Less PHEV EV range this winter than last winter ?

[Nick72]

13 hours ago, GBgraham said:

It is good for the system that the voltages are kept high as it extends battery life. If we knew the draw in amps or watts and then by to applying Ohms Law you would see the difference between 240v vs 355v, a guess of around 30% less power required. . . higher the voltage, lower the amperage.

V = I x R

P = I x V

H = I^2 x R

Noting the need to calculate RMS for AC.

[GBgraham]

10 hours ago, Nick72 said:

V = I x R

P = I x V

H = I^2 x R

Noting the need to calculate RMS for AC.

I was trying to keep it simple but you forgot to mention the coefficient calcs😜

[HSDish]

Now You went way ower my horizon 🙂

[NASY]

Keeping it on everyone's horizon, higher voltages mean lower losses and smaller conductors required to carry lower current. The power requirement doesn't change with variation in voltage - it is always what it is, shame really.

[Nick72]

6 hours ago, NASY said:

Keeping it on everyone's horizon, higher voltages mean lower losses and smaller conductors required to carry lower current. The power requirement doesn't change with variation in voltage - it is always what it is, shame really.

Exactly. Push V high to reduce I for a given or fixed power P since heating losses are H = I^2 * R so just halving I by doubling V will result in a quarter of the loss due to cable resistance. 

We can bring in the resistivity equation at this point to further improve our efficiency but I suspect everyone is now already bored 🤷😂

 

[philip42h]

29 minutes ago, Nick72 said:

Exactly. Push V high to reduce I for a given or fixed power P since heating losses are H = I^2 * R so just halving I by doubling V will result in a quarter of the loss due to cable resistance. 

We can bring in the resistivity equation at this point to further improve our efficiency but I suspect everyone is now already bored 🤷😂

Yes, since, unless the designer is an utter muppet, the power loss in the cable will be negligible in comparison to the power consumed in the connected 'appliance'. 😉

[NASY]

Philip makes a good point - only really high power systems or ones which occupy considerable real estate will need to be overly concerned with losses - unless of course you're talking audio. As for Muppets - they're the product of great designers rather than being designers.