free battery recharging

Ebe_Scrooge

esuhl wrote: »

Maybe we could modify the alternator so that it placed the maximum possible load on the engine during braking, but no load during acceleration...

Slightly different technology, but a similar idea .... regenerative braking. Google it

chrisw

Mine's called Intelligent Alternator Control so the alternator is only engaged during overrun or when the brakes are applied, provided there is sufficient charge in the battery.

http://www.bmw.co.uk/bmwuk/efficient_dynamics/homepage/0,,1156___,00.html?section=brake_energy_regeneration

spud17

If it were true that no extra fuel was used, because the driver doesn't notice any difference in engine performance, then I claim free electricity from my supplier.
Put simply, when I turn on my cooker and the power station doesn't drop down a gear and belch (even) more smoke it can't be costing anything.

Kernel_Sanders

esuhl wrote: »

Oh, never mind. Here's a much easier way to save money:
http://www.dealextreme.com/p/neo-socket-fuel-economizer-for-car-save-fuel-gas-10-30-12v-52013

Funny, isn't it... If it only costs US$4.40, it makes you wonder why such cutting edge environmental technology comes out of a cheap Chinese factory instead of being installed in cars as standard by the manufacturers.

The only positive review for that gadget states "In my personal humble opinion, just buy it, there is nothing for you to lose." Err... yes there is!

sabretoothtigger

I like your thinking there, too! We could make some kind of cigar-socket recharging device that activates only when the brake pedal is depressed.

The electric car hybrid things do this. If you spend twice as much on your car you will get fancy gadgets to harvest energy from braking. Trains also do this


I also thought the load from an alternator was constant. Are we saying the resistance on the engine is variable, because I thought it just recharged the battery circuit.
The RPM of the engine increases the amount of electricity produced by the alternator. Hence if you were to drive around 2000 rpm or less with full electric on you might find you run the battery flat.

It doesnt appear to adapt, I believe the alternator produces too much energy in most cases but you will find in city traffic jams in winter people will run out of electricity. All they have to do is rev the engine alot but not many will do this in a traffic jam or have battery meters, etc

LucianH

esuhl wrote: »

Oh, never mind. Here's a much easier way to save money:
http://www.dealextreme.com/p/neo-socket-fuel-economizer-for-car-save-fuel-gas-10-30-12v-52013

If you think that's good, take a look at this:

http://www.ecomagnets.com/motoflow.htm

They had fun with the buzz-word generator but some how missed the "a" out of "Central Reverse Polarity". I also like one of the FAQs:

"Will I notice the benefits immediately? In most cases no, a period of 'saturation' has to occur..."

The sad thing is, they're charging 40 quid for a few magnets.

johnmc

If the OP really wanted "free" charging then he should invest in solar chargers http://www.maplin.co.uk/solar-powered-12v-1.5w-battery-trickle-charger-98358.

Of course, that would mean paying out some money, so it's not really free, just cheap. BUSTED!

Or he could make a Stirling engine and connect that to a seperate alternator to harness the wasted heat energy from the engine
http://www.youtube.com/watch?v=yK_V50aHs1M

Oh, wait a minute, that would be extra weight to carry, which would take extra fuel to carry. BUSTED!

There's no such thing as free energy. Only getting someone else to pay for it.

spannerzone

LucianH wrote: »

If you think that's good, take a look at this:

http://www.ecomagnets.com/motoflow.htm

They had fun with the buzz-word generator but some how missed the "a" out of "Central Reverse Polarity". I also like one of the FAQs:

"Will I notice the benefits immediately? In most cases no, a period of 'saturation' has to occur..."

The sad thing is, they're charging 40 quid for a few magnets.

Blimey they were flogging these in the 1990's and if you read the tests it states the test was carried out on a Vauxhall Cavalier with 106000 miles on the clock! - I remember some journalist 20 years ago saying these magnets were a scam and the 'evidence' was based on a clapped out Vauxhall, and here they are still flogging the same crap with the same flawed evidence!

I expect they still sell those metalic balls in a net that you put in the fuel tank to enhance the fuel burn (remember those?)

:rotfl:

spud17

sabretoothtigger wrote: »

I also thought the load from an alternator was constant. Are we saying the resistance on the engine is variable, because I thought it just recharged the battery circuit.
The RPM of the engine increases the amount of electricity produced by the alternator. Hence if you were to drive around 2000 rpm or less with full electric on you might find you run the battery flat.

It doesnt appear to adapt, I believe the alternator produces too much energy in most cases but you will find in city traffic jams in winter people will run out of electricity. All they have to do is rev the engine alot but not many will do this in a traffic jam or have battery meters, etc

The following are broad generalisations.

Load on the alternator varies all the time.

Let your engine idle and turn on the lights, then heater ,then heated rear window, and notice how your revs drop as the load increases.

BUT note, many newer cars have engine management systems which will subtly increase the fuelling to maintain the idle revs.

Alternators run at around 2x engine revs, they produce max voltage (14v) at 1000 alternator revs, i.e 500 engine rpm. As engines idle at around 800rpm there should be enough overhead to avoid running the battery flat.
The above assumes the charging system is in decent nick and you don't have every possible electrical device turned on while sitting for very long periods at idle.

Even my old 1988 Peugeot had an 80amp alternator, so the chances of running out of 'electric' even at idle should be pretty remote.


edit:
Just to add, if you do use jump leads to start a car, then there is no need to rev the t**ts off it to charge the 'flat' battery, in fact you could end up causing even more problems by destroying the alternator. Some even suggest turning on the lights before 'jumping' the battery, this avoids the surge destroying the diode pack.

sabretoothtigger

Needs a mechanic to settle this but I dont think you increase the fuel cost from using the cigarette lighter so long as you were driving fast anyway. Cars are not this efficent, most of the fuel is wasted producing heat and most of the alternator energy is not used up or contained perfectly in the battery circuit it is just wasted every journey providing resistance to the engine and no actual benefit.

Only a hybrid is going to constantly take all electric power and use it every journey, so by removing any you increase fuel cost.

Electric cars would mostly be cheaper to run because you can recharge them from domestic supply and avoid the fuel duty. only 5% tax instead of 95% or whatever silly amount we pay now. On a flat long road I dont think they are any more efficient but low speed yes a milk crate wins the day with high torque


3p a hour might right but cars throw fivers out the window while being driven, even a BMW has not drastically increased this fatal inefficiency.
And the hybrids really aint so fab without subsidy, the batterys are so heavy they lose alot of the efficiency there. But I do agree they should be free in London for example