Frequent 50KW DC charging and the Model3

[Roy W.]

Why do you say 50 kW has a large heating impact? Sources for that information?

A Model 3 isn’t a Kona and it’s obviously not “pence” and a few “free Watts”.

All the problems with “Rapidgate” on the Nissan Leaf 40kWh and larger are caused by the battery heating effect.

I ordered a 40kWh Leaf in early 2018. Because the Rapidgate story had just broken, I arranged for an extended test drive, in order to use a rapid charger and see the effects. I was only charging on a max 50kW CHAdeMO charger, so getting rates up to low 40s.

While charging the battery temperature gauge on the Leaf was going up. During the second charge the battery was so hot the car was throttling the charge rate to 17kW. I cancelled the order for the Leaf.

I charge exclusively at home, and that adds about £20 a month to my electricity bill.

As you correctly say, a Model 3 isn’t a Kona, or a Leaf. But they are all based on similar technology. I’m not saying I’m correct, and I’m only trying to help.

It’s your battery - you do what you like with it.

 

[MaDProFF]

My car was preset at 90% on delivery. I wish they had a percentage on charge on the battery gauge

 

[cezdoc]

Even supercharger rapidly drops off charge rate as SoC increases.

20% - 100% - Come 30 minutes in, down to 50kW. Final 30 minutes was at 7kW or less.

PS looks like right hand Y axis legend is wrong

This is true but if the horizontal axis was battery state of charge (%) instead of time I expect the battery was at ~85% before the charge rate dropped below 50 kW, so a big chunk of time was spent getting in the last 15%. This is why a max charge default/limit of 80% has recently been brought in at busier UK Superchargers.

Standard rapid chargers will be 50kW max (as the OP says ~20-50 in real life) so Superchargers still win up until very high states of charge. I have an etiquette dilemma when using a Supercharger on the edge of a charging desert - if I'm spending time in an area where I can't guarantee I'll be able to charge then it's faster to "fill up" at a Supercharger even though we're encouraged to move on as soon as we're able to.

 

[ACarneiro]

T


I find that frustrating. I’m getting a 22KW charger installed at home and will only be able to charge at 11KW. A friend of mine has a Zoe and will be able to use MY charger to charge at 22KW

Are you one of the lucky ones with three phase power at home as well?

 

[ivangr]

All the problems with “Rapidgate” on the Nissan Leaf 40kWh and larger are caused by the battery heating effect.

I ordered a 40kWh Leaf in early 2018. Because the Rapidgate story had just broken, I arranged for an extended test drive, in order to use a rapid charger and see the effects. I was only charging on a max 50kW CHAdeMO charger, so getting rates up to low 40s.

While charging the battery temperature gauge on the Leaf was going up. During the second charge the battery was so hot the car was throttling the charge rate to 17kW. I cancelled the order for the Leaf.

I charge exclusively at home, and that adds about £20 a month to my electricity bill.

As you correctly say, a Model 3 isn’t a Kona, or a Leaf. But they are all based on similar technology. I’m not saying I’m correct, and I’m only trying to help.

It’s your battery - you do what you like with it.

They are not based on similar technology and they are not the same.

As I understand it the Leaf does not have liquid cooling. The Model 3 has a newer and more advanced liquid cooling setup than the Model S even.

 

[Roy W.]

They are not based on similar technology and they are not the same.

As I understand it the Leaf does not have liquid cooling. The Model 3 has a newer and more advanced liquid cooling setup than the Model S even.

My point was that you was saying that 50kW charging did not have a heating effect on the battery. If that’s the case, why have a cooling system?

I bow to your more advanced knowledge.

 

[WannabeOwner]

I typically pop out during my lunch break and stick it on a 50KW (21-48KW actual speed) charger and charge back up to 90%.

Is this a bad idea? Will it damage the battery in the long run?

Model-S/X have a counter for the number of Rapid DC charges. I have no idea if 50kW is within the threshold of "Rapid" ... maybe the counter is "All DC charges" and maybe the Counter exists on Model-3 too.

After the Counter hits some significant number the rate at which the car will DC charge is reduced, to look after the battery long term. The reduction is not much, and increases slowly over a large number of additional DC charges. I have no idea if the throttling that then occurs actually reduced 50KW charging, or only 100+kW charging ... but clearly if you get to that point and your occasional 100+kW charging becomes "throttled", and you have to wait longer at Raipd Chargers as a consequence, it would be worth being aware of

So you might find that happens to you, if you routinely charge on DC rather than AC.

90% SOC is fine, so no need to worry about that part, except that 50kW charging will taper as it gets over 80% or so, so if you are paying by "time" rather than "kWh" that might increase the cost.

I’m getting a 22KW charger installed at home and will only be able to charge at 11KW.

I'm sure there are people who come-home-and-go-back-out often enough to need 22kW but it is rare. 11kW is 44 MPH charging on Model-3, so 300 mile added in under 7 hours - and have to both come home empty, and charge to 100%, to be needing that much juice.

The lower A/C charging rate is a cost saving measure, so unless significant proportion of owners need it then no sense adding it as standard, and Tesla is not offering much as "options" any more, to streamline production. Over the years higher kW A/C charging has been available as an option on Model-S, but I figure that if demand was high it would have become standard.

 

[curmudgeon]

e


good reply. I’ve rationalised things a bit. I would say most of my charging on 50kw’s is 21-34 kw. So, I think the “heat” impact should be minimal. It’s not exactly supercharger rates.

And yes, in Scotland it’s free and we pay higher taxes than the rest of the country to afford stuff like this so I’m keen to get the full benefit out of it.

Same in Northern Ireland, all public chargers are free. Its actually illegal to charge a fee for EV charging. But its a bad policy that fails in its objective of making long-distance EV travel possible because it encourages freeloaders to fill their boots with free energy close to home hence preventing drivers with genuine need from reaching their destination.

Free rapid charging is a just a bad idea. We are desperate here for the law to change and all the free charging stations to introduce fees but while there is no assembly we cannot get a change in the law.

If you must occupy a free rapid charger at lunch time to save £3.50 on the leccy bill then at least leave a phone number on the dash so that those with greater need can ask you to move.

 

[Artiste]

Are you one of the lucky ones with three phase power at home as well?

Yes - I couldn’t believe it when I checked my supply and found three big, fat 100A fuses

 

[ivangr]

Same in Northern Ireland, all public chargers are free. Its actually illegal to charge a fee for EV charging. But its a bad policy that fails in its objective of making long-distance EV travel possible because it encourages freeloaders to fill their boots with free energy close to home hence preventing drivers with genuine need from reaching their destination.

Free rapid charging is a just a bad idea. We are desperate here for the law to change and all the free charging stations to introduce fees but while there is no assembly we cannot get a change in the law.

If you must occupy a free rapid charger at lunch time to save £3.50 on the leccy bill then at least leave a phone number on the dash so that those with greater need can ask you to move.

I've not prevented anyone from getting the charge they need. We are reasonably well stocked where I live, there are lots of rapid chargers around my town. I would think the issue really is that you need more charging facilities built or you need to limit time at the chargers. I'm happy with a limit on time. I mean Tesla does this when there is high demand on the Superchargers - the Edinburgh one will limit you to 80% charge if more cars are inbound.

A model S drove up the other day looking for a Chademo and I jumped out and waved him in to get my space.
Unfortunately (fortunately) free charging is needed to accelerate uptake - good for us all. I don't see an issue with all EV chargers benefiting from it. It will help us make the decision to buy a second EV (where our other car is currently a Hybrid).

 

[Artiste]

[QUOTE="WannabeOwner, post: 4091483, member: 40637"I'm sure there are people who come-home-and-go-back-out often enough to need 22kW but it is rare. 11kW is 44 MPH charging on Model-3, so 300 mile added in under 7 hours - and have to both come home empty, and charge to 100%, to be needing that much juice.[/QUOTE]

No, I don’t need that much juice, but as the prices for the single phase and three phase Andersen chargers are virtually identical it makes no sense at all to go for the single phase.

 

[ivangr]

My point was that you was saying that 50kW charging did not have a heating effect on the battery. If that’s the case, why have a cooling system?

I bow to your more advanced knowledge.

OK I understand. Apologies. Not enough sleep and too grumpy in the morning. Thanks for your feedback.

 

[arg]

My point was that you was saying that 50kW charging did not have a heating effect on the battery. If that’s the case, why have a cooling system?

I think the real answer is a combination of the different points already made in this thread. 50kW charging (which in fact is usually 45kW or less on most chargers branded "50kW") has proportionately less heating effect on Tesla batteries than Leaf batteries simply because the Tesla battery is larger than the Leaf battery and so the heating effect is spread over a greater mass of reactive material in the battery; then on top of that the Telsa battery has a cooling system, so any heat that is generated is more readily removed. With two extra safety factors, it is reasonable to conclude that 50kW charging of a Tesla is less stressful than 50kW charging of a Leaf.

A further datapoint is that Model 3 batteries hit their thermal limit after a short period of charging at ~200kW, while 40kWh Leaf batteries hit their thermal limit after a moderate period of charging at 50kW. In both cases, the cars charge at full power until they hit the limits considered by their respective designers to be acceptable for long-term health. So you might say that charging a Model3 at max supercharger rate and a Leaf40 at 50kW is comparably bad for the battery - both charge until their battery hits the upper limit of acceptable temperature and then continue at a lower rate. You might speculate that Tesla are less conservative than Nissan in determining "acceptable", but probably not by a wide margin as both have warranties to honour.

Another way of looking at it is that charging a Model 3 at 50kW is significantly less stressful than at full supercharger rates, and since full supercharger rates don't appear to cause massive problems then 50kW is likely to be even less of a risk.

However, there is the (unconfirmed) issue that Tesla may lump all DC charging together in counting towards charge-rate limiting for "older" batteries, ignoring the fact that some of it may have been less stressful than Supercharging.

 

[webbah]

Yes - I couldn’t believe it when I checked my supply and found three big, fat 100A fuses

I have 3 phases and my car charges with all 3 (3*16A=48A) on a type 2.

 

[Roy W.]

OK I understand. Apologies. Not enough sleep and too grumpy in the morning. Thanks for your feedback.

No worries @ivangr, we've all been there

 

[ivangr]

I've not prevented anyone from getting the charge they need. We are reasonably well stocked where I live, there are lots of rapid chargers around my town. I would think the issue really is that you need more charging facilities built or you need to limit time at the chargers. I'm happy with a limit on time. I mean Tesla does this when there is high demand on the Superchargers - the Edinburgh one will limit you to 80% charge if more cars are inbound.

A model S drove up the other day looking for a Chademo and I jumped out and waved him in to get my space.
Unfortunately (fortunately) free charging is needed to accelerate uptake - good for us all. I don't see an issue with all EV chargers benefiting from it. It will help us make the decision to buy a second EV (where our other car is currently a Hybrid).

Here is a pic of my local charging bays at 16:45. Really no contention. I mostly charge at Park
and Rides around Edinburgh (which seem to be setup for people to leave their cars on AC charge for the day).

 

[ACarneiro]

That’s pretty amazing

 

[ittah]

The model 3 charging at DC 50KW does start making banging noises at around 10min - like someone hitting the underneath of floor with a hammer. Apparently thermal expansion of the metal shell of the battery, similar to pouring hot water directly on a kitchen sink. So DC charging would have some effect if it’s creating that much heat.

 

[NewbieT]

My car was preset at 90% on delivery. I wish they had a percentage on charge on the battery gauge

Perhaps this is so that you don’t always charge to exactly the same point. Sometimes 87%, 92% etc to avoid a memory effect?

 

[ianto999]

Here is a pic of my local charging bays at 16:45. Really no contention. I mostly charge at Park
and Rides around Edinburgh (which seem to be setup for people to leave their cars on AC charge for the day).

Which park.and ride is that one?