How long should you charge a 12 volt battery

A car battery has 48 amps, so depending on how many amps your charger has, divide 48 by the charging rate and that is how many hours it takes. For example if your charger charges at 6 amps an hour, 48/6=8, so it will take 8 hours to fully charge a battery.

But before you throw a charger on it, let's see if your battery is worth saving.

First, if your battery is at least 3 years old it may be worth replacing as most batteries last about 4 years.

Also consider that if your battery is fully dead, it will be permanently damaged and can potentially strand you again.

Car Batteries in Cold Weather

This happens due to the summer heat can causing fluids in your battery to evaporate, reducing its effectiveness. However this usually isn't a problem until winter comes and fluids thicken, requiring more energy from your car battery to get it started.

My Battery is Still Good

It's important to note, that if your battery is completely dead, a slower charger is a healthier way to charge it. If you charge it too fast (anything more powerful than 16 volts) you can damage your battery.

The majority of automotive lead-acid batteries are now classed as being "maintenance free" but this doesn't mean there isn't anything you can do to help extend their service life.

If you're looking to extend the life of your battery there are a few easy things you can do at home. As a rule, the following items should be checked once a month to maintain optiumum performance, or at least every three months at a minimum.

1. Check the voltage

To check the voltage you'll need a voltmeter, which can be purchased cheaply from most major automotive parts stores. Check the voltage of your battery using the voltmeter to help determine your next course of action.
 

• 12.6V volts or above - Your battery is healthy and fully charged. No further action is required.
• 12.5 volts - Your battery is at a healthy state of charge, but we'd recommend re-checking it within a few days to ensure the voltage hasn't dropped any further.
• 12.1 - 12.4 volts - Your battery is partially discharged and should be recharged as soon as possible, using a suitable battery charger. The lifespan of your battery will be moderately affected if it remains within this voltage range for extended periods of time.
• 12.0 volts or below - At 12.0 volts your battery is considered to be fully discharged or 'flat' and should be recharged as soon as possible. The lifespan of your battery will be severely affected if it remains within this voltage range for extended periods of time. 
  • NOTE: After a full recharge, we'd strongly recommend visiting your local Century retailer to get a free battery check. This check will help determine whether a fault exists with the battery, or with your vehicle's charging system.

2. Check the electrolyte level

For maintenance free battery types, the State of Charge Indicator can be used to determine the battery's water level. If the State of Charge Indicator advises 'Replace Battery' it is important to visit an approved Century reseller for further testing and evaluation. If the electrolyte levels are too low and exposing the lead plates, the battery will need to be replaced to prevent the risk of an internal explosion.

3. Recharge your battery every 3 months

4. Keep the battery clean

Keeping your lead-acid battery clean is an easy way to extend service life. Ensure the top of the battery is clean, and that the terminals are free of corrosion. It is a little known fact that a dirty battery can discharge across the grime sitting between the terminal posts, reducing service life.

A thin coating of high temperature grease may also be applied to posts and cable connections for added protection.

NOTE: For show cars / vehicles which are rarely driven

For this reason, batteries which are fitted to show cars or vehicles which are rarely driven may require more frequent battery checks to ensure the voltage doesn't fall below 12.5 volts - the point at which battery wear begins to occur at an accelerated rate.

Check the state of charge or voltage of the battery regularly. Should the voltage drop below 12.5V, recharge the battery.

How do you know when your 12V battery is fully charged?

Can you overcharge a 12 volt battery?

How long should you charge a 12 volt battery at 2 amps?

Can you leave a 12V battery charging overnight?