Is it worth getting an EV?

thegentleway

fred990 said:

thegentleway said:

macman said:

EV batteries reduce in capacity, but not in efficiency. The range reduces, but the cost per mile does not increase.
The ICE equivalent would be the petrol tank magically shrinking-you'd still get the same mpg.

Batteries do reduce in efficiency. One of the main ageing mechanism is the solid electrolyte interphase layer growth, which increases the internal resistance, and therefore reduces the efficiency.

Indeed....laughable that EVangelists believe in loss of capacity but not efficiency! Not a direct swipe at macman btw.

So....how do you measure IR in a car pack? 

If I can't check a used ev battery pack IR it's non starter. 

measure the voltage drop and divide by the load current: R = V/I

fred990

thegentleway said:

fred990 said:

thegentleway said:

macman said:

EV batteries reduce in capacity, but not in efficiency. The range reduces, but the cost per mile does not increase.
The ICE equivalent would be the petrol tank magically shrinking-you'd still get the same mpg.

Batteries do reduce in efficiency. One of the main ageing mechanism is the solid electrolyte interphase layer growth, which increases the internal resistance, and therefore reduces the efficiency.

Indeed....laughable that EVangelists believe in loss of capacity but not efficiency! Not a direct swipe at macman btw.

So....how do you measure IR in a car pack? 

If I can't check a used ev battery pack IR it's non starter. 

measure the voltage drop and divide by the load current: R = V/I

Yes quite.....I can do that at home with my mountain of lithium batteries (of various chemistries) and sophisticated chargers etc but what if I go look at a car? 

How/when would you check the voltage drop? WOT? Do the dealers have a load tester? 

fred990

Cool....Tesla apparently just announced up to 20% price cuts.

Kia/Skoda money....could get interesting. 

thegentleway

fred990 said:

thegentleway said:

fred990 said:

thegentleway said:

macman said:

EV batteries reduce in capacity, but not in efficiency. The range reduces, but the cost per mile does not increase.
The ICE equivalent would be the petrol tank magically shrinking-you'd still get the same mpg.

Batteries do reduce in efficiency. One of the main ageing mechanism is the solid electrolyte interphase layer growth, which increases the internal resistance, and therefore reduces the efficiency.

Indeed....laughable that EVangelists believe in loss of capacity but not efficiency! Not a direct swipe at macman btw.

So....how do you measure IR in a car pack? 

If I can't check a used ev battery pack IR it's non starter. 

measure the voltage drop and divide by the load current: R = V/I

Yes quite.....I can do that at home with my mountain of lithium batteries (of various chemistries) and sophisticated chargers etc but what if I go look at a car? 

How/when would you check the voltage drop? WOT? Do the dealers have a load tester? 

I don’t think you would be able to measure the efficiency via the internal resistance in a car. You also don’t need to as they are so efficient to start with ~95% so even if your internal resistance doubles then you’d still be at ~90% efficiency. By then the range will be 70-80% so presumably efficiency won’t be your main concern.

fred990

thegentleway said:

fred990 said:

thegentleway said:

fred990 said:

thegentleway said:

macman said:

EV batteries reduce in capacity, but not in efficiency. The range reduces, but the cost per mile does not increase.
The ICE equivalent would be the petrol tank magically shrinking-you'd still get the same mpg.

Batteries do reduce in efficiency. One of the main ageing mechanism is the solid electrolyte interphase layer growth, which increases the internal resistance, and therefore reduces the efficiency.

Indeed....laughable that EVangelists believe in loss of capacity but not efficiency! Not a direct swipe at macman btw.

So....how do you measure IR in a car pack? 

If I can't check a used ev battery pack IR it's non starter. 

measure the voltage drop and divide by the load current: R = V/I

Yes quite.....I can do that at home with my mountain of lithium batteries (of various chemistries) and sophisticated chargers etc but what if I go look at a car? 

How/when would you check the voltage drop? WOT? Do the dealers have a load tester? 

I don’t think you would be able to measure the efficiency via the internal resistance in a car. You also don’t need to as they are so efficient to start with ~95% so even if your internal resistance doubles then you’d still be at ~90% efficiency. By then the range will be 70-80% so presumably efficiency won’t be your main concern.

Yes valid point, esp the effect on range (anxiety!).

Just trying to relate to years of messing with 6/8/10s lithium batteries, often in series, and their degradation when just one cell (for example) goes bad.

The homework phase for going EV!  ...probably second hand. 

marlot

fred990 said:

Cool....Tesla apparently just announced up to 20% price cuts.

Kia/Skoda money....could get interesting. 

Yep.  I'm thinking of cancelling my toyota hybrid order and going for a model y.

fred990

marlot said:

fred990 said:

Cool....Tesla apparently just announced up to 20% price cuts.

Kia/Skoda money....could get interesting. 

Yep.  I'm thinking of cancelling my toyota hybrid order and going for a model y.

Indeed...could be tempted by an S.
Will read up on the charging deal today 🤔. 

thegentleway

fred990 said:

thegentleway said:

fred990 said:

thegentleway said:

fred990 said:

thegentleway said:

macman said:

EV batteries reduce in capacity, but not in efficiency. The range reduces, but the cost per mile does not increase.
The ICE equivalent would be the petrol tank magically shrinking-you'd still get the same mpg.

Batteries do reduce in efficiency. One of the main ageing mechanism is the solid electrolyte interphase layer growth, which increases the internal resistance, and therefore reduces the efficiency.

Indeed....laughable that EVangelists believe in loss of capacity but not efficiency! Not a direct swipe at macman btw.

So....how do you measure IR in a car pack? 

If I can't check a used ev battery pack IR it's non starter. 

measure the voltage drop and divide by the load current: R = V/I

Yes quite.....I can do that at home with my mountain of lithium batteries (of various chemistries) and sophisticated chargers etc but what if I go look at a car? 

How/when would you check the voltage drop? WOT? Do the dealers have a load tester? 

I don’t think you would be able to measure the efficiency via the internal resistance in a car. You also don’t need to as they are so efficient to start with ~95% so even if your internal resistance doubles then you’d still be at ~90% efficiency. By then the range will be 70-80% so presumably efficiency won’t be your main concern.

Yes valid point, esp the effect on range (anxiety!).

Just trying to relate to years of messing with 6/8/10s lithium batteries, often in series, and their degradation when just one cell (for example) goes bad.

The homework phase for going EV!  ...probably second hand. 

There’s usually some redundancy so a single bad cell doesn’t take out an entire string

Grumpy_chap

fred990 said:

Cool....Tesla apparently just announced up to 20% price cuts.

Kia/Skoda money....could get interesting. 

Except Kia / Skoda EV's have not been at Kia / Skoda money but some much higher number.

At some point, the genuinely affordable EV has to happen.
It was not long ago Elon said the target was an EV at £25k, then that got lost in time.  The idea seems to have resurfaced recently.  If that become reality and with a range comparable to the TM3LR, then it will be a real ground breaker.

EV versions of regular cars (e.g. Corsa) are simply not priced sensibly at present from the legacy automotive manufacturers.  Nor are the specific EV's (id3).

Some kind of price rationality has to come eventually.  Perhaps that will be sooner rather than later if we are entering the point at which EV affordability starts on the road of the technology development curve reaching some maturity.

I guess Tesla will need to bring some standardisation to their vehicles as the customer base evolves from early adopters to more regular profile of the population.  The chop and change of specification will be less tolerated as the customer base widens, for example I read somewhere recently that Tesla had removed rear parking sensors.  That type of feature will either need to be in or out but not at the whim of the manufacturer if the appeal of a lower cost car is to be maintained.

Herzlos

I'm not sure I'd touch a Tesla these days. Whilst I'm fairly sure people are managing Musk to prevent him doing too much damage, I don't trust him insisting in making changes that'll hinder me later in ownership like a software update that turns existing features into a subscription model.

At least the traditional manufacturers are run by committee and less likely to do something deeply unpopular.

I'm guessing the price reduction in Teslas is somehow related to the collapsing share priced as the world watches Musk screw up Twitter so badly.