# Online calculation of battery charging time

Batteries are so tightly embedded in our lives that we use them every day in mobile phones, wireless devices, flashlights and more. In addition, people often transfer devices that run on finger batteries to rechargeable ones. Also, in areas with unstable electricity supply, uninterruptible power supply systems are often installed.

Uninterruptible power supply systems in their simplest form consist of:

• Charger
• rechargeable batteries;
• inverter;

If the system is powered by alternative energy sources, for example, from a solar battery or a wind turbine, a specialized controller is installed to charge the battery. And in this case, it is important to calculate the time of their charging in order to select the optimal power sources within the time available for the availability of alternative energy.

Drivers also have to charge car batteries, especially during the cold season, if they are worn out.

In all these cases, it is convenient to use “smart” charges that will disconnect it from the power supply when the desired charge level is reached, and also select the current in accordance with the type of battery. But how to calculate how much battery you need to charge? To do this, simply use our online calculator to calculate the battery charging time:

MAh battery capacity
MAh charging current
Charging time
(hour)

To perform the calculation manually, you need:

1. Find out the battery capacity.
2. Divide it by 10.
3. Multiply the result by a factor that takes into account the efficiency of the memory and battery characteristics - usually it is in the range of 1.2-1.6.

As a result, you get the battery charging time. It is recommended to select current 10 times lower than the battery capacity. But often this does not provide a fast charge, if you need to do this, you can find out the charge time with an arbitrary current.

Our online calculator will produce a result in a couple of clicks. But if you want to calculate the charging time yourself, pay attention to the formula:

t = k * (C / I)

Chronic under- or overcharging of batteries significantly reduces their service life in the flesh before an explosion, such an outcome is likely with an incorrectly selected current and time. Therefore, pre-check the data for each specific situation, and also take into account information from datasheets on products.