Are we on the brink of an electric car revolution?

Our transport is heavily oil-based. What are the alternatives?

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kenneal - lagger
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Re: Are we on the brink of an electric car revolution?

Post by kenneal - lagger »

The internal operating temperature for the LMP® battery is between 60°C and 80°C. ...............................

R & D on the LMP® battery is continuing to lower its internal operating temperature while increasing its autonomy.
Would this high operating temperature reduce the overall efficiency of the battery and reducing it raise the efficiency?
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Re: Are we on the brink of an electric car revolution?

Post by clv101 »

You'd think so as it'll be losing a few hundred watts to maintain that temperature. On the flip side, maybe that heat can be captured to heat the cabin, windscreen, mirrors etc, which in cold weather takes power.
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Re: Are we on the brink of an electric car revolution?

Post by kenneal - lagger »

clv101 wrote: Sat Feb 06, 2021 3:30 pm You'd think so as it'll be losing a few hundred watts to maintain that temperature. On the flip side, maybe that heat can be captured to heat the cabin, windscreen, mirrors etc, which in cold weather takes power.
A like button would be useful for quick agreement.
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Re: Are we on the brink of an electric car revolution?

Post by adam2 »

kenneal - lagger wrote: Sat Feb 06, 2021 1:53 pm
The internal operating temperature for the LMP® battery is between 60°C and 80°C. ...............................

R & D on the LMP® battery is continuing to lower its internal operating temperature while increasing its autonomy.
Would this high operating temperature reduce the overall efficiency of the battery and reducing it raise the efficiency?
If the battery is in regular use, then I would expect that the small but real losses in the battery would keep it at the optimum operating temperature. It would probably need thermal insulation to retain the heat when needed, and fan cooling to remove the heat when it would otherwise be excessive.

If however the battery was unused for a significant time, without any losses, then it would slowly cool and might require energy input to keep it hot.

A lot would depend on how important is the stated optimum temperature. If the battery stops working below 60 degrees then heat input would be important when it was standing idle.
If however the battery still worked, but less effectively down to say 20 degrees, then heating it would be less important. A vehicle with a charged battery that stood unused for a while could still then be driven, presumably with reduced range or performance. The losses during this discharge would soon warm the battery towards the optimum. Charging it would add more warmth.

If a low temperature permanently killed the battery, then that is a significant disincentive for use in private cars.
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Re: Are we on the brink of an electric car revolution?

Post by Potemkin Villager »

Yes it is a strange one this as many engineering issues usually revolve
around limiting the temperature rise of components over a specified
range of operating temperatures. It does sound as if these devices would work better
in Saudi Arabia rather than Greenland!

It seems that they have been trying to get the required operating temperature
down toward more usual ambient temperatures for sometime......
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Re: Are we on the brink of an electric car revolution?

Post by Potemkin Villager »

Jasper Jolly (sic) boosting EVs with some dubious comparisons and assertions in the Grauniad.

https://www.theguardian.com/business/20 ... ctric-cars

e.g. “Over its lifetime, an average fossil-fuel car burns the equivalent of a stack of oil barrels 25 storeys high. If you take into account the recycling of battery materials, only around 30kg of metals would be lost – roughly the size of a football.”

and

"A calculation of the resources used to make cars relative to their weight shows it is at least 300 times greater for oil-fuelled cars."

even:-

"T&E calculations suggest that battery electric cars will use 58% less energy than a petrol car over its lifetime and emit 64% less carbon dioxide."
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Re: Are we on the brink of an electric car revolution?

Post by kenneal - lagger »

adam2 wrote: Sat Feb 06, 2021 5:43 pm
kenneal - lagger wrote: Sat Feb 06, 2021 1:53 pm
The internal operating temperature for the LMP® battery is between 60°C and 80°C. ...............................

R & D on the LMP® battery is continuing to lower its internal operating temperature while increasing its autonomy.
Would this high operating temperature reduce the overall efficiency of the battery and reducing it raise the efficiency?
If the battery is in regular use, then I would expect that the small but real losses in the battery would keep it at the optimum operating temperature. It would probably need thermal insulation to retain the heat when needed, and fan cooling to remove the heat when it would otherwise be excessive.

If however the battery was unused for a significant time, without any losses, then it would slowly cool and might require energy input to keep it hot.

A lot would depend on how important is the stated optimum temperature. If the battery stops working below 60 degrees then heat input would be important when it was standing idle.
If however the battery still worked, but less effectively down to say 20 degrees, then heating it would be less important. A vehicle with a charged battery that stood unused for a while could still then be driven, presumably with reduced range or performance. The losses during this discharge would soon warm the battery towards the optimum. Charging it would add more warmth.

If a low temperature permanently killed the battery, then that is a significant disincentive for use in private cars.
Sounds like the Lion battery might need a lead acid starter battery!!

Ah!! The irony!!

Or be like an insect or reptile and have to bask in the sun for a while in the morning before getting going.
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Re: Are we on the brink of an electric car revolution?

Post by PS_RalphW »

All electric cars have a conventional lead acid battery to control and power the normal 12v electrics on the car. It is charged from the main battery by a transformer. It could be a different chemistry but wjy change what works? Lead is the most completely recycled element, which is just as well given how toxic it is.
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Re: Are we on the brink of an electric car revolution?

Post by PS_RalphW »

The government is showing it's "green" credentials again.

After freezing duty on petrol and diesel (yet again) they have with immediate effect cut the electric car subsidy from £3500 to £2500 and slashed
the upper cut off list price from £50,000 to £35,000 for a purchase to qualify.

This removes at least 3/4 of the current purchase options from the subsidy.

My (big battery) version of the Nissan Leaf has just lost the subsidy.
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Re: Are we on the brink of an electric car revolution?

Post by clv101 »

I think cutting the threshold from £50k to £35k is a good move. People in the market for a £50k car should not be receiving public subsidy. As I understand it the total pot hasn't shrunk so these changes mean more cars will be supported, for a longer period of time, with manufacturers receiving a slight incentive to focus on sub-35k cars.

I bet the next version of big battery leaf will be back in subsidy territory.
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Re: Are we on the brink of an electric car revolution?

Post by kenneal - lagger »

I expect that a lot of the car companies make a bigger percentage and absolute profit on larger cars so that would be part of the drive towards protest from that quarter.
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Re: Are we on the brink of an electric car revolution?

Post by Potemkin Villager »

https://www.theguardian.com/technology/ ... eat-police

“There was no one in the driver’s seat,” Sgt Cinthya Umanzor of the Harris County Constable Precinct 4 said of the crash on Saturday night. The 2019 Tesla Model S was traveling at high speed when it failed to negotiate a curve and went off the roadway, crashing to a tree and bursting into flames, local television station KHOU-TV said."

Apart from anything else I ask myself what is it in an EV that caused the car to burst into flames? :roll:
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Re: Are we on the brink of an electric car revolution?

Post by adam2 »

If lithium batteries are grossly abused, as in a major impact, they can catch fire.
As can tanks of petrol.

This accident would seem to result from regarding the "driver assist" feature as being "fully automatic" and not be directly related to the power source.
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Re: Are we on the brink of an electric car revolution?

Post by PS_RalphW »

There is a 'lane assist' feature in my Nissan Leaf. It is of limited use because you need to keep your hands on the wheel or it cuts out, and on real world roads it tends to cut out without warning or obvious cause. It is only designed to work on multi-lane roads, and has a tendency to drift closer to the lane edges than I like, especially in busy traffic. I end up monitoring the performance of the lane control, and less focused on the road ahead. Switching mentally between monitoring and controlling the steering can become an issue in itself. I do not know how sharp a turn I trust it to follow.
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Re: Are we on the brink of an electric car revolution?

Post by johnny »

kenneal - lagger wrote: Mon Mar 01, 2021 2:13 pm Sounds like the Lion battery might need a lead acid starter battery!!

Ah!! The irony!!
My Lion battery in the car has a lead acid starter battery. Both of them. Is this weird or normal?
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