# Battery Charge Time Calculator-Calculating, Time and Advantages

Jul 10, 2020   Pageview：95

Batteries are very essential in our everyday survival. We need them to power our gadgets such as phones, laptops, watches, cars, and even houses. For this reason, every detail such as charge time is very important because they help us plan. But the problem is batteries have different charge times making it difficult for us to guess. Other factors can affect the charging rate of the battery.

For instance, if you use the wrong charger then it might take you some extra hours than the normal to charge the same battery. Battery charge time refers to the total time a battery takes before charging fully.

How do you calculate the battery charging time?

Calculating battery charging time is easy.  Some formulas aid in calculating battery charging time. We are going to discuss one of the simplest formulae that you can use. Besides that, some websites offer a quick solution to this by providing you with a free battery charging calculator.

You are only required to have some specific values for your battery such as the battery capacity and charge rate current. Note that some devices have inbuilt battery charging time calculators that make the work easy. For example laptops, phones, and even some cars. They come pre-loaded with a BMS that displays the charge time automatically on your screen.

Low Temperature Large Current 24V Emergency Starting Power Supply Battery specification: 25.2V28Ah (lithium battery) , 27V300F (supercapacitor pack) Charging temperature：-40℃~+50℃ Discharging temperature: -40℃~+50℃ Starting current: 3000A

Let's look at an example by calculating the battery charging time of a lead-acid battery. Let’s use the following formula.

Charging time = Battery Ah /Charging current. I.e. T=Ah/A

T= Time in hours

A= current in amperes

Ah= ampere-hour rating of a battery

The first step is to calculate the charging current. This should be 10% of the battery Ah.  So our charging current will be, 120 Ah x (10/100)?=12 Amperes. However, because of some losses we are not going to use 12 but 13 or 14. Let’s take 13. So our charging time will be 120 / 13 = 9.23 Hrs.

However, since there must be about 40% loss when charging we need to replace it by following these steps. 120 x (40 / 100) = 48. Then we add the losses. 120 Ah + Losses (120 + 48 = 168 Ah). 168 / 13 = 12.9. So it takes 13 hours to charge a 120 Ah battery to a 100% on a 13A current.

How long does it take to charge a battery charging time?

Batteries have different charging times because they hold different power. Also if your battery is much discharged then it will take more time than the one that is a little discharged. It will take 12 or more hours to charge a battery that has been severely discharged.

Low Temperature High Energy Density Rugged Laptop Polymer Battery Battery specification: 11.1V 7800mAh -40℃ 0.2C discharge capacity ≥80% Dustproof, resistance to dropping, anti - corrosion, anti - electromagnetic interference

You should not continue charging a battery that is overheating. This can cause fatal accidents. So if you feel that the battery is hot when you touch it, then you have quit. On top of that, you should consider charging your batteries at a slow charge rate. For example, 10 A is considered as slow charging while 20A and above is considered an as fast charge.

Fast charge is not recommended because it reduces the lifespan of a battery. Before determining the battery charging time, you have to determine the capacity. You can easily find this info by looking at the manufactures specs. Then multiply that capacity by 0.6 which is the standard reserve capacity. The next step is measuring the open-circuit voltage. You do this by simply using a voltmeter

Replace the battery by 36 amp hours if you normally use the 10A rate. Not that the chargers do not output exactly 10A. So your battery may last more than 12 hours on the charger.  Wait for the battery to cool and measure it again using a voltmeter to confirm whether it's fully charged. Then look up the charging time by using your open-circuit voltage.

Always wear protective gear while you are charging and discharging batteries. As we have discussed the charging time of a battery can be affected by the following factors.

• Temperature

• Capacity

• Charger type e.g.  Fast or slow

• Charge state. E.g. Discharged, partially charged or fully charged

If all these calculations are hard for you to grasp, then you can use an online calculator. As long as you can tell the capacitance of your battery, charging rate, and charge state then a calculator will be the perfect solution for you.

What are the advantages to use a battery charge time calculator?

Using a battery charge time calculator has so many advantages. First, it's very easy to use than going the manual way. You can get your battery charging time by just inserting some values. Leave the other work to the calculators. . Another notable advantage is that using a battery charge calculator saves time. Not so many people can afford to waste their time on calculations every time they are in search of battery charge time.

A battery charge time calculator is also more accurate than calculating the old-school way. It's easier to make errors when calculating manually than using the manual way. Also, the calculator makes work a lot easier. For instance, when you are trying to calculate the battery charge time for many batteries. If you decide to calculate the old fashioned way then you will end up consuming a lot of time and most probably making a lot of errors.

Final thoughts

Knowing the battery charge time is very crucial because it helps you maintain good care. Monitoring the charge time also helps to understand the behaviour of your battery. So you will know when it has started degrading so that you can prepare yourself to buy another one. There are two ways in which you can use to find the battery charge time. By calculating it manually or by using a battery charge time calculator. Both ways are effective but using a calculator is easier. It's very hard for you to make mistakes by using a battery charge time calculator. Also if that you are dealing with so many batteries the calculator is the best way to go.