Car batteries naturally charge via the alternator when a vehicle is in motion. So even when you park the car, there is still some charge left in the battery you can use on your next trip. If you start your car one day, and your engine fails to pick up, or your car suddenly stops in the middle of the road, you may have a dead battery.
Here, your only option is to revive the battery with a charger. Since batteries and chargers come in different sizes, we will discuss the 12V battery and a corresponding 6 amp battery charger. So how long to charge a 12v car battery at 6 amps?
How long to charge a 12V car battery at 6 amps?
A 12V car battery will take an estimated 4 to 10 hours to charge using 6 amp battery chargers. It is only an estimate; the exact time charge time will depend on several factors. First is the battery charge left; ideally, a car battery at 50% will charge faster than a battery with only 10% charge left.
Another factor that affects charging time is the battery size and type. A battery with a larger capacity will usually take more time to charge. Similarly, an AGM/GEL battery will take a shorter time to charge than the standard wet battery.
Following is the charger's charging rate. A charger that delivers more amperes will charge your battery faster than one with a slow amperage. Lastly is the condition of your battery. A new or adequately conditioned battery will charge faster than an old battery that has been repaired many times.
How to charge a 12V car battery at different amps
Usually, car battery chargers come in different amps. So how slow or fast your battery charges depend on your battery capacity and charger amp.
For example, if a 2 amp battery charger takes 48 hours to charge a 12V battery, a 4 amp battery charger will take 24 hours. Generally, the charge time reduces as the charger amp increases. Invariably, lower battery amps will give a slow charge, while higher battery amps will give a fast charge.
But ideally, fast is never the best way to go as it may cause irreparable damage to your battery. As a rule, ensure your battery charger amp is one tenth of your battery's capacity. That is, a 60 ah battery should be charged with a 6 amps battery charger.
Why does car battery fail?
If your car battery suddenly dies, it may be caused by some of the following.
Human error
Sometimes drivers get too tired after a long day and forget to turn off the headlights or properly close the doors or trunks. Because your headlights feed off your car battery, your battery may drain overnight. This is because the battery is giving out power without recharging.
Inadequate charging
The charging system consists of different parts to charge your battery when the car is moving. However, your battery will not get charged. if the charging system fails due to a loose alternator belt or even a faulty tensioner. Instead, it will be draining even while your car is in motion.
Parasitic drain
Parasitic drain is a situation where some vehicle components still run even after turning off the car engine. Usually, components like the clock or radio will feed off your battery. If an electrical problem pops, the parasitic drain will intensify.
Some things that can cause a parasitic drain include a bad door light switch, faulty door lock actuator, and trunk lock switch. Others include defective stereo or stereo wires, improperly installed aftermarket parts, etc.
Extreme temperature
Most batteries find it challenging to handle extreme conditions. Temperature above 100°F and below 10°F can affect your battery charge. Extreme temperature causes the build-up of lead sulfate leading to long-term depletion. Such build-up can also prevent your battery from holding a charge.
Faulty alternator
The alternator's responsibility is to charge the battery as the car moves. It also supplies current to electrical components. If it's faulty, it will not charge the battery.
Corroded or loose battery connections
Even with a functional alternator, your battery will not get charged properly if the battery has loose or corroded connections.
Short drives
The alternator gets to charge the battery only when your car is moving. If you don't take enough drive long enough, the alternator won't get power to charge the battery.
The battery is too old
If the battery is too old, it won't be able to hold a charge even with a proper charge from the alternator.
How to fix car battery issues
The best way to fix battery issues is to diagnose the cause of the problem. But usually, the following can help.
● Ensure you put off all lights-headlights, interior lights, etc,
● Check to see if the alternator is working correctly. Fix broken alternator.
● If possible, avoid using your batteries in extreme temperatures.
● Check and fix loose or corroded battery connections.
● Check and fix any components that could cause parasitic drain.
● Check your water level and fill if necessary. Vehicles that use conventional unsealed lead acid may experience low acid levels, which can decrease the battery's power and ultimately lead to battery failure.
● If none of the above restores battery charge, get a battery charger and charge the battery. If, however, it's too old, it won't be able to retain charge, so you may need a new battery.
FAQs
Should I charge my battery at 2 or 6 amps?
Whether or not to charge at 2 or 6 amps depends on your car battery amperage and how much you're willing to wait.
A 6 amp charger may take overnight to charge a 12V battery with 48 ah, which is ideal.
However, while a 2 amp charger can suffice here, it will take too long(up to 3 days). Many may not have the patience to wait this long and might stand the risk of overcharging the battery.
How do I know when my car battery is fully charged?
Some car battery chargers have a feature that should let you know your battery's charge condition. However, if this feature isn't available, you can go for a voltage check using a multimeter or voltmeter. A fully charged car battery should be around 12.6.-13.8 volts.
Can you charge a car battery overnight?
Yes, but it depends. You can charge it overnight if you have an automatic charger that shuts down power when the battery is fully charged. Otherwise, don't charge, especially if you have a fast charger. Else you risk overcharging and possibly blowing the battery.
How long does it take to charge a dead 12V battery?
Depending on the charger amperage, a dead 12V battery charge time can take between 10 to 24 hours to get fully charged. If you just want a boost to start the engine, it should take about 2 to 4 hours to charge.
How do you read a 6 amp battery charger?
A 6 amp charger is a charger set to deliver 6 amperages to the car battery. The charger may come in 0 to 12 amps but can be set. In the amp meter, the numbers above the cube box represent the amps the battery is delivering. There is also a place having 0 to 100% indicating how much charge your battery has.
The small red triangle from Zero to a particular cube indicates how much amp the charger passes to your battery. So, on a 6 amp battery, the small red triangle should pass from 0-6. You can search more if you want to know how to read battery charger amperage and the performance of electric car charger for charging EV.
Conclusion
This article has explained that if you have a drained battery and are wondering how long to charge a 12v car battery at 6 amps. It typically takes 4 to 10 hours, depending on the charge left, battery size, battery type, and battery conditions.
When charging batteries be careful not to use a battery charger whose amp is too high for your battery capacity. Too much fast charging is usually a way of reducing your battery life. Also, avoid overcharging your charger, As doing this puts your battery at risk of exploding. Be watchful. If your charger does not have a feature to notify you when your battery is fully charged.