I have a friend who always charges his phone in the car on the reasoning that its free electricity instead of doing it at home with the (slight) cost involved. I say he is a cheapskate and that it actually increases his fuel consumption and he sisnt saving anything.

What do you lot think?

I think you should do it at work and save even more than him.

I’d say that you both need to get out more, or possibly less.

And he is right ( but only if the car is stationary and is not on a conveyor belt ).

He sounds like my wife’s barmy uncle who once ruined an entire Christmas Dinner by drunkenly banging on about how if we fitted small generators to our taps we could power our houses by water pressure for free.

The principle of conservation of energy states that energy cannot be created or destroyed, although it can be changed from one form to another.

He has also removed the light bulb from his fridge to keep the bills down.

Electricity in cars is ere, everyone knows that.

The most profitable power companies use giant car parks full of cars instead of power stations.

Seriously…neither is free, I’d expect the car to be more expensive, try Googling it.

he’s a cheapskate

He should have charged his phone in the pub

I would think he was right, the cars alternator is always connected whether the battery needs charging or not, it only makes sense for an alternator to be rated for a higher current than you would normally be expected to pull with all electric gizmos on. As long as he’s not leaving the engine on purely to charge it – He is just making more efficient use of the excess headroom in the alternator?

Would be happy to be told differently though.
He is still a cheap skate:)

He’s wrong.

He is wrong

The greater electrical load you put on the alternator the greater the mechanical load it will put on the engine and thus your fuel tank.

In a Prius however if he plugged it in while braking, maybe 🙂

Actually there is another way…. The two of you could have charged the phone from all the hot air you produce in the pub 🙂

Yeah, makes sense actually. I was wrong

He sounds like my wife’s barmy uncle who once ruined an entire Christmas Dinner by drunkenly banging on about how if we fitted small generators to our taps we could power our houses by water pressure for free.

Charging from the car costs extra petrol. Charging at home cost extra electricity.

Both are so small you’ve wasted more energy typing in your question.

Just charge the phone while you’re in the pub.

Now if he fitted a dynamo to his bike and charged his phone from that .

Now if he fitted a dynamo to his bike and charged his phone from that .

Sure i’ve seen that somewhere. Hazy memory but I think there might be a Nokia one.

Decided to check just in case I’d dreamt it.

Nokia bike charging kit

charge your phone at work

if we fitted small generators to our taps we could power our houses by water pressure for free

You could get some energy this way, but hardly any unless you ran the taps all day on full which would be silly. Energy must be conserved of course, so what’d happen is that the water would come out of your taps more slowly.

I thought car engines gave off loads of heat, which has to be cooled. When I had a very old car and lived in a warmer country you had to turn the heaters on full noise when stuck in traffic to stop the radiator boling.

Surely this heat could be harnessed for something ??

I thought car engines gave off loads of heat, which has to be cooled.

Indeed, and car campanies are looking at ways to extract this ‘waste’ heat and convert it into something useful (apart from keeping you warm).

Edit to add link:
url=http://inhabitat.com/new-car-engine-generates-electricity-from-exhaust-heat/]using waste heat[/url]

Surely this heat could be harnessed for something ??

Quite right. There are a few ideas.

One of my faves is a guy who invented the 6-stroke engine. First four are the same as normal, then the 5th is squirting water into the chamber which turns into steam and gives another power stroke. The engine needs no other cooling and runs slightly warm to the touch.

A nice advantage of hybrids is that you can generate extra leccy from all sorts of other systems and feed it back into the system.

My ideas:

Connect a generator to an exhaust turbine, much like a turbocharger.
Use resistive damping on the suspension to generate current
Use a turbine to generate power from the super heated pressurised water in the cooling system instead of a radiator.

Runs off to patent and car-engine-heat-driven-phone-charging-stirling-engine

although you could power one with the heat from your hand

[video]http://www.youtube.com/watch?v=QJd2flOjOy0&feature=related[/video]

although they work on temperature difference, so you can power them with an ice cube too

[video]http://www.youtube.com/watch?v=-szQ-EvmHEg[/video]