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.

[via] scienceinafrica

Fed up with wired headphones, but your device does not have Bluetooth? You can get Bluetooth headphones that have an adapter but normally that are not normally very good as they are normally made with low capacity components but this transmitter by iBluon offers a good quality audio, plus great battery life from the internal battery.

The device connects using the Bluetooth 2.0 A2DP/AVRCP which if you have the same in headphone then they will connect no problem, and last for around six hours on playback or over a hundred hours on standby.

Features:

6 hour playtime
120 hour standby
Bluetooth 2.0 compliant
A2DP/AVRCP
Extension cord included
USB cable included for charging

Source [Tech Digest]

Check out this howto on doubling your battery life by replacing a linear voltage regulator (the thing that converts DC voltage, e.g. from 12V to 5V) to a switching regulator. Switching regulators are way more efficient than your typical off-the-shelve crappy regulators such as 7805 which get too hot too fast. Get the Dimension Engineering regulators here. This howto could easily be applied to any other device, not just radio stuff…

I first got the idea for this over on the thread for the DX6/7 on RCGRoups.com forums. I run nitro cars, so I bought a DX3. I used the radio for a while, and my battery life was on the better side of most radios–but the DX7 owners were getting like 5-6 hours of runtime after the mod. Now that’s what I’m talking about! I figured that the DX3 and the DX6/7 might be using the same regulator chip, due to the fact that the chip design and internal circuitry shoulden’t have changed that much. Less PCB tooling and all that.

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Wow, this is some great stuff…i am jealous…hehe… I need 3G…noW!!!

I’ve received my (Cingular) Samsung Blackjack and here’s a video that shows what’s in the box. After a full charge and a few problems with the service activation (Amazon screwed it up, apparently) I got the thing up and running with UMTS (3G) data connect. After a couple of hours, my first impression is that it blows the pants of my Treo 700w in virtually every aspect. I’m currently testing the battery life so keep an eye on Ubergizmo because the full review is coming up soon.

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