New Owner Questions - XC60

[apersson850]

Originally Posted by Wizzpop

Just to be clear a kW is the voltage applied multiplied by the amps, so with a mains voltage of 240 V and a current of 13 A you are supplying 240x13 W i.e. 3kW.

Sorry to be nitpicking but that's not true either in this case. Not even after me fixing a prefix error in a unit in your sentence.

What you feed your car with is alternating current. So the effective power (watt, W) supplied to the car is the voltage multipled by the current multiplied by the power factor. For a resistive load the power factor is 1, but that's rarely the case where rectifiers are involved.
In such cases the apparent power (volt-amps, VA) is indeed the voltage multiplied by the current, but the effective power actually producing the direct current that charges the battery is lower, since the power factor is the cosine of the phase angle between voltage and current and the absolute value of a cosine of a real argument can never be larger than one.

[Discoman]

Re the air suspension I always use the easy entry/exit. Five years in all ok so far, fingers crossed.

For me this was part of the reason for choosing it but I get your point. I mainly drive mine in Dynamic which lowers the car so it is changing the height anyway. I would a bit worried about not varying the height at all as the system might seize up in someway.

[apersson850]

It doesn't seize. It changes the suspension all the time to accomodate different load conditions and to compensate from temperature induced changes.

On the XC90 2019 I recently bought the compressor had failed. It was recently replaced by the previous owner.

[Wizzpop]

Originally Posted by apersson850

Sorry to be nitpicking but that's not true either in this case. Not even after me fixing a prefix error in a unit in your sentence.

What you feed your car with is alternating current. So the effective power (watt, W) supplied to the car is the voltage multipled by the current multiplied by the power factor. For a resistive load the power factor is 1, but that's rarely the case where rectifiers are involved.
In such cases the apparent power (volt-amps, VA) is indeed the voltage multiplied by the current, but the effective power actually producing the direct current that charges the battery is lower, since the power factor is the cosine of the phase angle between voltage and current and the absolute value of a cosine of a real argument can never be larger than one.

Although you are correct all I was trying to explain to a non Chartered Electrical Engineer the basics of the units. I did point out that there are losses (power factor, etc) involved which would increase charge time and thanks for correcting my typo.

[apersson850]

I kind of understood your ambition. But it usually helps to be very correct when you explain to the less educated, since any detail you get wrong may confuse them further. A professional on the other hand will just notice the error and fill in the correct information automatically, since he'll already know what you mean. That's like when I read it, with my history as a professional in the electric business since 45 years now.

Soon I'll retire and will have more time to spend on web sites like this one!

[sk546]

Originally Posted by apersson850

Soon I'll retire and will have more time to spend on web sites like this one!

Oh dear, that'll be a sad day for everyone.

[apersson850]

Thank you for the encouragement.