**What is battery life?**

#### “Battery life” is **the amount of time a device runs before it needs to be recharged**. “Battery lifespan” is the amount of time a battery lasts until it needs to be replaced. One factor affecting battery life and lifespan is the mix of things you do with your device.

**Battery life calculation formula:**

#### The life of the battery B_{(h)} in hours is equal to the total capacity of the battery Capacity_{(Ah)} in Amps hours divided by the output current taken from the battery I_{(Ah)} in Amps hour. Hence the battery life calculation formula will be

**Battery**_{ (h)} = Capacity_{(Ah)} / I_{(Ah)}

_{ (h)}= Capacity

_{(Ah)}/ I

_{(Ah)}

#### Also you can convert the battery life in days, months and years. Here the formula will be

**Battery**_{ (day)} = Capacity_{(Ah)} / 24 x I_{(Ah)}

_{ (day)}= Capacity

_{(Ah)}/ 24 x I

_{(Ah)}

**Battery**_{ (month)} = Capacity_{(Ah)} / 30 x I_{(Ah)}

_{ (month)}= Capacity

_{(Ah)}/ 30 x I

_{(Ah)}

**Battery**_{ (year)} = Capacity_{(Ah)} / 365 x I_{(Ah)}

_{ (year)}= Capacity

_{(Ah)}/ 365 x I

_{(Ah)}

#### Sometimes, you may do not know the output current; hence you can calculate the battery output by below formula

**Load current (Amps- Hour) = Total Load (W) / battery Voltage (volts).**

**I**_{(Ah)} = P_{(W)} / V_{(v)}

_{(Ah)}= P

_{(W)}/ V

_{(v)}

#### Here the load current I_{(Ah)} in Amps hours is equal to the total load P_{(W)} divide by the battery voltage V_{(V)} in volts.

#### Hence the battery life formula can be written as,

**Battery**_{ (h)} = Capacity_{ (Ah)} / (P_{ (W)} / V_{(v)})

_{ (h)}= Capacity

_{ (Ah)}/ (P

_{ (W)}/ V

_{(v)})

** = V**_{ (v)} x Capacity_{ (Ah)} / P_{ (W)}

_{ (v)}x Capacity

_{ (Ah)}/ P

_{ (W)}

#### The battery life is equal to the battery volts times of the battery capacity divided by the total loads.

#### Hence, while increasing the load, the battery life will be reduced.

__Example:__

__Example:__