# Sunday, 01 July 2007

Here's another post which I found hiding in my Live Writer drafts.. seems like I keep forgeting to take the pictures of a few items in the post, this was typed after the Johor floods... damn.. I think that was about half a year ago...

We had some particularly bad weather in some of the states here in Malaysia. There was very major flooding in several states and a lot of people were displaced from their homes. While I was reading through the stories in the paper one of them mentioned that the people who were evacuated were unable to contact their families not because the cellular infrastructure was down but because they ran out of power on their cellphones.

As someone who has been searching for the best portable power solutions, let me just list out a few of the portable power solutions that I have acquired and you too can use if you feel the need to keep that gadget of yours powered.

Portable 5V Battery Pack / Power Source

The first thing I'd like to show is the portable 5V battery pack, why do I call them portable 5V packs? Because that's what they provide, no matter what they call themselves, either portable handphone chargers, portable Nintendo DS chargers, portable PSP chargers. It's very likely that they're supplying 5V of DC current which is the standard current used to charge the ~3.7 volt DC battery which your device uses. Some of these types of packs come with rechargable batteries inside, others might take AA bateries or 9V cells to provide the power. Usually when I find a 5V power source, the first thing I do is hack off the power plug and modify it to become a USB socket. Why? Because I can find USB charge cables for most of the devices I own so why settle for something that only charges one device?

Also, you're now able to get big battery SLABS (like the one above) which have enough juice in them to charge a notebook instead of just a handphone. Just be ready to explain to airport security that the little square things they see in the baggage XRay aren't C4 charges. Hasn't happen to me.... YET! This particular beast is able to power my notebook for... come to think of it I really don't know the extremes yet, but it hits 50% after about 4 hours of usage. Oh... unfortunately big batteries like this are HEAVY!! So you have to determine wheter the extra battery life is worth the backache.

DC Inverter

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The picture above is what is known as a DC inverter, it changes DC current to AC current. In plain english, with an inverter you're able to have more or less a normal wall socket wherever you can find sufficient DC current for input. Usually they make inverters that run off 12V or 24v DC. Where can you find 12V or 24V? Your car cigrette ligther plug is usually 12V DC. That means with an inverter you can basically run anything in your car.... As long as the inverter can output enough current to power the thing that is. Inverters are sold based on their peak output current, say.. 150W, 240W or 300W. To see how many Watts you need to power a plug, well... I'm not an eletrician but the easiest way is to take the Volts of your power adapter and multiply it with the Amps it outputs. A Typical phone charger usually provides 5V,1A of power so it needs 5V x 1A = 6W of power. A notebook charger might provide 15V,4A of power so it needs 15V x 4A = 60W of power.

Once you know how much current you need you can buy an inverter that suits your capacity, but never buy EXACTLY what you need. So you've done the calculations and you see that you'll need 140W of current, do not buy a 150W inverter. Always buy something that gives you more breathing space. This is because usually the output current listed on the inverter is it's PEAK output current, which it usually cannot sustain for extended periods.

Inverters used to be hard to find around here, but recently within the last 2 years they seem to be popping around all like a common item. Nowadays you can easily find a 150W inverter in Low Yat.

There ARE some precautions to inverters though, different units have different build qualities and power output circuits. Some might have better air circulation or are just less prone to over heating, some might tolerate low power supply better. So no two inverters might be the same and I'm not really qualified to say what's a better inverter. I do know that having an inverter in your car is a god send for road warriors cause you can keep that laptop well juiced while on the road. :P

Perpetual Power Source

The two power sources mentioned above will already help extend the use of eletrical gadgets for someone on the go, but... the portable battery pack is FINITE, once you exhaust it you'll either have to recharge it or replace the batteries in it if you're using one that takes batteries. And the inverter needs a car for it to work in most scenarios. If you were stranded on the roof of your house or in a evacuvation center you'll need something that gives you a replenisable power source that you can use over an extended period of time.

When you think about replenishable power sources you probably would have thought of solar power. And that's a good idea too..

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This is a SolarMio solar panel which I acquired recently, it's actually a solar battery which means it has an internal battery as well so basically when it's out in the sun it charges the internal battery and then you can use it like an external battery pack. The problem with the unit is... I have yet been able to fully charge the thing in the sun, I've tried putting it on my dashboard.. hanging it on my balcony on a sunny day.. nothing seems to work, the battery DOES indicate that it's charging so I think it probably takes a LOOOOOOONG time to recharge fully. There are also other Solar Panel power supplies out there which do NOT have an internal battery with these such Solar Panels, if you want juice you must have THE SUN!!!!

The other sort of replensihable power sources which I do have experience with is the kinetic power supply, in this case.. my hand cranked 5V power supply.

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This used to be a 5V Nintendo Gameboy Advance SP charger, and it worked simple enough. Just plug it into your GBA start cranking and your device will be charged. Like I mentioned before, first thing I did after getting it was to hack off the connector given and put a USB socket on it so I can use it on my other devices. The main disadvantage about this type of power source is that you have to keep going and going and going... and the moment you stop, so does the power! It's shape also isn't designed too well to be used for a long time, it'd just tire you out after oh... a minute or so of cranking?

I've find a way to work around this disadvantage, instead of using the crank supply to charge a device directly. I use it to charge my external battery pack instead, this will leave my hands free to fiddle with the gadget when I need the juice. But truth be told.. as safe I feel with this thing in my gear bag knowing that I will always be able to recharge my phone.. I really wish I never have to fallback to this.


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