The EV fact thread

[clk320x]

Interestingly, my car showed the exact same battery charge percentage after 4 weeks, suggesting that the loss was minimal (within the 1%). But, ultimately, all these figures come from the car's computer, so who knows if they are actually accurate....

that’s excellent

 

[clk320x]

The IONIQ 5 (and I believe also Teslas) only charges the 12v battery when the 'ignition' is on (or, rather, when the car is powered up).

The Tesla will wake up and top up the 12V if it gets low whilst parked. The voltage is constantly monitored. The car will display a message when the it’s time to replace the 12V as it notices it’s having to wake up more regularly to keep it topped up.

 

[clk320x]

Why can't the LI main battery top up the 12v battery (until it has say 10% life left) ?

It does on Tesla’s until the HV is depleted, no idea about other brands.

 

[markjay]

The Tesla will wake up and top up the 12V if it gets low whilst parked. The voltage is constantly monitored. The car will display a message when the it’s time to replace the 12V as it notices it’s having to wake up more regularly to keep it topped up.

There was also a separate question if the 12v battery gets topped-up while the car is connected to a charger - I don't know the answer regarding the IONIQ 5, because I've never left my car connected to the charger for longer than needed - I guess that this is a scenario that applies to people who have a driveway and a private charger.

 

[clk320x]

There was also a separate question if the 12v battery gets topped-up while the car is connected to a charger - I don't know the answer regarding the IONIQ 5, because I've never left my car connected to the charger for longer than needed - I guess that this is a scenario that applies to people who have a driveway and a private charger.

Yes, when left on a conventional charger then the HV will top up once it discharges a few % to keep it at the preset limit, the car looks after the other systems as necessary including the 12V.

 

[markjay]

Yes, when left on a conventional charger then the HV will top up once it discharges a few % to keep it at the preset limit, the car looks after the other systems as necessary including the 12V.

It seems that some EVs manage the charging of the 12v battery better than others....

 

[Dryce]

There was also a separate question if the 12v battery gets topped-up while the car is connected to a charger -

Logically it has to be a priority if it is critical to the car's security systems.

 

[markjay]

Logically it has to be a priority if it is critical to the car's security systems.

The 12v battery gets charged while the car is being driven (or, rather, 'switched on').

If the 12v battery isn't fully charged, it's not a major issue, but the charger can't 'know' that the car will not be driven for a while. The 12v battery level may not be critical or very low at that point, just not fully charged.

So I don't agree with the logic that it is a priority to always keep the 12v battery fully charged - because it's only a problem if it gets depleted.

BTW, on a couple of occasions I tried to update the maps on the satnav from a USB drive (I don't have the patience to wait for the 4g download...) after the car was stood for a while, I got a message that said that the 12v battery wasn't sufficiently charged and that I should drive the car to charge the battery before reattempting the maps update.

 

[markjay]

Regarding range.... my car's WLTP range is 285 miles.

Prior to my trip to Switzerland, the car was used predominantly for short journeys in town, and the predicted range with 100% battery was 340 miles (in summer).

After coming back from Switzerland, and having driven mostly at speeds of 110 to 120 kmh on Frenchon Swiss motorways, the predicted range at 100% battery is now showing as 220 miles (again, during summer).

This is why WLTP is useless (other than when comparing different car models) - because it won't tell you what sort of range you might actually get based on your particular driving profile.

 

[Dryce]

This is why WLTP is useless (other than when comparing different car models) - because it won't tell you what sort of range you might actually get based on your particular driving profile.

Well no better than the old urban/extra urban/combined numbers. We kind of learned to live with them as some sort of vague indicator.

I've been trying to figure the practicality of an EV or a PHEV over various journey profiles. Part of the problem is that the specific model variant and trim can make a difference. I'm also wondering with PHEVs if you lose out disproportionately in the EV mode compared with the official numbers if you drive about with a full fuel tank as deadweight.

(In principle if regenerative braking implementation / management is very good then that should even out driving profiles to some extent.)

 

[BTB 500]

Well no better than the old urban/extra urban/combined numbers. We kind of learned to live with them as some sort of vague indicator.

I've been trying to figure the practicality of an EV or a PHEV over various journey profiles.

The thing about range is that it matters most on a long run, where ICE vehicles perform much better than normal but EVs do the opposite. For shorter local trips range is immaterial as you won't be using it all anyway.

As discussed previously if you (a) very rarely do long runs or (b) want to stop every hour or two anyway then it's no big deal. If you like to press on (perhaps with two people sharing the driving) then it may be an issue.

I'm also wondering with PHEVs if you lose out disproportionately in the EV mode compared with the official numbers if you drive about with a full fuel tank as deadweight.

It will undoubtedly have some impact but it's a very small percentage of the total vehicle weight (60 litres of petrol is only 45 kg). I suspect range in EV mode will be much more affected by things like the ambient temperature.

(In principle if regenerative braking implementation / management is very good then that should even out driving profiles to some extent.)

AFAIK regen. braking is typically around 60-70% efficient so you'll never get back the additional energy you've consumed in accelerating extra mass (or raising it up hills).

 

[markjay]

As discussed previously if you (a) very rarely do long runs or (b) want to stop every hour or two anyway then it's no big deal...

....IF you're on a route that has fast chargers!

Again, it worked a charm in France and Switzerland, but I haven't tried it yet here in the UK.

In fact, in the 3 years that I've had the car, I've never charged it away from home (OK, I lie, I charged it once at the local Aldi for free).

 

[MikeInWimbledon]

Regarding range.... my car's WLTP range is 285 miles.

Prior to my trip to Switzerland, the car was used predominantly for short journeys in town, and the predicted range with 100% battery was 340 miles (in summer).

After coming back from Switzerland, and having driven mostly at speeds of 110 to 120 kmh on Frenchon Swiss motorways, the predicted range at 100% battery is now showing as 220 miles (again, during summer).

This is why WLTP is useless (other than when comparing different car models) - because it won't tell you what sort of range you might actually get based on your particular driving profile.

Surely your experience just shows that range varies according to driving style?

Your car’s current “estimate” will be equally wrong as you return to urban life, leaving those 130kph miles behind you.

The value of WLTP is as a standard for comparison vehicles. Change the driver, the journeys the speeds, and the season and actual will vary.

Does it matter much to the average driver doing mileages of less than 8,000 a year? Not a lot.

 

[markjay]

Surely your experience just shows that range varies according to driving style?

https://www.getyarn.io/yarn-clip/ac085a5f-945c-432c-9a09-6a08f0e23c72

Your car’s current “estimate” will be equally wrong as you return to urban life, leaving those 130kph miles behind you.

It's an estimate indeed, which is why I said 'predicted' range. Range can never be accurate, on any car, EV or ICE, because unlike m/kWh or mpg, it's not a measurement of past events (which, like every other measurement, will have a degree of accuracy), instead it's a projection and as such will be reliant on a number of assumptions made regarding future driving conditions.

The value of WLTP is as a standard for comparison vehicles. Change the driver, the journeys the speeds, and the season and actual will vary.

That's one of the points I was trying to make in my post.

Does it matter much to the average driver doing mileages of less than 8,000 a year? Not a lot.

Indeed, and that's a point I made in previous posts, I.e. that the 'range wars' are counterproductive, and if you don't make long journeys very often then you'll be better off with an EV equipped with a smaller battery - significantly less weight to carry around for no reason, and better use of the raw materials used to make batteries as the same amount of these substances will support a larger number of EVs.

 

[MikeInWimbledon]

Indeed, and that's a point I made in previous posts, I.e. that the 'range wars' are counterproductive, and if you don't make long journeys very often then you'll be better off with an EV equipped with a smaller battery - significantly less weight to carry around for no reason, and better use of the raw materials used to make batteries as the same amount of these substances will support a larger number of EVs.

Especially now that any damn fool can find an available charger quickly and accurately with apps like ABRP.

On that dozen or so occasions a year when you need a charger away from home. That Summer holiday etc.

Because the rest of the time you're just charging from home, or from that free charger at work, or the cheap charger near home, at the Supermarket, or whatever.

 

[MikeInWimbledon]

Thank heavens that EV's will be no longer exempt from London's congestion charges from January 2026

At last we can make some real progress on reducing congestion in London, and force workers back on to the bicycles, buses, and trains where they belong.

End to zero-emission discount in London’s congestion zones

 

[markjay]

At last we can make some real progress on reducing congestion in London, and force workers back on to the bicycles, buses, and trains where they belong.

You got me worried there for a minute, I thought I was getting early onset dementia, because I couldn't remember writing this post. I then realised it wasn't me who posted this - phew.

 

[ALFAitalia]

Thank heavens that EV's will be no longer exempt from London's congestion charges from January 2026



End to zero-emission discount in London’s congestion zones

Which of course will make no difference to traffic levels at all.....just like nothing else ever did for more than a year or so.

 

[SmartAmg]

Thank heavens that EV's will be no longer exempt from London's congestion charges from January 2026

Stab in the dark, here. You don't own an EV?

 

[MikeInWimbledon]

Stab in the dark, here. You don't own an EV?

Still trying to find one that I'd want to own drive.

Tesla S: too wide & big, not luxurious enough; Tesla 3Y: "They cannot be serious;" SUV's: who wants an SUV? I3: OK for London, but what about the long-haul ?

Bottom line: just being cheeky about greenwashed council taxes.