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As someone who cannot us rapids anyway, I am slightly nervous about the notion that a public rapid charger which may not be too well maintained would be in control of what happens to my battery. I thought that all the tapering of charge rates and power levels was controlled by the car to protect the battery. Is that wrong?
No, that's about right.

When using the OBC with AC the conversion and charging is fully controlled by the OBC. However the charge point or granny charger communicates with the OBC to ensure the cable is properly connected and to tell the OBC what the maximum current is that it can pull - obviously drawing 30A from a 13A or 16A supply will not end well.

With a rapid DC charger the external unit does the AC-DC conversion and has the power electronics to regulate the DC output to the car. But as with the AC case the car and charger talk to each other and it is the car that tells the charger what power it can accept. So a 150kW charger will only put 50 max into a 50kW capable car. As the car battery gets full, or is cold, etc, the car will tell the charger to push less current.

So yes, the car is in control, unless the DC charger goes mad. In that case I imagine the car's BMS will take evasive action, perhaps opening the main contactor.
 

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Power quality.

To add in the additional features to make the supply free of transients takes up a lot of physical bulk in the form of large capacitors and inductors, which is space and weight a regular car can't afford.

Renault does it by using its particular motor design to double up as the inductors. Not possible with any other current EV.

That's assuming the voltages are compatible in the first place, which will be even more bulk mass and cost if not.

A home charger would still be 7 kW or so, just DC to the car.
Perhaps you missed the point that EVs already charge the battery during regen?
 

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I see the point @donald is making that long term (at least 5 years) AC charging might disappear or be a cost option.

It is far harder and expensive to do V2G with AC, so long term homes could have low power DC charging due to V2G requirements. The units are already getting cheaper and smaller as we see with the current trial.
The grid is AC, the battery DC. Not beyond the ingenuity of man to make it work.
 

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The grid is AC, the battery DC. Not beyond the ingenuity of man to make it work.
Not sure I understand your point. AC bidirectional already has a standard (ISO15118) and there are trials, some including modified Zoe.

My point was that (in addition to OBC) it requires the car to have an inverter to convert DC from battery to AC, which adds more complexity and cost! I guess a side benefit is that they may be able to include a 240V outlet like on the Sion, so you can offer a charge to a fellow EV driver or power stuff.
 

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Not sure I understand your point. AC bidirectional already has a standard (ISO15118) and there are trials, some including modified Zoe.

My point was that (in addition to OBC) it requires the car to have an inverter to convert DC from battery to AC, which adds more complexity and cost! I guess a side benefit is that they may be able to include a 240V outlet like on the Sion, so you can offer a charge to a fellow EV driver or power stuff.
And it has a tow bar! What is the downside?

I think my point is that the car already has hefty DC to AC, and AC to DC converters. In principle you just have to make the grid look like an AC motor/generator.
 

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Does it matter if the onboard charger can only convert at a rate of 11 or 7 (or even 3.6) kW - if you plug in when you get home in the evening, you will have a fully charged battery by the next morning.
There are two 'modes' of charging - destination charging when the car is charging while you are doing something else, and en-route charging when you are waiting for the car to charge so you can get on with your journey.

For destination charging, providing you can get enough charge for your next journey while you are at the destination, the actual charging rate does not matter.

For en-route charging, you would like to charge as quickly as possible so that you can be on your way, so the 'Rapid' chargers that feed DC direct to your battery are the ones to go for.
There are two 'modes' of charging - destination charging when the car is charging while you are doing something else, and en-route charging when you are waiting for the car to charge so you can get on with your journey.

For destination charging, providing you can get enough charge for your next journey while you are at the destination, the actual charging rate does not matter.

For en-route charging, you would like to charge as quickly as possible so that you can be on your way, so the 'Rapid' chargers that feed DC direct to your battery are the ones to go for.
 

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Perhaps you missed the point that EVs already charge the battery during regen?
Perhaps you missed the point that the car is not connected to the mains during regen.

How do electrical spikes get from an EV to the mains when it's not plugged in?

You can't plug any old shit into the mains, it has to meet certain requirements not to put interference into the mains supply. Haven't you heard of all the trouble Zoes have caused some people?
 

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In principle you just have to make the grid look like an AC motor/generator.
As a Chartered Engineer working in the field of automotive HV systems, I am not that interested in helping people understand basic fundamentals of the engineering required if they don't want to learn and think buying a bag of cheap Chinese electrical parts, putting them in a box and shaking it around is all that is needed.

Why don't you tell me how to build a switched mode kW class power converter which outputs zero harmonic content? Maybe I am missing something that 20 years in the field hasn't taught me that you've figured out yourself in your armchair.
 

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As a Chartered Engineer working in the field of automotive HV systems, I am not that interested in helping people understand basic fundamentals of the engineering required if they don't want to learn and think buying a bag of cheap Chinese electrical parts, putting them in a box and shaking it around is all that is needed.

Why don't you tell me how to build a switched mode kW class power converter which outputs zero harmonic content? Maybe I am missing something that 20 years in the field hasn't taught me that you've figured out yourself in your armchair.
No need to be like that. There is a difference between "in principle" and "perfected". I do have a very quiet four quadrant 1 kW servo controller for a precision rolling mill that I made 20 yrs. ago sitting in a cupboard somewhere, so I did get out of the armchair sometimes. I did wonder about you when you implied the motor inductors used in a Zoe charger were just there for transient suppression, rather than energy storage , but I let it pass:)
 

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No need to be like that. There is a difference between "in principle" and "perfected". I do have a very quiet four quadrant 1 kW servo controller for a precision rolling mill that I made 20 yrs. ago sitting in a cupboard somewhere, so I did get out of the armchair sometimes. I did wonder about you when you implied the motor inductors used in a Zoe charger were just there for transient suppression, rather than energy storage , but I let it pass:)
They are the inductors to the switched mode circuit, AFAIU.
 

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Yes, there are various strategies to help, which is all the more surprising that Zoe is so noisy when it charges, even at just 7kW!
 

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Yes, there are various strategies to help, which is all the more surprising that Zoe is so noisy when it charges, even at just 7kW!
Try not to lapse into logical fallacy ever again (" I am too qualified to talk to the likes of you") or I might no longer stay a fan..
 

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Yes, did certainly register before I made that post.

I have every confidence that Indra will manage quality of supply, installation, maintenance and possibly operation over the period of a TRIAL.

Not the same as mass market IMHO.

Any views from Indra themselves on what would be required long term?

Just conscious that at 400V (800V for some cars on the way) we have crossed over some basic physiological safety barriers. Certainly with Public DC charging, we expect that a level of maintenance is carried out by competent persons.
Sorry. Missed this thread.

So safety for DC at home (with the Indra V2G)...

-We are using the very mature CHAdeMO standard.

-High quality certified cables and connectors.

-No voltage in the cable until all checks are complete.

-Cable locked into position while charging.

-Insulation and isolation check of the cable during every charging initiation.

-Constant checking for DC leakage while in operation.

-Higher dielectric rating than AC chargers.

-Constant checking of circuit resistance while in operation.

-Dual galvanic isolation in the power electronics - we go from ac-dc-ac-dc when charging and dc-ac-dc-ac while discharging (cars generally have a single isolation barrier). This means there is no meaningful current path from DC to chassis ground or Earth. The only way you could get electrocuted by the charger is to somehow touch HV+ and HV- while the CHAdeMO protocol is satisfied everything is OK, even then the resistance check above kicks in.

-Much more monitoring within the charging point (which includes the power stage) which is web connected and monitored allowing us to see issues and trends.

- Charger itself can isolate the DC and or AC supply in/out of the charger if it senses a fault.

-Logging available do help learning should something go wrong.

-Insulation, Fire retardant, impact and mechanical shock rating of the enclosure hugely exceed regs.

-Emergency stop button just in case.

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FWIW, i think we'll see DC charging become the norm (at home/on route/autonomous hub) with on board chargers reduced to granny lead spec to keep cost down.



Sent from my SM-N950F using Tapatalk
 

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Well that's definitive, from the inside.

Donald, I have to admit you are probably spot on with your observations and predictions.

I have one niggle, and won't get started on this tonight but it's to do with the protocol.😗
 

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Well that's definitive, from the inside.

Donald, I have to admit you are probably spot on with your observations and predictions.

I have one niggle, and won't get started on this tonight but it's to do with the protocol.😗
You've redeemed my earlier "You're being dumb and argumentative" comment by now applying some progressive thinking to the matter. (y)
 
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