How to calculate inverter battery backup time : Before buying an inverter battery, it is very important for you to know how much backup the battery will provide. Because we have to buy the battery so that when the power goes out, your load can run continuously with the inverter battery.
But many people make the mistake of buying a battery without thinking. Later they have to regret because their battery does not give them the backup they need. They think that their battery is bad. So that is why you should calculate it before buying an inverter battery and choose the battery on this basis.
How many Solar Panels Required to Charge a 150ah Battery
How to Calculate Battery backup for solar system
In the market, you get to see batteries of different sizes and different technologies. So if you run the same load on all those batteries, you will not get the same backup time, because it will depend on its technology how much backup you will get.
Most of the batteries available in the market are of C20 rating. These are made to run low load for a long time. You should run a load of up to 200 watts on this type of battery. If you run a load of 200w on a 150ah@c20 rating battery, then this battery will give you a backup of about 3 hours.
Similarly, if you run a load of 200 watts on a 150Ah@c10 rating battery, it will give you a backup of around 4 hours. This is because the battery supports high charging and discharging current. So, if you run a load of up to 200 watts at 20 volts, there will be no negative impact on its performance.
Similarly, if you run a load of 200w on a 100Ah lithium battery, then that battery will also give you about four hours of backup, but here you will see that despite the lithium battery being only 100Ah, it can give backup equal to a lead acid battery of 150Ah @ C10 rating.
Because lithium battery is much more efficient than lead acid battery. Due to which you get more battery backup in it.
Battery Backup Time Calculation Formula
Well if you want to calculate the battery backup with the help of a formula, then the formula for its calculation is given below, but this formula will not work practically, because practically you cannot tell how efficient your battery and inverter are.
If the power factor of your inverter is 0.7 or less, then your inverter will lose a lot of power due to which your battery backup will become less, even if you install a lithium battery, you will still get less battery backup.
Formula
Backup time (in hours) = [ Battery rating (in Ah) × Battery rating (in V) × Number of Batteries × Battery Efficiency ] / Load in Watts (W)
Backup time (in hours) = 150 x 12x 50% / 200w
H = 1800x 50/100 / 200w
H = 900/ 200
H = 4.5 h
So this way you will see that a 150 Ah battery will give you around 4 hours of backup if you run a load of 200 watts.
If you look at it in units, you will get approximately 0.8 units of electricity from a 150Ah battery.
If you want to choose the right battery, you can use the solar calculator given on our website where you can enter your load and the duration of backup you need. By filling this information, you can get the right solar inverter and battery for yourself.
