion in hot weather will push excess electrolytes from the battery. To prevent corrosion of cables on top post batteries use a small bead of silicon sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly (Vaseline), then place cable on the post and tighten. Coat the exposed cable end with the grease. Most folks don't know that just the gases from the battery condensing on metal parts cause most corrosion.
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.
Don't add new electrolyte (acid).
Don't use unregulated high output battery chargers to charge batteries.
Don't disconnect battery cables while the engine is running (your battery acts as a filter).
Don't put off recharging batteries.
Don't add tap water as it may contain minerals that will contaminate the electrolyte.
Don't discharge a battery any deeper than you possibly have to.
Don't let a battery get hot to the touch and boil violently when charging.