How does a battery work?

How does a battery work?

A battery stores electricity for future use. It develops voltage from the chemical reaction produced when two unlike materials, such as the positive and negative plates, are immersed in the electrolyte, a solution of sulphuric acid and water. In a typical lead-acid battery, the voltage is approximately 2 volts per cell, for a total of 12 volts. Electricity flows from the battery as soon as there is a circuit between the positive and negative terminals. This happens when any load that needs electricity, such as the radio, is connected to the battery.

Most people don't realize that a lead-acid battery operates in a constant process of charge and discharge. When a battery is connected to a load that needs electricity, such as the starter in your car, current flows from the battery. The battery begins to be discharged.

In the reverse process, a battery becomes charged when current flows back into it, restoring the chemical difference between the plates. This happens when you're driving without any accessories and the alternator puts current back into the battery.

As a battery discharges, the lead plates become more chemically alike, the acid becomes weaker, and the voltage drops. Eventually the battery is so discharged that it can no longer deliver electricity at a useful voltage.

You can recharge a discharged battery by feeding electrical current back into it. A full charge restores the chemical difference between the plates and leaves the battery ready to deliver its full power.

This unique process of discharge and charge in the lead-acid battery means that energy can be discharged and restored over and over again. This is what's known as the cycling ability in a battery.

Why won’t my car start?

Why won’t my car start?

If the battery won't start your car, you usually refer to it as "dead," even though that's not technically correct. A battery that's merely discharged - from leaving your headlights on or from a damaged alternator - can be recharged to its full capacity. But a battery that's at the end of its service life can't be recharged enough to restore it to a useful power level. Then it truly is dead, and must be replaced.

 If the battery is discharged and not dead, you can jump-start it from another fully charged battery. About 30 minutes of driving should allow the alternator to fully charge the battery. But if the alternator or another part of the electrical system in your car is damaged, the battery will not recharge and a mechanic or service station also will not be able to recharge it. So if your battery keeps discharging, have your electrical system checked before you replace it. What looks like a bad battery could be an electrical system problem. If you have a bad component in the electrical system, it will keep draining a new battery, and you'll be stranded again and again.

Is there preventative maintenance I can do for my battery?

Is there preventative maintenance I can do for my battery?


The battery should be examined for cleanliness at regular intervals. Keep cell terminals and connectors free of dust and corrosion. Terminal corrosion may affect the performance of the battery and could present a safety hazard. Should corrosion be observed, disconnect the battery, unbolt and remove the connectors, and remove the corrosion by brushing the terminals and connectors with a dilute solution of baking soda and water (sodium bicarbonate). Reapply an anti-oxidizing grease before reconnecting and bolting the connectors. Always maintain proper records.


What should I consider when buying a battery?

What should I consider when buying a battery?

How do you know which battery is right for your vehicle? Here are some quick tips to help you make the right choice.

Check your vehicle manual for the original equipment manufacturer's recommendations for:

Battery group size - the battery size that will best fit the physical dimensions of your vehicle. Many vehicles can accommodate more than one group size.

Cold cranking amps (CCA) - CCA is critical for good cranking ability. It's the number of amps a battery can support for 30 seconds at a temperature of 0 degrees F until the battery voltage drops to unusable levels.

Reserve capacity (RC) - helps to power your vehicle's electrical system if the alternator fails. It identifies how many minutes the battery can supply ample power without falling below the minimum voltage needed to run your vehicle.

In general, for both CCA and RC, the higher the number the better. However, if you live in a cold climate, the CCA rating should be an important consideration in choosing a battery. Conversely, if you live in a high heat climate, you don't need as much CCA.

If you're looking for a deep cycle battery for marine or RV use, you must also consider:

  • The type of equipment to be powered
  • The number of amps needed to run the equipment
  • The number of hours you'll be using the equipment

Multiply the Amps by the Hours to determine the Amp Hours, or AH, required.
Equipment Current Draw (Amps) x Time (Hours) = AH

Example: Fishing Boat
Lights 10 x 5 = 50
Trolling Motor 1 x 5 = 5
Fish Locator 3 x 5 = 15
Radio 1 x 5 = 5
Total = 75 AH* 

*Look for a battery that will deliver the required amount of AH for the specified time and voltage.

For a safety cushion, increase the number of AH by 20%.

How do I jump start my vehicle?

How do I jump start my vehicle?



These instructions are designed to minimize the explosion hazard. Keep sparks, flames and cigarettes away from batteries at all times.

  • Both batteries should be of the same voltage (6, 12, etc.)
  • When jump starting, always wear proper eye protection and never lean over the battery.
  • Do not jump start a damaged battery; inspect both batteries before connecting booster cables.
  • Be sure vent caps are tight and level.
  • Be sure that the vehicles are not touching and that both ignition switches are in the “OFF” position.
  • Turn off all electrical equipment (radio, defroster, windshield wipers, lights, etc.)

The following steps should be followed exactly.

  1. Connect positive (+) booster cable to positive (+) terminal of discharged battery.
  2. Connect other end of positive (+) cable to positive (+) terminal of assisting battery.
  3. Connect negative (-) cable to negative (-) terminal of assisting battery.
  5. Be sure that cables are clear of fan blades, belts and other moving parts of both engines.
  6. Start vehicle and remove cables in REVERSE order of connections.

What causes battery failure?

What causes battery failure?

Battery Application and Installation

  • The battery being is not being used in the application for which it was designed
  • The battery is not the correct size for the application
  • The vehicle has excessive electrical accessories
  • The battery is not properly fitted into the vehicle
  • The battery cables are not clean
  • The battery cables have not been properly adjusted to fit the battery terminals

Service and Maintenance

  • The vehicle’s electrical system has been repaired or altered
  • The vehicle has been stationary for a long period of time
  • The vehicle has been brought in from or driven in another part of the country for a long period of time
  • The battery tray was washed free of corrosion or electrolyte

Visual Inspection

  • Terminals show signs of having been hammered, twisted or driven down into the cover
  • Side terminals show signs of over-torquing
  • Container or cover show signs of stress, damage or high temperature.
  • Ends of the battery are pushed out which indicates plate growth