Newbie researching RAV4 PHEV

[Toomanytoys]

Yeah, the Kona with a bit more Battery capacity would be great.. 

[Cyker]

Yes, and also with less fire  

[Toomanytoys]

??? 

Do they have Vauxhall Setonfira issue??

[Nick72]

2 hours ago, Cyker said:

Haha I love stuff like that! Never been one for shouty cars, best kind are the unassuming innocent looking sh-err-!Removed! boxes that are hiding a monster underneath  

 

As for EVs, the tech level is already more than adequate and, IMHO, we don't really need many more advances - Electric motors are already mid-high-90's in terms of power conversion efficiency; The power electronics like the inverters and such could do with a bit more improvement, but the incredibly high-speed processing power and solid state electronic switching we have had for decades means that's mostly just iterating software tweaking and sensors now.

The main reason a lot of newer EV's have increasingly worse efficiency is not the tech, it's the manufacturers making them big and heavy and brick-like, and loading them with electronic garbage that has nothing to do with driving. The Kona could do 5 miles/kWh (Which is very good!) and that came out ages ago, so it can be done with the tech we already have.

The single thing holding EVs back is the energy storage part - Batteries are still garbage for energy storage compared to chemical fuels; I think it's in the region of 2 orders of magnitude (i.e. 100x) worse, which is why even with the 20-30% conversion efficiency of a petrol engine they can still go further and faster than EVs, and when you get insane things like the new TNGA Toyotas that can average 40% or diesels that get into the 50%'s it makes it even more challenging.

The funny thing is EV's will never need to carry as much energy, as their conversion efficiency is so much higher, but even so just getting them into the same ballpark with so little has still proven harder than I thought it would...

We just really need either a major breakthrough in battery tech or some out of left-field energy storage or generation system - A 2x-3x improvement would make EVs work for everyone. Or just keep digging at those small percentage increases and hope eventually they add up!

Definitely going to get there. No science or technology blockers. I don't entirely agree on the motor tech front since if you can have a 150hp motor that weighs 20kg rather than 70kg and there are two of them then that's a 100kg saving. 

Agree on the manufacturing front. It's driven by cost and some lazy old fashioned thinking. That's partly due to ICE mindsets and the failure to employ the new design freedoms afforded by electric. That's changing, I'm already looking at replacement cars for the R4P since I need to put an order in about 18 months from now. Looking at the BMW i50. 500plus hp. True fast charging (if you can find a compatible charger!). 370 mile range I think and it looks like most of that is real based on the reviews. 100k though which is way too pricey at the moment! 60k and it's a deal!

[Nick72]

9 hours ago, Flatcoat said:

I don’t mean theoretical academic papers, I am talking about engineered prototypes with technology that is scalable for mass production. There are dozens of ideas and abandoned prototypes littering automotive history. There are also plenty of papers and manufacturers saying all the major efficiency improvements are now achieved. Any future improvements are going to be very small and incremental, 0.2% here and 0.3% there, if lucky. And raw material costs are rising exponentially as China buys up all the resources. 

I'd check out the R and D. Start with the science then the tech then the engineering then the economics in the PESTLE context. Political environmental sociological technological legal and environmental. 

Not my own research which was backed by the fellow engineers in my firm and Imperial College Profs. But what the manufacturers are saying too. Well aware of the difference. Have been behind a lot of this stuff making in real for 3 decades. Not just theorizing. 

New BMW i50 now does c. 370 miles. In 2 years someone will top that. And so on. 10 years we'll be there or abouts. Small gains which add up.

Add in the revolutions emerging in chemistry (which are actually making things simpler to manufacture and more sustainable) and we could see significant increases beyond the x3 I mention.

 

Only time.

[Cyker]

2 hours ago, Nick72 said:

I don't entirely agree on the motor tech front since if you can have a 150hp motor that weighs 20kg rather than 70kg and there are two of them then that's a 100kg saving. 

 

Ooh good point, I always forget about the motor mass! I guess all the power electronics could benefit from some weight reduction too, esp. as if they can make them more efficient, they'll dissipate less heat so they won't need such hefty heatsinks and just less mass wasted for cooling overall!

 

3 hours ago, Toomanytoys said:

??? 

Do they have Vauxhall Setonfira issue??

I was half-joking, but yeah they and GM are in the middle of a massive Battery recall on the Bolt EV and Kona due to what they claim is a manufacturing fault in their batteries which is causing them to randomly catch fire.

Really tho', it's only a small percentage of cars that have actually caught fire, and I personally am very suspicious that it isn't a manufacturing fault at all (Or rather, that the manufacturing fault they've identified is makes it more susceptible, but isn't the actual cause.).

The one thing that the Kona and Bolt have in common is they have a much higher range to Battery capacity than anyone else - I thought they were just much more efficient, and while that's partly true, it turns out they're also using much more of the full Battery capacity than anyone else, and I think that's caused the batteries to degrade much faster than everyone else's into the "oh dear fire" zone.

It's like why laptop batteries die after maybe 2 years but the Toyota hybrid cells are still fine after 10+ years - Laptop batteries get run from 100% to 0% and back repeatedly, and this uses up their limited full charge-discharge cycles very quickly, but Toyota hybrids keep the battery charge in the middle 60%, and even tend to stick around the middle of *that* - These smaller partial-charge cycles degrade the battery at a much slower rate than a full-charge cycle, and even keeping the battery around that 50% mark for most of its life greatly increases its longevity. (Storing a battery near 100% or 0% causes it to degrade faster vs around 50%)

 

[ernieb]

The Toyota PHEV traction Battery also never really gets much below 30% and although it says It's been charged to 100% US reviewers who've connected a OBD port charge recorded say it only actually gets to around 96%. 

[Flatcoat]

The aspect of all this that is overlooked is the ‘bandwidth’ of vehicle uses in the UK and beyond. I tow a caravan and often very long distances. This year we have holidays planned which involve respectively 350, 450, 1000 mile trips each way. With an ICE car I only need to fill up once on the shorter trips and 3 times on the longer. With EV I would be fully recharging once every 100-125 miles. And that assumes their is free working charger that I can pull in without uncoupling my caravan. Problem, they don’t exist. My brother runs an engineering company that often involves emergency call out journeys of 2/300 miles. He can’t hang about waiting hours to recharge his van every 100 miles. Can you see a hill farmer in the Scottish highlands running an EV landrover rescuing his sheep in winter? I am not against EV’s but I don’t wear rose tinted glasses that other equally valid power sources do not exist and should be equally supported by govt policies and legislation. Let the markets decide. 

[Toomanytoys]

Yeah and it seems LPG is being abandoned... Which is a real shame as it is lower emissions and is a waste product of the oil industry.. they will just turn the burners up... what a waste..  (I have run one of my classics on LPG for the last 18 years.. and was covering 10k+ a Year)

[Roy124]

In India, 25 years ago I was surprised at the number of cars running LPG.  Not LPG conversions but dual fuel.  A gas cylinder in the boot, a changeover switch on the dash.  Never pass construction and use regulations. 

Fuel must have been very expensive as there were continuing suggestions to add sea water too.  Tuk Tuk drivers carried their fuel in one litre bottles never filling the tank.  It was either an anti theft precaution or an unwillingness to pass to much unused fuel to the next driver. 

 

 

 

 

[Nick72]

On 2/3/2022 at 8:01 AM, Flatcoat said:

The aspect of all this that is overlooked is the ‘bandwidth’ of vehicle uses in the UK and beyond. I tow a caravan and often very long distances. This year we have holidays planned which involve respectively 350, 450, 1000 mile trips each way. With an ICE car I only need to fill up once on the shorter trips and 3 times on the longer. With EV I would be fully recharging once every 100-125 miles. And that assumes their is free working charger that I can pull in without uncoupling my caravan. Problem, they don’t exist. My brother runs an engineering company that often involves emergency call out journeys of 2/300 miles. He can’t hang about waiting hours to recharge his van every 100 miles. Can you see a hill farmer in the Scottish highlands running an EV landrover rescuing his sheep in winter? I am not against EV’s but I don’t wear rose tinted glasses that other equally valid power sources do not exist and should be equally supported by govt policies and legislation. Let the markets decide. 

Yep, agree with that. EVs don't work for longer trips or towing so much. They will though 😉