How To Charge A Car Battery With A Laptop Charger?

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The urgent need to charge a car battery is occasioned by the battery’s low voltage, which inevitably leads to its inability to kick start the car as expected.

There are various ways via which we can charge a car battery, which underlies how important the procedure is to all motorists, such as by the use of electricity at home, with the aid of an inverter, by jump-starting the battery, and many more.

This wide range of charging procedures is meant to provide us with easily and readily available options for keeping car batteries alive and useful.

But, how can we charge a car battery with a laptop charger? This question, along with many others related to it, shall be answered in the course of this article. (Read Also:How To Charge Car Battery With DC Power Supply)

How To Charge A Car Battery With A Laptop Charger? Yes, a car battery can be charged with the aid of a laptop charger. However, to do this successfully requires certain mandatory tools such as a 12 Volts car battery, a multimeter, digital voltmeter, jumper cables, and a 10 to 17 Volts laptop charger.

Note that, though ordinary wires can work just as well as jumper cables, jumper cables are preferable for their general safety in the procedure. Having assembled all the necessary tools, you may then proceed according to the following steps meticulously.

Table Of Contents

How To Charge A Car Battery With A Laptop Charger With Steps

Step 1.

This step involves the careful connection of the electrical circuit. In the beginning,  you should crimp off the DC jack from the laptop charger, even though you can also use the DC jack as it is.

The outer metal casing of the DC jack is its negative terminal while the small hole inside it is the positive terminal. The positive wire goes through the multimeter because that will show you the current reading on the multimeter,  for ease of monitoring your progress.

To successfully establish the circulatory for charging with a laptop charger, you may have to refer to easily obtainable schematic diagrams online. Good and reliable laptop chargers such as the 65 or 45 Watts laptop chargers for HP Chromebook can be obtained from Amazon

Step 2.

After successfully setting up the circuit as required, the battery will start charging, but to be certain of this, you should closely monitor the readings on both the multimeter and voltmeter.

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Step 3. 

The length of time the battery takes to charge fully depends on such factors as the power of the laptop charger, the status of the battery, and so on. However, despite this, it may take anything from four hours to get your battery fully charged to about 12 Volts upwards. (Read Also: How To Charge Multiple 18650 Batteries)

In this step, when you observe the battery is fully charged, you can then proceed to disconnect it from the charger. Batteries that enjoy remarkable commendation and great multiple stars customer reviews, such as Delphi BU 9094R MaxStart AGM Premium Automotive Battery, Group Size 94R( Reversed Terminal) can be easily purchased from Amazon. (Read Also: How To Open BMW Hood With Dead Battery)

Can You Charge A Car Battery With A Laptop Charger?

Sure you can, but to do so effectively, you must take into cognizance the specification or capacity of your battery, the power of the charger, and also execute the setting of the circuit carefully and correctly. This is mostly because different batteries have different fits of chargers suitable for them and you will do well to get that charger that is the correct fit for your type of battery.

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Are There Any Challenges To Charging A Car Battery With A Laptop Charger? 

Yes, there are certainly avoidable risks. These risks result from the possibility of overcharging the battery in the process. It is for this reason that you are advised from the beginning to always incorporate the use of a multimeter throughout the procedure. (Read Also: How To Charge A Car Battery While Still Connected)

This will enable you to monitor closely any currency fluctuation or changes as you charge the battery. When you overcharge the battery, it may produce explosive gases which will eventually damage your battery permanently. To avoid this, monitor the current and make sure that the voltage of the battery does not exceed 12 to 13 Volts at most.

How Long Does It Take To Fully Charge A Car Battery With A Laptop Charger? 

How long it takes to fully charge a car battery with a laptop charger depends on several factors such as the quality or ratings of the charger, the voltage or capacity of your battery, the degree of draining in the battery, and so on. (Read Also:Can I Use Jumper Cables For Inverter?)

However, all things being equal, it will take between one to a couple of hours to get your battery fully charged using a laptop charger.

How Does Charging  Car Battery With A Laptop Charger Differ From Other Methods Of Charging?

This method of charging car batteries with the use of a laptop charger is slightly different from most others because, if you insert a multimeter in the circuit, you will be able to frequently monitor the process and thus avoid overcharging. (Read Also:Can A Bad Battery Make Your Computer Slow?)

Overcharging in batteries has different implications depending on the type of battery. For instance, with lead-acid batteries, any saturated or full charge will prevent sulfation and hence allow the battery to retain its voltage for long periods. With nickel-based batteries, on the other hand, overcharging will make the battery too hot which may lead to premature damage. (Read Also: How To Charge A 12Volt Battery From A 24Volt System)

When you charge your car battery with the aid of a laptop charger, you more or less eliminate these risks to your battery as against most other means of charging the battery.

Lithium-based batteries equally benefit a lot from this method of charging since any random charging does not affect them in any way. In fact, lithium batteries even prefer lower voltage limits which you can easily accomplish with a laptop charger.


Does Charging A Car Battery With A Laptop Charger Has Any Effect On The Battery? 

Yes, it does profoundly. This is because, when the charging of a car battery with a laptop charger is executed correctly, you will not only prolong its life span but also improve its voltage retaining capacity and efficiency by preventing excessive sulfation and overheating.

Other methods of charging a car battery may not necessarily have these advantages, a factor made possible due to effective monitoring of the entire process, from start to finish, with the aid of a multimeter in the circuit.

How Do You Make Charging A Car Battery With A Laptop Charger More Effective?

You can make car battery charging with a laptop charger more effective through proper charging and storage of the batteries. For example, by charging your car battery with a laptop charger, you can regularly top up your battery voltage once in a while in each of its cells,  which will prevent sulfation by maintaining the cells at a charge of not less than 2.05 Volts in each cell. (Read Also:Will A Bad Battery Keep A Laptop From Turning On?)

Car battery voltage retaining capacity and long life is also enhanced when you store the batteries at the correct temperatures in cool environments. This proper storage makes your charging much more effective and long-lasting.

How Do We Charge A Car Battery Without A Designated Charger?

Car batteries can be charged manually with a power supply featuring adjustable voltage and current limiting. The deliberate use of the word ‘manual’ is meant to underlie the need to know how to go about the entire process and also to never leave the process unattended to especially since it is not automated.

This is occasioned by difficulties in detecting full charge, particularly with nickel-based batteries,  and hence manual charging should be limited to only lead and lithium-based batteries.

Charging Lead Acid Batteries

Preliminary to charge any lead-acid battery, calculate its voltage according to the number of its cells in series and thereafter, set the voltage and current limits accordingly. (Read Also:Does Bluetooth Drain The Battery On A Laptop?)

For a 12 Volts lead-acid battery with six cells set the voltage to about 14.40 Volts, which translates to 2.40 Volts per cell thereby giving you 14.40 Volts in total. You should also select the current range with due consideration to the size of the battery, which for lead-acid batteries is between 10 to 30 percent of its rated capacity.

As you go about the process, observe the temperature of the battery, its voltage, and current during charging, preferably in a well-ventilated and aerated room and at ambient temperatures too. The moment the battery is fully charged, the current will drop to about 3 percent of the rated Ah.

You are also advised to disconnect the charging after about 16 to 24 hours if the current has bottomed out and hence cannot go any lower. Note that, high self-discharge can prevent the battery from reaching its low saturation level. For float charge operational readiness, you may lower the charge voltage to about 2.25 volts per cell.

Charging Lithium-Ion Batteries

These batteries charge in much the same way as lead-acid batteries and as such, caution is necessary for the use of the power supply. Check and ensure that the full voltage is about 4.20 Volts per cell before setting the threshold accordingly. (Read Also:Does Battery Voltage Drop When It Discharges?)

Furthermore, make certain that the cells connected in series do not exceed this voltage. To do this properly, the protection circuit, which is provided in the commercial packs, will help you out. When the cells reach about 4.20 Volts each and the current has dropped to about 3 percent of the rating, the battery is fully charged. Thereafter, disconnect the battery and ensure that no cell dwells at 4.20 Volts for more than a couple of hours.

Charging NiCd And NiMH Batteries

Charging nickel-based batteries is a wee bit more challenging because its full charge detection is determined by a voltage signature that varies with the applied charge current.

To charge a nickel-based battery with a regulated power supply, you are advised to use a temperature rise on a 0.3 to about 1C  rapid charge as an indication of full charge. In case you are charging at a lower current, estimate the level of the remaining charge, and also calculate the charging time.

About 3 hours of charging time will suffice for an empty 2 Ah NiMH battery at a rate of between 750 to 1000 mA to be fully charged.

How Do We Use, Maintain And Dispose of Car Batteries? 

Topping the charge of a battery occasionally helps to prevent sulfation as well as maintain battery voltage, especially with lead-acid batteries. However, regardless of everything, we must never incinerate a  battery in open fires, as this is liable to cause the battery to explode with obvious consequences to yourselves and others in the vicinity.

Similarly, we must always wear gloves when handling batteries since there is the likelihood of coming in contact with its corrosive electrolyte. However, where there is exposure to our skins, flush the affected part(s) with clean running water immediately.

If there is any exposure to the eyes, flush with clean water too for about a quarter of an hour, and thereafter, seek the help of a qualified physician without delay. 

How To Charge A Car Battery With A Laptop Charger – Conclusion

Good batteries mean satisfactory motoring at all times and for this reason, a lot of research has been conducted to make them more durable and fast to charge. In the same vein, various methods of car battery charging have been profounded to make sure that you will always be catered for when it comes to battery-related worries.

Through multiple methods of battery charging are available, you are however advised to choose that which will not harm your battery and which you can execute at a moment’s notice.

Alongside this consideration, we have taken it upon ourselves to introduce to you highly rated car batteries, as well as good and reliable laptop chargers,  that will serve you most satisfactorily and also where to get them for instant purchase.

Since batteries use corrosive electrolytes, we have equally not treated safety measures with any levity. The depth and quality of information contained herein, is a must-have for all motorists,  just in case.

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