Thread: Future of the Australian Electricity Market

Originally Posted by GraemeCook

I think we will learn to recharge during business appointments and lunch breaks, etc, and then wonder why we ever worried about such details.

Agreed Graeme, and charging times will come now very soon: as soon as next year there will be new chemistries that will take about 10 minutes, IIRC.

Forget the chemistry, to recharge a 60 kWh battery in 10 minutes would require a charger capable of delivering 360kW.

If the charge station has six chargers then the cables to the station have to handle 2.16MW and if it is a 230v mains that amounts to approx 9400 amps.

I can't see it in the conceivable future becoming commonplace as the existing grid can't handle that sort of load increase.

I should never trust my memory for stats: here it's saying the LMFP chemistry is 18 minutes fast charge (not sure to what %). So while the battery may be capable of that, as Bohdan says, the infrastructure has to be able to deliver too.

Originally Posted by GraemeCook

It is also beyond the range of most ICE cars, too, but we are used to pumping petrol in five minutes. There used to be four times as many servos as there now are, but we have adapted and still cope.

I have two vehicles, my farm ute (diesel) and my Golf that I bought because my ute won't go in Canberra carparks. Both will do 600km on a tank without effort, both will fill up in a couple of minutes, and I can't remember the last time I wait to wait for a pump. There may be fewer servos, but I'm guessing the number of pumps has probably increased - mom and pop single pump stations replaced by >10pump gas stations. The same applies to grocery stores!

Originally Posted by GraemeCook

It can be as short as 20 minutes to recharge an electric car with an untrafast charger. I think we will learn to recharge during business appointments and lunch breaks, etc, and then wonder why we ever worried about such details.

Assuming that every carparking space has a charger, then yes I agree. On the other hand, if you have 30minutes for lunch, and have to get to your car, drive to a charger (hoping it's available!), charge, pay and get back to the office, maybe it's not as easy as it sounds. Worse still when the b*stard at the charger is in a meeting, or having lunch, and ties the charger up for an hour!

Don't get me wrong, it will happen. But we are glossing over the problems, because they're not yet problems (and because early adopters are always very keen to extol the positives and play down the negatives!).

Most people will want to recharge at home, overnight. Solar power is no good for that. The fast charger systems may be able to recharge the vehicle quickly, but will the grid survive? If you look at a city service station and see how many cars go through, then slow that down to 10 minutes per car and total up the power draw for however many cars are charging at the same time, I don't think it will work!

The sensible approach is that every parking spot, whether private or public, has a trickle charger. Most people will never need anything more than that, as long as they plug in every time. Fast chargers should only be required on freeways (and other long distance routes).

Originally Posted by Bohdan

Forget the chemistry, to recharge a 60 kWh battery in 10 minutes would require a charger capable of delivering 360kW.

If the charge station has six chargers then the cables to the station have to handle 2.16MW and if it is a 230v mains that amounts to approx 9400 amps.

I can't see it in the conceivable future becoming commonplace as the existing grid can't handle that sort of load increase.

Exactly. Just thinking about a major fuel station on a major highway; six chargers would not be anywhere near enough for the number of vehicles needing to recharge. Try 12 to 15 chargers and you are looking at 5MW. There's a hell of a lot of infrastructure needed before running EV's on the highways becomes mainstream in Australia.

Some information for the three levels of charging that are generally (but not plentifully) available in Australia. The third level is the so-called fast charging and ultra fast charging which can be anything from 50KW/hr to 350KW/hr and will require a three phase source converted to DC.

EV Charging explained: Home and public charging, power levels and plugs (whichcar.com.au)

Regards
Paul

Originally Posted by Bushmiller

Some information for the three levels of charging that are generally (but not plentifully) available in Australia. The third level is the so-called fast charging and ultra fast charging which can be anything from 50KW/hr to 350KW/hr and will require a three phase source converted to DC.

EV Charging explained: Home and public charging, power levels and plugs (whichcar.com.au)

Regards
Paul

An interesting read, especially the included link to "how long do batteries last". If, as stated in that article, you shouldn't charge to more than 80%, or discharge to less than 10%, and the slowest rate of charging is best for battery life, how does this impact range? Are the manufacturers quoted ranges based on 100% to 0%, or 80% to 10%? And just how quickly does ultra-fast DC charging degrade batteries?

Originally Posted by Warb

An interesting read, especially the included link to "how long do batteries last". If, as stated in that article, you shouldn't charge to more than 80%, or discharge to less than 10%, and the slowest rate of charging is best for battery life, how does this impact range? Are the manufacturers quoted ranges based on 100% to 0%, or 80% to 10%? And just how quickly does ultra-fast DC charging degrade batteries?

Those numbers are the same for all Li-Ion batteries (phones, tools etc). and they are built into the batteries to happen automatically. With my phone I try to recharge when it falls below 30%. When it says it's 100% it is referring to "usable" capacity, the stated range should be accurate unless they are telling porkies.

If you exclusively fast charge any battery it will not yield as many cycles as trickle charging, so again referring to my phone, I only fast charge it when I need juice quickly, which is not often. Apart from anything else it keeps the battery cooler during charging. Extrapolating that out to vehicles, fast charging should be reserved for road trips where possible, and always trickle charge when time is on your side.

Fast charge and discharge, and the resultant heat is to be avoided for any Li-Ion battery. This is yet another reason why other chemistries and solid state batteries are being pursued.

Originally Posted by FenceFurniture

Those numbers are the same for all Li-Ion batteries (phones, tools etc). and they are built into the batteries to happen automatically. With my phone I try to recharge when it falls below 30%. When it says it's 100% it is referring to "usable" capacity, the stated range should be accurate unless they are telling porkies.

I understand the adjustment for battery degradation, I was more thinking about the fact that using an EV to it full quoted range (i.e. charging to 100% and then driving until "flat") is detrimental to its battery life. So for maximum battery life you need to subtract 30% from the stated range, to allow for 10% minimum charge and the 20% "avoid charging above 80%" advice?

Do EV's manage their charging to stop at 80%? I know my iPhone (according to the marketing) manages its charging to only charge the last 20% just before it thinks I'll need it, based on my historical usage.

Originally Posted by Warb

Do EV's manage their charging to stop at 80%? I know my iPhone (according to the marketing) manages its charging to only charge the last 20% just before it thinks I'll need it, based on my historical usage.

AFAIK, and I'll stand corrected, all Li-Ion batteries only ever charge to 80%, but show that they are 100% charged, which I regard as the "usable" charge. So for you phone I suspect it's only charging to actual 60% mostly, but adding on the last 20% to go to 80% when it thinks you'll need it.

So the usable range is 10-80%, and I believe that that 70% is displayed as 100% of usable sparks.

Originally Posted by FenceFurniture

AFAIK, and I'll stand corrected, all Li-Ion batteries only ever charge to 80%, but show that they are 100% charged, which I regard as the "usable" charge. So for you phone I suspect it's only charging to actual 60% mostly, but adding on the last 20% to go to 80% when it thinks you'll need it.

So the usable range is 10-80%, and I believe that that 70% is displayed as 100% of usable sparks.

So, when the iPhone tells me (in the battery health section) that maximum capacity is "98% of new", that's 98% of the 80% that it originally told me was 100%? Oh what a tangled web......

I think so.

Originally Posted by Warb

So, when the iPhone tells me (in the battery health section) that maximum capacity is "98% of new", that's 98% of the 80% that it originally told me was 100%? Oh what a tangled web......

They have to do it that way really. Imagine if they used the actual numbers:
"Why will my phone not charge above 80%?"
"Why does my phone keep turning itself off when there is still 10% of battery left?"

Rinse and repeat over 100s of millions of users.

Originally Posted by FenceFurniture

They have to do it that way really. Imagine if they used the actual numbers:
"Why will my phone not charge above 80%?"
"Why does my phone keep turning itself off when there is still 10% of battery left?"

Rinse and repeat over 100s of millions of users.

I agree, if that's what they're doing. But if it is what they're doing, why bother also doing the "stop charging at 80% until the last minute" thing on the iPhone? And why does the EV battery link tell us to avoid charging above 80%? If the safety limit (for want of a better phrase) is 80% of "real", why further reduce that by another 20%? Is the suggestion that charging above 60%odd "real" degrades battery life?