What is The Maximum Charging Voltage for a 12 Volt Battery: Amps, Full Charge and Power Supply

As we need batteries for daily activities, it is necessary for us to know the basics of it and how to maintain it properly. Therefore it is important for us to know terms such as amps, volts, and how they are applied to batteries. For this reason, we will be discussing them today, in specific things related to amps, full charge, and power supply for a 12 volt battery.

How many amps do you need to charge a 12 volt battery?

Before we delve into details regarding the amount of amps needed for a 12 volt battery, let us differentiate amps and volts first. In simpler terms, volt, or voltage, is the amount of pressure that’s needed to let the electrons flow. Meanwhile, amp, or amperage, is the amount of electrons itself.

Let’s use a river as an example for amp and volt. Volt is basically the speed or steepness of the river, while the amp is the amount of water the river has. So if there is a small waterfall with a trickle of water, the water would be the amperage, while the speed and position of the waterfall is the voltage. The trickle poses no danger since the amount is little, but if the amount is large, it can be threatening since you can drown in it even when the speed is slow. From here, we can learn how amperage plays a big role and should be measured carefully.

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Now here comes the main part: how many amps are needed for charging if we have a 12 volt battery? Manufacturers have provided a formula that allows us to measure the amp easily. Using the battery’s capacity (ah and volt). They recommend us to have 25% of the battery’s capacity. For example, we have a 100 ah and 12 volt battery, so we will need 25 amp for the battery, as 25 is the 25% of the ah.

This does not mean that the chargers cannot be larger, or course. If you would like to decrease the amount of charging time, larger chargers are allowed. However, it should be noted this method poses the risk of decreasing the battery’s life. We can also use smaller chargers, but it will eventually burn up as it takes longer to charge the battery. To avoid all the unnecessary trouble, it is best to use chargers that do not pose a risk for the batteries, and those chargers must be in line with the formula provided by the manufacturers.

What voltage should a 12 volt battery read when fully charged?

Believe it or not, but a 12 volt battery should not be read with 12 volt to see if it’s fully charged or not. In fact, 12 volt is just a term used to distinguish one battery from another. In reality, the amount is not exactly 12 volt. Thus, the volt should be read in another number to know if it’s fully charged or not.

When we charge the batteries, we should bring them up to at least 14 volts to have them fully charged.

For example, wet-cell batteries would need at least 14 volts reading to distribute the electrons equally all around the battery. After the electrons distribute themselves though, the volt will balance itself out to 12.6 volts.

Of course, different conditions would apply to gel-cell batteries. As a matter of fact, gel-cell batteries should not be charged no more than 14.1 volts (although it also depends on the manufacturers). It should be noted that the reading cannot be applied universally. Different kinds of batteries would have different readings when it comes to fully-charged batteries.

Sounds easy, isn’t it? However, there are some things we must do if we want to get accurate reading of the battery when it’s fully charged.

First, the battery should be in a rest state. Rest state means that the battery should not be attached to any power supply.  Manufacturers recommend a 24-hour resting time, but a couple of hours should be sufficient.

You can also check the battery’s current energy during charging. If you need a chart, don’t worry, because these “voltage landmarks” can help you guess the approximate amount of energy the battery has at certain volts. Below is the landmark:

11.4 volts means 20% charged

12.3 volts means 50% charged

12.5 volts means 70% charged

12.6 volts means 100% charged

The landmarks are useful for you to know how much energy should be given to the battery. It can also help you  to measure the time needed to charge the battery.

With all the information provided here, you’ll be able to get accurate reading of your battery when you need it.

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How do you charge a 12 volt battery with power supply?

Charging batteries with power supply isn’t hard, but it requires some extra work. First, you need to calculate the charging voltage and adjust it to the number of cells, and then set the voltage you need.

For example, if your voltage limit is 2.40 volt, you will need to set the voltage to 14.40 volt. After that, you can select the current of the charge and adjust it to the battery’s size. The size depends on the type of battery. If the batter is lead acid, it would be ten to thirty percent of the rated capacity.

Charging a 12 volt battery might take quite some work, but it can be done if you do it properly. You need to make sure that the charger is in the right volt, and you have the proper reading of the battery. It should be noted, however, that the type of battery also affects the charging process and volt. It might take quite a while to adjust to the process, but once you’ve done it, you’ll get accustomed to it easily. Are you ready to charge your 12 volt battery properly?