The other day, my home had power-outage for like 6 hours. I could go buy a UPS (Uninterruptible Power Supply), or I can make my own UPS using a car battery.
Well, I am just hoping this DIY UPS lasts 6 hours so I can keep using my spare laptop, which shouldn’t need that much power anyways to run off the UPS. But if I tried to run my desktop PC, it’d probably last only 2-3 hours at most, maybe even less.
This DIY is for 220 Volts so you will have to make some calculations to make sure you are providing the correct number of invertors and etc…etc… Btw, if you do use it for powering up your laptop, you don’t need an invertor as most laptops are around 12VDC anyways, which is what car batteries are at. (But you will need to hack an adaptor to the laptop for sure)
In this article we look at how you can cobble together a 220 Volt power supply using components you can buy at your local automotive store. But first it is important to understand a few basics about batteries, and how to convert 12 Volt DC battery supplied electricity into 220 Volt AC current that your household appliances can use.
A twelve Volt battery is a storage device that, when charged, stores electricity in chemical structures that can reverse and release electricity if required. Batteries are typically rated in Amp Hours (AH) – ie how many Amps for how many hours the battery will perform. An inverter is a device which can take the DC current from a battery and convert it into 220V AC current for your appliances.
To calculate how many batteries you need, and how big an inverter is quite simple. Investigate the specification plates on the back of each appliance. In the case of my laptop, the power supply is a 90W unit.
For an inverter one can work on a rule of thumb that to produce 100W will require approximately 10 Amps, hence in reality the lap top requires about 10 AH of battery life per hour. With a 90 AH battery one can therefore expect about 9 hours of power before the battery provides too little current to keep the inverter going. But it is not this simple.