Electric vehicles (seasonal rambling) Featured

My point is, no matter what kind of vehicle you shop for, it has to be capable of handling local (dangerous) driving situations that you know of.

I had to rule out some of the cars I took for test drives, because of that. They would not have been safe on merges.

You can take a fully-laden transport up our ramps, no problem at all. It's because drivers in the lane you are entering, see your vehicle type, and they all move over to make room. But for smaller vehicles that cannot clearly be seen or judged, there is some amount of extra risk.

I know, anecdotally, the drivers where you drive, drive with much smaller clearances. We usually use larger spacings.

To give an example of conditions on a roadway, imagine a divided highway with four lanes going in each direction. The posted limit is 80km/hr. The traffic is all moving at 120km/hr. All four lanes are plugged with traffic. The police speed traps ? Useless. They pull over the odd car, for their own entertainment. You can't stop a fire hose.

An overhead sign says "circulation: fluide", which means there are no accidents ahead requiring radical moves.

In the rear view, you spot a car in the fastest lane. You're not in the fastest lane. Not a problem, right ? The driver of the vehicle has been practicing on GTA5 on his computer. He does a four wheel slide across four lanes of traffic, because a "diagonal gap" opened in the fluide traffic. This was in preparation for using the off-ramp, coming up next.

That could be your daily drive coming home from work. One of the reasons that road is as thick with traffic as it is, is that is the major road for people going home. And your car has to be capable of moving in a "fluide" manner. No hay wagons allowed on there. Sure, it's not the autobahn, but when you test drive vehicles at the dealership, you're thinking of that road and the challenges. Absolutely nobody is moving out of your way when you merge in and enter the 120km/hr four lane firehose. There is no where for people to move, to accommodate you. And you buy a vehicle suited to the local conditions. In fact, I've never seen a transport even attempt to enter that particular section. Transport can take parallel secondary roads and enter where it thins out.

The road here isn't like that. But there are still too-short ramps to contend with. There was a crash at one of those too-short ramps in the last six months (someone rear ended on entering the highway). Normally, there is room to move over, if there was, say, a transport merging there. but you never know how people will be driving there, and how unreasonable they can be. People even speed in the fire lane at the mall here. There is no accounting for taste.

A car that takes 14 seconds to reach 60 MPH (the speed of that road), is not really a candidate. You need something slightly better. And a test drive will tell you whether it will fit with local practice or not.

Some of the BEVs don't have very high top-speeds. As a selection limit for me, anything less than 120km/hr would be out of the question, as that's what you need on any major highway here to be "fluide". Some roads have 110km/hr posted limits and we drive 120km/hr. If the car had a limit of, say, 108km/hr, then it would be a city car, and I wouldn't take it out on a major highway. That would be comfortable on an 80km/hr secondary road (one lane each way, not a divided highway). Any time those roads have black ice on them, they're a bastard (waiting for the car to recover and come back over the line). What you're trading there, by agreeing to drive on a secondary road, is your safety in deep cold winter days.

One of the cars I took for a test drive. the sales-person was a lady. We went out in the parking lot. She said "I'll drive". I didn't particularly like this (as I'm test driving these heaps for a reason), but I let her go ahead. The reason she wanted to drive, is she is a race car driver at weekend. Needless to say, we entered the ramp with *plenty* of merge speed to spare :-) At the traction limit on the grippy factory tyres. Most impressive. She should have brought her helmet and driving gloves, just for the theatre aspect of it :-) So that was my test drive. On my sheet of paper, I could tick "merging performance: Yes".

Paul

You may have noticed that this is a UK group. Perhaps our perspective is rather different.

In my experience the Nissan Leaf will accelerate and reach legal speed limits faster than my 2 litre Mondeo Mk 5.

Chris

short term power delivery from electric motors and lithium cells has never been a huge problem

Sustained high power levels however will overheat the motor and flatten the battery fast.

I guess thats either a D type or E type Jag ? - from that picture I cant see if the engine block is mounted at an angle

Might have been OE - I know that certain models of Hillman Hunter GLS were factory fitted with Holbay heads and dual Webers

Indeed it will. Acceleration is, in the real world, a short term condition.

I did spend my working life designing propulsion equipment for electric trains.

Chris

I had a mate who had an all-aggro. Had a puncture, jacked it up in the wrong place and the windscreen fell out. Seem it was a structural member, and far stronger than the tinfoil body.

As someone who has owned a few old cars (my current one will be 62 years old in March) I can confirm that neither SUs nor Strombergs have an accelerator pump.

Not all downdraft ones do. The Consul Classic had an accelerator pump, the Triumph Mayflower didn't.

From the factory the E-type came with three SUs, bigger ones for cylinders 1&2 and 5&6, because the slightly smaller one for 3&4 scavenged some additional fuel from the ones either side of it.

There were some interesting aftermarket conversions. My brother bought a mini (the original Issigonis design) and discovered that there was no inlet manifold; each cylinder had its own Amal Monobloc carburettor (normally only seen on motorbikes of that era). It took quite a while to get them all singing exactly the same song, but having got them perfectly tuned the car went like stink - flat out in top saw the speedometer needle against the other side of the stop below 0mph.

On Tue, 23 Dec 2025 20:39:42 +0000, Scott snipped-for-privacy@gefion.myzen.co.uk> wrote: [snip]

In another random thought, I wondered why electric cars seem to have two batteries - the lithium ion traction battery and a traditional lead acid battery. Would it not be a better use of space to have just one battery? Also, how does the lead acid battery get charged?

A lot of the accessories still run off 12V and this is supplied by a DC/DC converter (which charges the 12V battery) from the HV traction battery. You need a secondary battery to close the HV contactors that allow power through to all the other systems.

It doesn’t have to be a 12V lead acid battery though. They are the most common but manufacturers are beginning to use smaller lithium batteries in their place to supply 12/24 or more volts for the accessories.

Tim

In my Nissan Leaf the 12V lead acid battery is charged by the solar panel built into the roof but while locked in my garage it's charged from the traction battery.

It also means all the usual things you do with 12v still work. eg if it goes flat you can jump start it in the normal way (not actually to turn over the starter motor, but to provide enough power to turn on the high voltage system). The computers need to check everything is happy before they enable HV power and they run off 12V.

The Cybertruck uses 48V instead and had to do lots of hacks to interface with the 12V world, such as the ability to jump from a 12V lead acid in an emergency.

Theo

Could you explain this a bit more. I believe the supply voltage is typically 400V (Nissan Leaf), so surely a 12V battery will not cut the go very far?

Why is that? 230V seems fine in the home.

As previously explained, it powers the computer and other accessories that enable the HV battery to be “turned on”. It doesn’t drive the car.

Your 12V battery won’t drive an ICE car far if the engine doesn’t start. ;-)

Houses rarely crash. Also, every single accessory in the car would need to be re-engineered to operate off of the higher voltage. Far easier and cheaper to use motors, fans, bulbs, radios etc that have been designed for

Tim

Cars like my Renault as you would expect use almost all the same components as the same company's ICE cars, the battery, motor and its control system just drop in instead of the engine. In the same way as you start/stop the engine you switch on/off the electric drive (my last EV even had the same "Motor Start/Stop" control as its ICE stable-mates).

The only things in mine powered from the 400V are the traction drive, the motor for the heat pump and the charger for the 12V battery. All of these are disabled when the drive is switched off (= ignition off).

nib

I must be missing something. I thought you were discussing the proposition: "eg if it goes flat you can jump start it in the normal way (not actually to turn over the starter motor, but to provide enough power to turn on the high voltage system)".

Did you mean a flat traction battery or a flat 12V battery? If the traction battery is flat, how can it 'turned on' and how can it drive a car? If you mean the 12V battery is flat, my understanding is that it cannot drive the car anyway.

I don't disagree with that but once an ICE engine starts, it can usually keep going. If an electric car starts and the battery if flat, it won't be going anywhere.

Okay.

I hadn't thought about that aspect. Is this the Renault 5? What do you think of it? I'm looking at its stablemate, the Nissan Micra, but I think the all-round vision is very restricted.

'Tis the Renault 5. Very pleased with it so far. Took a little while to get used to the "gear lever" being just above the wiper stalk!

One feature might put some people off: Renault are very much in bed with Google. It uses Google maps, Google voice recognition and lots of other stuff and can link to your Google account. Sometimes its a bit spooky to do a search on Google Maps at home then have the car suggest that place as a destination the next time you go out!

nib

You can’t.

See above about the DC/DC charger. It’s the EV equivalent of an alternator.

Tim