How long does Inverter last

How long does Inverter last

How long does Inverter last

The Lifespan of a battery depends on the type and how well you look after them. How many days of power depends on what you are powering, how long, and then on the size of the battery bank. With lead-acid batteries, rated capacity changes with current draw and time rated at the 10 or 20hr rates. usable capacity is always under 50 percent of the total rated capacity for lead-acid types.

If you are planning to buy a new inverter that lasts long or upgrade your old one; whatever may be the reason, it is very important to understand what is the right inverter for your home. The power requirement at your home can be different from your neighbor’s home, so do not just install the same inverter (in terms of power) in your home. Before buying an inverter for your home do a little homework and understand the basics, as inverters are only as durable as the workload given to them.

The inverter comes in a different power rating. Suppose you have bought the 1KVA inverter 12VDC (1KVA means you can put a maximum 1KVA load on it and 12VDC means use a 12V battery to store the energy). If you use a 12V/150AH battery, it can store up to 1800 KVA energy. But the power which we are using at home comes in the form of AC. So, we have to convert DC power into AC power by using the below formula:

KW (Power in AC) = KVA (power in DC) x Power factor

(Generally, all inverter comes with power factor 0.8 or 0.9)

KW = 1.8x0.8= 1.44 (1440 watt)

Therefore, you can use 1440-watt power in AC. So, if you put 2 lights of 50W each and 1 fan of 100W on the inverter, total power will be 200W (50+50+100) and you will get a backup hour up to 7 hours (Backup time = 1440/200 = 7.2 hours. = 7 hours 12 min)

Building an inverter for home purposes is very common these days due to emergency purposes. But how long the batteries last, does not depend on the inverter; it mainly depends on the type of battery that you are using and how many hours you are using it. Therefore, it mainly depends on battery type, capacity, and usage time. To know how long batteries last cannot be answered without knowing the size of the battery bank and the load to be supported by the inverter. The first step is to estimate the total Watts (or Amps) of the load, and how long the load needs to operate. This can be determined by looking at the input electrical nameplate for each appliance or piece of equipment and adding up the total requirement. Some loads are not constant, so estimations must be made. For example, a full-sized refrigerator (750-Watt compressor), running 1/3 of the time would be estimated at 250 Watts-per-hour. After the load and running time is established, the battery bank size can be calculated. The first calculation is to divide the load (in Watts) by 10 for a 12-Volt system or by 20 for a 24-Volt system resulting in the number of Amps required from the battery bank.

Load Calculations

Suppose you were to run a microwave oven for 10 minutes a day, which draws about 1000 Watts, despite their size, to keep it simple, think of the inverter as electrically transparent. In other words, the 1000 Watts required to run the oven come directly from the batteries as if it were a 12 VDC microwave. Taking 1000 Watts from a 12-Volt battery requires the battery to deliver approximately 84 Amps.

(1000 Watts ÷ 12 Volts = 84 Amps)

A full-sized refrigerator draws about 2 Amps at 120 Volts AC. By multiplying 2 Amps x 120 Volts, you find out the refrigerator uses 240 Watts. The batteries will need to deliver 20 Amps to run the refrigerator (240 Watts/12 Volts = 20 Amps). Typically, refrigerators operate about 1/3 of the time (1/3 "duty cycle"), or 8 hours a day. Therefore, the AH drain will be 160 A.H.

(8 hours x 20 Amps = 160 A.H.).

After the load and running time is established, the battery bank size can be calculated.

Choosing the Right Number of Batteries for your inverter

This is a little more difficult due to the rating method used by battery manufacturers. Also, because of the nature of the battery, the higher the discharge rate, the lower the capacity of the battery. Most batteries' A/H. capacity is stated for the 20-hour rate of discharge. This means that a battery has a 100 A.H. capacity if it is discharged over 20 hours, or at about 5 Amps-per-hour (100 A/H) ÷ 20 hours = 5 Amps DC). However, this same battery would last only one hour if the discharge rate was 50 Amps-per-hour (50 Amps DC x 1 hour = 50 A.H.) because of the high rate of discharge.

Finally, two more items must be considered. The more deeply the battery is discharged on each cycle, the shorter the battery life will remain. Therefore, using more batteries than the minimum will result in a longer life for the battery bank. Keep in mind that batteries lose capacity as the ambient temperature lowers. If the air temperature near the battery bank is lower than 77°F (25°C), more batteries will be needed to maintain the required capacity.

How to Improve Your Inverter

To have a long-lasting inverter battery, you should be focused on these two aspects:

1. Decrease the Load: By decreasing the load, you directly improve the backup time. Less load means fewer appliances, which means that your inverter will be able to power those lesser appliances for a longer time. If you are sitting in one room then maybe you only need one fan and one tube light at that particular time, make sure to switch off the appliances of other rooms so the inverter has a minimal load.

2. Get Bigger Sized Inverter Battery: If you want to power more appliances in your home then you would want a battery with more capacity. More capacity would allow you to put a heavier load and hence you’ll get much longer backup time.

3. A battery rated at 100Ah will have less capacity as it gets older. After two- or three years’ use, its capacity will be reduced by 20–50% depending on how it has been used and recharged. A battery tester will measure capacity.

Hopefully, this article has been helpful towards your understanding on how long an inverter battery lasts? Backup time is calculated and how you can get longer backup time. In most cases, you’ll have an estimated backup time displayed on the inverter but it is always a good idea to do some calculations while you are planning to buy a new inverter battery.

Kindly Contact us for more information about Inverters 

1st Dec 2020 Ernest Orhuebor

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