How can I adapt the power of my battery or my series of battery, depending on the choosen inverter?

A battery or battery block allows you to make the best use of the chosen inverter.

To choose the right battery or battery block, you need to know how much power (watts), absorb the products you want to plug in, and for how long you want to use them.

The table below highlights, for batteries that provide 12 Volts DC, their capacity and energy absorbed in time, as well as the time of use. By using 24 Volts DC batteries, the usage time is doubled.

  50Ah 75Ah 100Ah 200Ah 400Ah
50 W 9 hours 14 hours 20 hours 40 hours 80 hours
100 W 4 hours 7 hours 10 hours 20 hours 40 hours
200 W 2 hours 3 hours 4.5 hours 10 hours 20 hours
300 W 1.3 hours 2.2 hours 3 hours 6 hours 12 hours
400 W 1 hour 1.5 hours 2 hours 4.5 hours 10 hours
600 W - - 1 hour 2.5 hours 6 hours
800 W - - 50 minutes 2.5 hours 4 hours
1000 W - - 40 minutes 1.5 hours 3 hours
1500 W - - - 30 minutes 2 hours
2500 W - - - 12 minutes 48 minutes

This table is given as an example and it is not guaranteed that it is accurate in all cases. Multiple external events, e.g., peak power, temperature, load state, battery conservation and use, may influence the usage time.

 

Practical case

Connected devices

By adding the daily consumption of each device, you obtain the total daily energy required.

In our case: 660+250+150+270=1330 Wh

With the formula Watt/Volt = Ampere, you deduct the total daily intesity required.

With a 12 Volts DC: 1300/12=110,83 A. You therefore need, at minimum, a 110 Ah battery.

If all these devices are used at the same time the consumption will be 1560W.

As a minimum multiplier factor of 3 is required to choose the best-adapted inverter, it is therefore necessary to provide a 4500W inverter.

With a 12V battery you will need a capacity of 400Ah and with a 24V battery you will need a capacity of 200Ah.

22'' LCD TV
Consumption: 220 W
Usage time: 3 hours
Total consumption per day: 660 Wh

Microwave oven
Consumption: 1200W, set to half power
Usage time: 5 minutes, 5 times per day
Total consumption per day: 250 Wh

DVD Player
Consumption: 50W
Usage time: 3 hours
Total consumption per day: 150 Wh

Laptop computer
Consumption: 90 W
Usage time: 3 hours
Total consumption per day: 270 Wh
 
 
Choose a battery or a battery block that is able to provide you with more power than you need, so as not to completely discharge the battery.
 
 
Periodically check the battery or battery block efficiency to avoid problems you may encounter while using the inverter.
 
 
When you change one or more batteries in the battery block, you have to change them all. Do not mix new and old batteries. In addition, it is very important to charge each battery separately and then connect the cables to the battery block.
 
 
With a very high power, a specific accumulator must be used (a secondary accumulator) for this use. The compatible batteries are those called AGM (e.g. motor-homes batteries), because they provide maximum energy at 12 Volts voltage.