How to - any help Electronics/electricians

brambram

Can it be done - wire a small energy saving light bulb table lamp to an aa battery. Done a quick internet search and found a bit on it. but its a bit vague. If it can be done is it safe to do all the lamps in the house, I am thinking low energy batteries 16 for a quid at pound store to save on leccy.

Owain_Moneysaver

Assuming pound store worst case zinc-carbon batteries with a capacity of 400 mAh, that's a total of 6400 mAh for £1.

6.4 Ah at 1.5 volts is 9.6 Wh, so your batteries are costing you about 10p per Watt-hour.

Electricity from the mains is about that per kiloWatt-hour so your AA batteries could be costiing you 1000 times as much as electricity from the mains, as well as being horribly environmentally unfriendly with the manufacture, packaging, transport and waste disposal.

Someone can correct me if I've calculated the Watt-hours incorrectly but I doubt I'll be out by 1000 times.

brambram

hi
thanks but is this safe



http://www.youtube.com/watch?v=X2wPLYTrc8E


there has gotta be a way.

paddyrg

As above, the cost involved in storing electricity (which is massively inefficient) is so high, you can only lose money on the deal. Batteries do not create electricity, only store it (badly), so someone, somewhere has to use EVEN MORE electricity to make it than you get from it, and even if by some miracle that was cheaper than your home leccy by a factor of 3 or 5 or 10 (it won't be, things do have a fundamental cost too), you still have all the energy wsted in transport, inefficiency, *safe disposal*, etc.

As for running a mini fluorescent tube for 24h from a dead AAA, forget it, don't believe everything youread on the internet. Yes, a flasher circuit steps up the voltage, but it does so by using electricity from the battery, 'dead' or otherwise. Did you see just how dim that bulb glowed? Not terribly impressive. That higher voltage will certainly tickle if you touch it - in fact you could use the circuit to make a better cattle prod than light ballast. And be aware those CFL tubes are pretty nasty in themselves - and in my opinion an environmental con anyway as the cost of manufacture and toxicity of the chemicals is much higher. I really could not recommend playing about with them like that in the dream of free electricity.

If for some reason you have access to lots of near-dead batteries you want to squeeze the last drips from (as opposed to buying new from cheapo shops), make a Joule Thief circuit which is pretty efficient at lighting an LED with the dog-ends of batteries, certainly the best bang for buck, and safest. http://www.emanator.demon.co.uk/bigclive/joule.htm - a very efficient little circuit, considering.

brambram

Ahh well thanks any ways

squeaky

Hi

I see that you have some answers, but in fact this thread would be best placed on our techy board - so I'm going to move it across there.

You may get more answers there; though I doubt that any well recommend this idea.

Forum_Team wrote:

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brambram

hi thanks
I posted then realised after that there were other boards to place it but i wasn't sure about how to move it and did not want to post on more than one board in case I annoyed every one.

paddyrg

brambram wrote: »

Ahh well thanks any ways

Mind you, if you're even slightly technical, it can be fun and cheap to make those Joule Thief circuits



Tiny and pretty simple! That link I gave has all the details you need

Owain_Moneysaver

paddyrg wrote: »

make a Joule Thief circuit which is pretty efficient at lighting an LED with the dog-ends of batteries, certainly the best bang for buck, and safest. http://www.emanator.demon.co.uk/bigclive/joule.htm - a very efficient little circuit, considering.

It's a novelty finding anything 'safe' by Big Clive.

Usually every time I point anyone to that site I have to do a big red safety warning! :rotfl: