Do you put the heater on in the car?

forgotmyname

Except strider is wrong on that one, Anything electrical will cause the car to use more fuel, Tiny amounts
probably but more.

I ran an alternator off a drill once, It was fine until you applied a load, I tried a 5w interior bulb the drill could be
heard to slow. Using a 55w headlamp bulb and the drill stalled out. Not enough power/torque to keep the
alternator spinning with that load. Probably a 350w 240v cheapy electric drill.

Loads at higher speeds wont really make much difference, But at tickover the revs will need to be raised or
extra fuel added to keep the power/torwue high enough to compensate for the load.

Strider590

forgotmyname wrote: »

Except strider is wrong on that one, Anything electrical will cause the car to use more fuel, Tiny amounts
probably but more.

I ran an alternator off a drill once, It was fine until you applied a load, I tried a 5w interior bulb the drill could be
heard to slow. Using a 55w headlamp bulb and the drill stalled out. Not enough power/torque to keep the
alternator spinning with that load. Probably a 350w 240v cheapy electric drill.

Loads at higher speeds wont really make much difference, But at tickover the revs will need to be raised or
extra fuel added to keep the power/torwue high enough to compensate for the load.

The alternator does not place any addition mechanical load on the engine, no matter how much electrical power you use.
To suggest that the alternator somehow applies an additional mechanical force when you use more power, is totally illogical

The alternator over produces electricity, this electricity is used to recharge charge the battery, but once that is fully charged the electricity being produced simply goes to waste.

On the same principle that power stations want to balance the load throughout the day as a power station burns just as much fuel at night as it does during the day, but at night there's a HUGE wastage.... Hence schemes such as economy 7 (Or whatever it is now).

adouglasmhor

Strider you are mistaken, anything drawing a heavy load will put more strain on the alternator and engine.

I am Scottish so just imagine me saying "ye canny change the laws of physics captain". It has an authority to it

esmerobbo

An alternator putting out 55Amps will use 1 hp.

1 HP = 746 watts most alternators produce 13.8 volts so 746watts divided by 13.8 = 54 amps.

Gloomendoom

Strider590 wrote: »

The alternator does not place any addition mechanical load on the engine, no matter how much electrical power you use.
To suggest that the alternator somehow applies an additional mechanical force when you use more power, is totally illogical

Perhaps to you. Energy can be neither created nor destroyed, although it can be transformed from one state to another. It's a basic law of physics.

In this case energy released by the combustion of fuel is being transformed into mechanical energy which is then transformed into electrical energy to power the light.

The alternator over produces electricity, this electricity is used to recharge charge the battery, but once that is fully charged the electricity being produced simply goes to waste.

It can't go to waste, it has to be transformed into something else. When the battery is full or the lights are turned off, less electricity is needed so the alternator becomes easier to turn, less mechanical load is put on the engine and that equates to less fuel burnt.

thescouselander

Strider590 wrote: »

The alternator does not place any addition mechanical load on the engine, no matter how much electrical power you use.
To suggest that the alternator somehow applies an additional mechanical force when you use more power, is totally illogical

The alternator over produces electricity, this electricity is used to recharge charge the battery, but once that is fully charged the electricity being produced simply goes to waste.

On the same principle that power stations want to balance the load throughout the day as a power station burns just as much fuel at night as it does during the day, but at night there's a HUGE wastage.... Hence schemes such as economy 7 (Or whatever it is now).

No no no, thats not right - no electricity can go to waste. The alternator will sustain the running of the car while it is turning. Also, because the alternator is running at a higher voltage than the battery it will take most of the load. The battery is just there for starting the engine or running devices on the car while the engine is stopped.


You can see the alternator takes the electrical load if you let the car idle and then turn on a high load device like the rear de mister - you will see the revs drop briefly as more load is put on the alternator and the engine ECU compensates to get the revs back up.

wearside_2

Strider590 wrote: »

You mean she doesn't whack it all the way up to 60 so that it warms up faster?

:rotfl::rotfl:Nope, she is at that age where she is hot all of the time:)

Before you say anything....NO!!:eek::o

Strider590

The alternator does not directly place an addition mechanical load on the engine dependant on power usage.... It just DOESNT.

And electricity can go to waste because it's voltage and therefore a potential energy. Just like in your homes, where does the 230v AC "go" when you turn your TV off?

Current is what drives electrical devices and voltage x current = power. Draw too much current and the voltage starts to drop because a device can only supply a limited amount of power, typically for a car alternator this is around 70Amps, around 840 watts at 12v DC......
The reason the alternator can do this, is because it generates an AC voltage which is then converted down to 12vDC (actually closer to 14 but hey), this means it can potentially supply a great deal more current than a typical 12v supply could on it's own.
So if you try to pull say 1KW at 12v DC you'd probably blow something up.

Another example - We all have mobile phone chargers..... They use mains power whether you connect your phone to it or not. When not connected, the 5v/7.5v sits there doing nothing and disappears when you flip the switch on the mains socket.... Where does it go?

adouglasmhor

Electrical power is Potential difference (V)(volts) times Current (I)(amps).

V=I/R (R is resistance Ohms Ω)
It just doesn't is bollox strider. Just listen to an engine change tone when your fans kick in. Where do you get this from? Electricty is just volts - one out of three variables, poor.

Lum

Strider590 wrote: »

Another example - We all have mobile phone chargers..... They use mains power whether you connect your phone to it or not. When not connected, the 5v/7.5v sits there doing nothing and disappears when you flip the switch on the mains socket.... Where does it go?

Heat and noise