Originally submitted by T:
- 1 Batteries:
- 1.1 Safety:
- 1.2 A Battery's Rating:
- 1.3 Electroyte Level:
- 1.4 Sulphating:
- 1.5 Using the Battery:
- 1.6 Fitting the Battery to the Car:
- 1.7 Battery Voltage:
- 1.8 Flat Battery:
- 1.9 Battery Tips:
- 1.10 The Screw Cap Battery:
- 1.11 Connecting the Charger:
- 1.12 Using A Hydrometer:
- 1.13 Longest Battery Life:
- 1.14 Deep Cycle Batteries:
- 1.15 Battery Storage:
- 1.16 Links:
- 1.17 Terms:
As the lower image shows, Batteries can *explode* and shower the surrounding area with Sulphuric Acid. Don't allow any spark or flame to occur near a Battery. *Never* hold a match or cigarette lighter over it to see how much electrolyte is present in the cells. When connecting or disconnecting Battery leads to the terminals make sure everything in the car is turned *off* to prevent sparks.
2Batteries can spit Sulphuric Acid so use Eye Protection to avoid Eye Injury from getting Acid in your Face or Eyes.
A Battery's Rating:
A Battery's output is rated by both its output voltage (. i.e. 6v 12v) and its minimum/maximum output or Cranking Amps (CA) is the factory tested maximum cranking amps that the battery is capable of when new @ 0 Degrees Celsius 32 Degrees Fahrenheit. Normally at least 100+ more than the CCA.
Cold Cranking Amps (CCA) is the factory tested minimum cranking amps the battery is capable of when new @ -5 degrees Celsius 23 degrees Fahrenheit. This test by law must be on every battery. In Australia it is fine, but in some colder climates i.e. -15C They are told to start their cars with headlights on, to excite the battery. Maybe useful info when you're up the snow.
Plates (Pl) is the amount of plates the battery contains i.e. 8/9/10/11/12/13 in a car selection, rule of thumb, the more plates contained in the battery, the more cranking amps will be attained. For normal use a 10 or 11 plate battery is fine, but if you are running any accessories, CD player, Driving lights, etc, etc, you will need at least a 13 plate battery.
NOTE: Some manufacturers for some reason are no longer putting plate information on their batteries. But the old addage "You only get what you pay for" is relevent! Also the heavier the battery (more lead) is a good sign!
Inside the Battery there is a clear liquid that looks like Water. It's actually Sulphuric Acid. The Level of the Sulphuric Acid must be kept at the Manufacturer's recommended Level at all times. Add Distilled Water to the Battery to bring this Level back to the proper height. Don't use Tap Water. Avoid overfilling the Battery with Distilled Water. If the Battery is left with a low Electrolyte Level the Battery will Sulphite and fail.
This occurs when the Battery's Electrolyte Level is allowed to get too low, or if the Battery is allowed to stand at low Charge or if the Battery never gets charged properly or if the Battery is too small for the Car. A Shorted Cell means the Battery will not deliver it's full 12 Volts, more like 10 Volts because one Cell is not working properly.
Using the Battery:A car battery should start the car and then be immediately fully recharged by the alternator or the battery's life will diminish. Avoid leaving headlights or any other electrical load on without the engine running if you want the maximum life from your car's battery.
Fitting the Battery to the Car:
Make sure everything in the car is turned *off* to prevent any sparks occurring when you connect the terminals. When a battery is first fitted to a car, the Battery Posts and the Cable Terminals must be clean and free of corrosion. Eye protection is vital with this work since batteries contain corrosive acids and any corrosion often contains oxides that
can cause injury. A wire brush can be used to clean the posts, emery paper or a fine round file can get into the inside of the cables' terminals. Once the battery terminals are connected to the battery it is vital to cover them with grease. Auto electricians sell Battery Post grease. Gases that escape the battery during charging or discharging are attracted to the one or the other Battery Post. The grease prevents them generating corrosion on the post, terminal or both. Battery Post and Cable Terminal corrosion can create starting/charging problems. It's almost a science what will happen, butsimply stated a high resistance will appear between the battery post and its terminal. The high resistance will heatup and sometimes spark during cranking. It will also prevent the start current from getting to the starter preventing the engine from cranking. During charging the high resistance will minimise the alternator's current flow into the battery drastically preventing the battery from being charged properly. The battery must be secured to the vehicle using a suitable clamp to prevent the battery bursting open or having its teminals shorted in the event of a collision of heavy stop.
In a normally operating car, the rated output of the alternator (usually stamped on the alternator's casing) should be present on the battery anytime the engine is at or above 1,000 rpm. If not the battery will supply the car's devices and a reduction in the life of the battery will result.
If the charging system is not working the Battery will eventually become discharged or flat and the car will not crank. See Alternator. If the wires connecting the Battery to everything else won't carry the current, the Battery can become discharged or unable to supply current even if it is brand new. See Dim Lights.
If the Battery has a Shorted Cell it should be replaced. A Shorted Cell will result if a Battery has been left unused for a very long time or if the Alternator hasn't been charging it properly.
As stated earlier the battery contains very corrosive Sulphuric Acid, and must be treated with utmost caution. When removing/replacing battery keep well away from body, if any of the fluid touches your clothing. Wash with water and start saving your money to replace the garment!
Batteries do not go flat without reason. Fully recharge it and put back into the vehicle. Make sure that all electrical accessories are turned off. Connect the positive terminal. Then just touch the negative terminal on the negative battery post. If you see a spark (don't worry - 12 is nowhere enough volts to hurt you) this indicates you probably have a significant leak. ie. something is drawing current when it should not be, and purchasing a new battery will not fix the problem. Go and see your auto electrician. Even if you do not see a spark, there could still be a leak draining the battery.
Make certain that the charging system is working correctly - very close to 14 volts at the battery terminals with engine running above idle. The voltage present should match that stamped on the Alternator.
The Screw Cap Battery:
Screw cap Batteries are not value for money and will soon perish. These are best suited to cars with Generators. A high capacity no/low maintenance battery will out last one of these. The warranty is likely to be double that of a screw cap battery.
===Recharging From a Battery Charger:===Firstly top up the fluid levels in each cell if necessary, preferably with distilled water. The fluid (electrolyte) must cover the plates completely. A slow charge (2 to 5 amps) is better for the battery if you have the time. Remove the caps to view each cell and allow expansion during charging. *NO NAKED FLAMES OR CIGARETTES!
Connecting the Charger:
Don't connect the Charger's leads directly to the Battery Terminals. Connect the Positive to the Starter Tap and the Negative to the Engine Block. This will prevent sparks from occurring near the Battery.
The charge is complete when the cells are bubbling. Usually the voltage will be approximately 14.5 volts. Don't charge over 15 volts! In a good battery, all the cells will behave much the same (i.e. all start bubbling at about the same time).
While charging look at each individual cell. Eye protection is advised. If one cell is bubbling more or less than the others (normally the end ones) it is a fair indication that the cell has actually separated and the battery is on its way out!
Using A Hydrometer:
A Hydrometer will give you the specific gravity of your battery fluid, ie, the acid content.
Remove the screw caps, and place the rubber straw end into battery. Squeeze the rubber ball end and release to suck fluid into central chamber. You must have enough fluid in the chamber so that the glass indicator is not touching the bottom, and actually floating. Carefully remove Hydrometer from battery and look at the top fluid level. Your internal float should have Green, good. White, fair. Red, recharge, on the stem. Line up the fluid level with the indicator to get the reading.
NOTE: The battery must be fully charged to get a correct reading. Replace the hydrometer back into the same hole you took it from, and squeeze again to expel fluid. Repeat the same procedure in each hole and record the readings. If one reading is totally different from the others, you have a seperated cell and the battery is of no use.
Longest Battery Life:
Longest battery life is achieved by using the low/no maintenance (no screw caps)
type battery for a 6 cyl engine (typically a 550 Cold Cranking Amps) which will be able to deliver the heavy current required to crank the engine on a cold night.The high capacity battery will be able to accept the aggressive recharge
current that the alternator will ram back into it. Longest Battery life comes from having the Battery start the car then have the Alternator fully recharge it. As far as possible the Alternator should power everything in the car once the Engine is running.
Deep Cycle Batteries:
Deep Cycle batteries are the only batteries designed to be totally discharged, and then recharged without suffering internal damage or having their life reduced.Deep Cycle Batteries have deep troughs under each cell to ensure that any loose material will not build up high enough to short out the cell plates which is why Deep Cycle Batteries are physically larger than normal car batteries (Storage Batteries).
Deep Cycle batteries are designed to sit still, and generally the plates are not as robust as vehicle batteries. They usually fail sooner in vehicles from the vibration. Since they usually cost significantly more as well, why would you bother?
A Storage Battery that is totally discharged will sustain some damage (the Lead/Acid will sulphate, i.e. start eating itself internally).
The warmer a Battery is, the faster it will discharge so cool storage is an advantage. Also a Battery that stands idle for too long will sulphate and end up with shorted cells which means it will be ruined so it's advantageous to use the Battery periodically and leave it fully charged after any use.