Electric Cars Discussion

[Guest rmpfyf]

Now for some classic EV notes. This was the EV-95, the original nickel metal hydride battery made for the GM EV1, Toyota RAV4 EV, Ford Ranger EV... then the rights were purchased by Chevron, who sued anyone wanting to use them (including Toyota) and wouldn't let EVs be made with the tech. 

 

http://www.evnut.com/rav_battery_data_sheet.html

 

20+ years ago! The tech's moved on considerably since.

[aussievintage]

7 hours ago, rmpfyf said:

All very normal and there's practically zero maintenance. Runs at much lower temperatures than a ICE cooling system for a start, and there's much less thermal load generally. Closed systems. 

 

I thought you mentioned coolant flush in a recent post as a maintenance procedure?  Maybe I misunderstand what you mean by "closed system".  If it was more like a refrigeration system that never needs regassing, I would be more comfortable with the idea.

 

 

8 hours ago, rmpfyf said:

Liquid cooling for electric motors has existed long before electric cars. A very mature and robust technology - much easier than oil in a combustion engine, there's zero vibrations involved

 

Seems the different manufacturers are trying different ways to do it, so it isn't so mature that it can't be improved.  Good that they are trying though.

[Addicted to music]

Cooling is absolute essential to the life of components where it be mechanical or electrical.     The critical manufacturing here is that the process gets checked and tested before it goes into the vehicle.  Any blocked channel will result in catastrophic failure.    You can’t rely on QC from the suppler themselves as Toyota does.  Toyota Australia had shifted there QA and place it directly onto the supplier.  They would test a quantity out of the batch supplied,  if a fault was detected the whole batch would be rejected.    The most unfortunate compromise here is that if a fault wasn’t detected in the sample quantity, it would passed into the assembly process, by the time a fault is reported at this stage, it’s too late,   This could be anywhere up to 1000s of vehicles already assembled,     The bosses Camry when I 1st picked up had this issue.  I picked it up in June 2003 late in the evening after work!  The heater wasn’t working, it was returned on Monday to the dealer and they had to stripped the entire engine compartment and also had Enginners from Toyota direct.  1 and 1/2 weeks later the dealer made the decision to replaced the vehicle, so it was swop with another brand new one.   They then found out that the channel in a return was not formed correctly resulting in coolant not getting into the heater to heat the cabin.  Whatever part where the channel wasn’t formed is now in the training section of Toyota for faultfinding.  

 

Here’s a look at the Tesla vehicle on cooling: 

 

 

[aussievintage]

13 minutes ago, Addicted to music said:

Cooling is absolute essential to the life of components where it be mechanical or electrical.

Of course it is.  Note, I said I did not like liquid cooling - i.e. the horrors of typical ICE radiators and cooling jackets on motors with circulating coolant that needs to be topped up, and replaced periodically, and associated corrosion of metal parts, and the perishing of rubber hoses, and the wearing out of pumps.

 

16 minutes ago, Addicted to music said:

The critical manufacturing here is that the process gets checked and tested before it goes into the vehicle.  Any blocked channel will result in catastrophic failure.

 

Yes, and that failure can happen down the track as things begin to age.  Some of the cooling channels shown in that video were tiny and could easily block.   Typical air cooling systems are much more reliable, IF (and it appears to be a big IF) systems can be designed to be adequately cooled that way.

[proftournesol]

1 hour ago, aussievintage said:

 

 

Yes, and that failure can happen down the track as things begin to age.  Some of the cooling channels shown in that video were tiny and could easily block.   Typical air cooling systems are much more reliable, IF (and it appears to be a big IF) systems can be designed to be adequately cooled that way.

 

One of the reasons that early Leaf batteries had such a short life was that they were air cooled, and, clearly, inadequately cooled

[Addicted to music]

3 hours ago, aussievintage said:

Of course it is.  Note, I said I did not like liquid cooling - i.e. the horrors of typical ICE radiators and cooling jackets on motors with circulating coolant that needs to be topped up, and replaced periodically, and associated corrosion of metal parts, and the perishing of rubber hoses, and the wearing out of pumps.

Agreed, there is a fare set of maintenance on liquid cooling, even the type of coolant used to whats recommended.   

 

3 hours ago, aussievintage said:

Yes, and that failure can happen down the track as things begin to age.  Some of the cooling channels shown in that video were tiny and could easily block.   

No surprise here,  any design will show up issues as it ages.  

3 hours ago, aussievintage said:

Typical air cooling systems are much more reliable, IF (and it appears to be a big IF) systems can be designed to be adequately cooled that way.

Air cooling is inefficient and doesn’t not mean it’s maintenance free.  Depending on what’s deployed can also require maintenance periodically, at least with active cooling and using liquids you can control the cooling efficiency (temp monitoring and pump rate).   There are no free lunch in any design. 

[Guest]

apologies if a little off topic but autonomous vehicle technology has links to EV development  - I like the idea that tinkerers are still involved ;-)

 

NY Times article on autonmous racing

[aussievintage]

5 hours ago, proftournesol said:

One of the reasons that early Leaf batteries had such a short life was that they were air cooled, and, clearly, inadequately cooled

The other way of saying that is that they produced way too much waste heat.  You can solve that 2 ways.  You can apply lots more cooling via liquid cooling systems, or develop better batteries and electronics that give off less heat.  As wasting energy as heat makes it less efficient anyway, the second method is MUCH preferable.

[aussievintage]

2 hours ago, Addicted to music said:

Air cooling is inefficient and doesn’t not mean it’s maintenance free.  Depending on what’s deployed can also require maintenance periodically, at least with active cooling and using liquids you can control the cooling efficiency (temp monitoring and pump rate).   There are no free lunch in any design.

My experience with air cooling in electronics, and in motorbikes and VW cars, is that it is WAY less maintenance intensive.

[proftournesol]

1 hour ago, aussievintage said:

The other way of saying that is that they produced way too much waste heat.  You can solve that 2 ways.  You can apply lots more cooling via liquid cooling systems, or develop better batteries and electronics that give off less heat.  As wasting energy as heat makes it less efficient anyway, the second method is MUCH preferable.

The other way to reduce heat is to charge at a slower rate. You can't have it both ways, take 48 hours to recharge your car and you can probably get good battery life and low heat, charge quickly and you need more robust heat management

[Addicted to music]

53 minutes ago, aussievintage said:

My experience with air cooling in electronics, and in motorbikes and VW cars, is that it is WAY less maintenance intensive.

Agreed,

 

but not all air cooling is maintenance free.  Heat sink fins gets clogged with dust that has to be cleaned out. Fans have to be checked to ensure they are working properly.   In some sensitive electronic areas only a grounded vacuum cleaning can be used.    Some of the stuff I work on has ozone and dust filters that has to be either maintained or replaced.  In areas of extraction, some fans fail and stops the product from functioning, because  an error code is generated as all fans employed have a active for monitoring to tell you its failed.

[aussievintage]

1 minute ago, proftournesol said:

The other way to reduce heat is to charge at a slower rate.

Quite true.

 

1 minute ago, proftournesol said:

You can't have it both ways, take 48 hours to recharge your car and you can probably get good battery life and low heat, charge quickly and you need more robust heat management

True.  But improve the losses and waste heat in the basic battery design, then you can again charge more quickly.  I am sure they are working very hard on this.

[Addicted to music]

3 minutes ago, proftournesol said:

The other way to reduce heat is to charge at a slower rate. You can't have it both ways, take 48 hours to recharge your car and you can probably get good battery life and low heat, charge quickly and you need more robust heat management

With your Tesla, does it give you a temperature reading on the battery, motor etc.

[aussievintage]

2 minutes ago, Addicted to music said:

but not all air cooling is maintenance free.  Heat sink fins gets clogged with dust that has to be cleaned out.

 

much easier than cleaning a clogged water jacket or radiator.

 

2 minutes ago, Addicted to music said:

Fans have to be checked to ensure they are working properly.   In some sensitive electronic areas only a grounded vacuum cleaning can be used.    Some of the stuff I work on has ozone and dust filters that has to be either maintained or replaced.  In areas of extraction, some fans fail and stops the product from functioning, because  an error code is generated as all fans employed have a active for monitoring to tell you its failed.

 

Similar error codes will exist for the liquid cooling systems, and they too will stop the product from functioning. 

[crisis]

On 10/04/2019 at 10:21 PM, rmpfyf said:

Sure... which still means you're paying more for electricity when investment is required!

We weren't directly before privatisation. It was "general revenue". Our registration or fuel tax doesn't go up in direct relationship to more roads being built. More of our tax may have been directed to such things but prices didn't go up as a direct result.

 

 

On 14/04/2019 at 3:13 PM, Wiredin said:

Just on electric vehicles in general; are they really more eco-friendly than conventionally powered vehicles? When one takes into consideration the manufacturing process....very similar for both I'd imagine....and the fact that the electricity generated to power them is still (by and large),  produced by coal-fired power stations.

NOW. Even this article which starts out with a headline sounding like a condemnation of electric vehicles curiously says that they can and most likely will be "more eco friendly". Perhaps the proof readers hard on for trashing anything "green".

https://www.bloomberg.com/news/articles/2018-10-16/the-dirt-on-clean-electric-cars?fbclid=IwAR0hGPM34HyMVsR2DKGR6AL90aUeL2tKuQrwtQTk6wkaf0utbvrZTKR-ycQ

 

 

 

On 14/04/2019 at 3:13 PM, Wiredin said:

 

Then there is the very considerable problem of charging....it takes many hours to fully power an electric vehicle compared to the few minutes it takes to fill up at a petrol station. Then again, where are the charging stations? What about unit blocks with on-site parking? How would electric vehicles be charged in these situations, or those many of us who have to park our vehicles on the street...how would we be able to charge?

Depends if you only read the popular scare campaign kind of "facts".

https://www.smh.com.au/national/don-t-buy-the-scare-against-electric-vehicles-20190409-p51cea.html?btr=7dd84db7caca5c2a208d686e0fd13c1b&fbclid=IwAR101rYkDgPiNQQk5cbmcUTg3uFG7JPNSJNn_c3B9JptdPrZlyA1y5CmmJs

 

On 14/04/2019 at 3:13 PM, Wiredin said:

I wouldn't touch one, personally. It may give the deep-greens among us a warm inner glow, but out here in the real world, electric vehicles are the stuff of dreams/nightmares.

 

 

 

[Guest rmpfyf]

1 hour ago, Addicted to music said:

With your Tesla, does it give you a temperature reading on the battery, motor etc.

Don't think production cars have it though it's certainly logged at many points on the battery. So does Toyota and many other vendors - it's common to any modern battery management system and general thermal management system.

[Guest rmpfyf]

1 hour ago, aussievintage said:

But improve the losses and waste heat in the basic battery design, then you can again charge more quickly.  I am sure they are working very hard on this.

 

Wait for solid state batteries.

 

In the meantime people are going nuts on liquid immersion and refrigerant-cooled batteries, though this adds complexity.

[Guest rmpfyf]

4 minutes ago, crisis said:

We weren't directly before privatisation. It was "general revenue". Our registration or fuel tax doesn't go up in direct relationship to more roads being built. More of our tax may have been directed to such things but prices didn't go up as a direct result.

 

Disagree. Our price rises in the 80's certainly did go up as electrical infrastructure was created, in particular with regard to distribution costs. A decrease in demand would have hit us equally so. 

 

SECV's PL wasn't listed under general revs. 

[Guest rmpfyf]

14 hours ago, Wiredin said:

@rmpfyf Thank you for your thoughtful and truly excellent post. As I said, I'm not opposed to EVs, I just think that for the majority if us, they are not worth considering at this point in time. Cheers.

 

Anytime. And you're right, they're not. Though there's a place for the excitement and interest around 'em - and in the event you've $20k kicking around for an around-town car... you can even get started. If you had better places to spend $20k I'd understand similarly  

[crisis]

7 minutes ago, rmpfyf said:

 

Disagree. Our price rises in the 80's certainly did go up as electrical infrastructure was created, in particular with regard to distribution costs. A decrease in demand would have hit us equally so. 

 

SECV's PL wasn't listed under general revs. 

Is there any way to directly correlate that? Prices go up but government departments dont charge more tax (which is where the "price" comes from) to directly fund infrastructure.

[Guest rmpfyf]

10 hours ago, aussievintage said:

I thought you mentioned coolant flush in a recent post as a maintenance procedure?  Maybe I misunderstand what you mean by "closed system".  If it was more like a refrigeration system that never needs regassing, I would be more comfortable with the idea.

 

Seems the different manufacturers are trying different ways to do it, so it isn't so mature that it can't be improved.  Good that they are trying though.

 

On one hand the coolant doesn't get as hot as it would in an ICE so it lasts much longer on a molecular level, in addition to not mixing with oil through head gaskets etc. In all honesty the mix is usual 50/50 ethlyene glycol - which Tesla doesn't make - so how long it'll last is really down to what the chemical manufacturer will rate it for. When last I checked it was a change at 4 years or 48,000 miles. Brake fluid, that's a consumable too. I'm sure you get the deal. The car has a coolant tank as you'd expect doing all the usual stuff and a bit more. 

 

The actual system design on the Model S was parallel/series - a coolant loop for the battery, another for the powertrain, and a four-way valve to run them parallel or series depending on the thermal situation. Air inlets were on active shutters to change thermal load and drag. One of the loops had a chiller to utilise the refrigerant system (shared with cabin air). It all worked pretty well, though it's been vastly simplified and better integrated on Model 3. 

 

In retrospect it wasn't so different from usual practice, just applied differently and with some good innovations along the way. 

[aussievintage]

22 minutes ago, rmpfyf said:

a coolant loop for the battery, another for the powertrain, and a four-way valve to run them parallel or series depending on the thermal situation

I presume that means they can heat the batteries with some motor heat when outside temperatures are too low.  If so, smart, way better than resistive heaters.

 

24 minutes ago, rmpfyf said:

On one hand the coolant doesn't get as hot as it would in an ICE so it lasts much longer on a molecular level, in addition to not mixing with oil through head gaskets etc. In all honesty the mix is usual 50/50 ethlyene glycol - which Tesla doesn't make - so how long it'll last is really down to what the chemical manufacturer will rate it for. When last I checked it was a change at 4 years or 48,000 miles.

That's pretty good, I must admit.

 

25 minutes ago, rmpfyf said:

Brake fluid, that's a consumable too.

Another subject I was interested in. Regenerative braking.  Hoping hydraulics will become a thing of the past too.

 

28 minutes ago, rmpfyf said:

In retrospect it wasn't so different from usual practice, just applied differently and with some good innovations along the way. 

I am seeing Tesla as doing some interesting things.   I wonder about other technologies - like in-wheel motors.  Anyone still looking at that seriously?

[Guest rmpfyf]

26 minutes ago, aussievintage said:

I presume that means they can heat the batteries with some motor heat when outside temperatures are too low.  If so, smart, way better than resistive heaters.

 

Yes, that's correct. In extreme cases some other heat source it used (typically an engine block heater or, in extreme conditions, Volvo was noted for using an ethanol-fired heater) typically because ethylene-glocol mixtures turn to a viscous sludge around zero Celsius or below, and that's not particularly good for anything (pumps in particular). So it pays to have some heating. But yes, the motor can be made to do some of this. 

 

26 minutes ago, aussievintage said:

That's pretty good, I must admit.

 

Indeed so - there's a lot less to maintain generally. 

 

26 minutes ago, aussievintage said:

Another subject I was interested in. Regenerative braking.  Hoping hydraulics will become a thing of the past too.

 

Unlikely to complete go given safety requirements, the fact that regen available depends on how much the vehicle can take at any time (which varies to a level that's unacceptable as a sole braking force supply at the moment) and needed braking forces tend to be quite high. 

 

But there's some interesting stuff going. Early Model S (at least) had bigger brake discs on the rear than the front, to give you some idea of force distribution after regen effects. And whilst first high regen experiences tend to have people feeling like the've just had their heads ripped off, you quickly adjust and almost always want more, and then going back to a car without regen feels like riding a two stroke for the first time in a while, you lift of the throttle and your brain goes somewhere between 'so much wasted energy' and 'oh f*** I need to brake'. 

 

26 minutes ago, aussievintage said:

I am seeing Tesla as doing some interesting things.   I wonder about other technologies - like in-wheel motors.  Anyone still looking at that seriously?

 

 

To be fair to most players Tesla is leading in much of the 'interesting things' department. Most don't realise that their creation of a vision systems chip business allows them to deliver that particular solution at vastly lower power, and accordingly more range. Tesla can do a lot of things just because it's largely vertically-integrated; traditional vendors need to work through a traditional supply chain... which just takes longer. Sometimes a lot longer, which can be a disadvantage - it's not all disadvantages though. Tesla certainly is a first mover in the space though. 

 

In-wheel motors are good though can be restrictive for packaging, and add unsprung mass (handling potential isn't as nice). Can't pack quite as much cooling either. 

 

This said it hasn't stopped a bunch of students using modified conveyer-belt motors to make very fast EVs... the following is just one example. We have local teams doing this too!

 

 

[Guest rmpfyf]

2 hours ago, crisis said:

Is there any way to directly correlate that? Prices go up but government departments dont charge more tax (which is where the "price" comes from) to directly fund infrastructure.

 

No correlation applies, you're assuming energy prices were regulated. They weren't. The SECV gave some large customers very favourable discounts (e.g. Alcoa - remember the Portland Smelter Contract, which the Cain govt used to - laughably - set energy prices to aluminium prices? You and I paid for that) at the expense of others (like us). They had dividends to return (the bit which affected taxes) and debts to service (which served more to set costs). As in prices started to rise because we built a lot of new generation and transmission - which happened to be brown coal, displacing earlier black coal plants shipping fuel in from NSW - and we had to pay those debts in addition to service deals our govt cut with friends.

 

We now have more variable demand, less big customers, we put a value on renewables, we understand that carbon costs society in many ways enough to want to not make every energy source high carbon (seriously, for a while there VIC lead the world in carbon intensity, not a good thing to have) and because of so many people wanting to live here we actually need to invest in generating more and transmitting/distributing more. And to stop us investing in excess capacity we really don't need, we needed to similarly invest in projects to connect state grids. Which is happening all over the world. And whilst smarter it's not free either.

 

I'm not suggesting it was all bad and privatisation all good - certainly some aspects have been laughable for the public interest (in my opinion deregulating distribution was wrong, and I think market rules allow too much for capacity withholding - I'm sure we've each our thoughts here) - though anyone thinking we'd be instantly better off in some prices-wouldn't-have-risen-if-nothing-were-privatised land is kidding themselves.

[aussievintage]

1 hour ago, rmpfyf said:

In-wheel motors are good though can be restrictive for packaging, and add unsprung mass

I was reading here https://spectrum.ieee.org/transportation/advanced-cars/protean-electrics-inwheel-motors-could-make-evs-more-efficient    about some testing done for Protean by Lotus, that suggests the unsprung mass problem may not be a show stopper.

 

I really like the idea from the all wheel drive stability side of things.  I have an AWD car and the stability when towing a caravan is amazing.  Had a flat on the van and could hardly tell - just  a bit of vibration like the road surface was rough.  Doing that with electronically controlled motors would be even better.

 

1 hour ago, rmpfyf said:

regen available depends on how much the vehicle can take at any time

Can't they dump the excess into resistive load if the batteries can't take it all?  Too much energy to dissipate maybe?