reduced charging current

[bakmigoreng]

Good Morning everybody,
I am new here, my name is Werner. I am from Germany, so forgive me wrong spellings please.
As all of you know, we are far behind in Germany with this model of car which was introduced just recently. I am going to buy one, for sure. I have my own power from a solar plant and I think of using that for the charging of the car while I am at home.
My question is, can the charging work all right if I reduce the current to 5 amps max ??????
I have not enough panels on the roof to provide the standard 10 Amps which are required for the charging on an ordinary socket at home. Extension is not possible, the roof is full.
The voltage and frequency are no point. It is the current I would not be able to provide. I belive the max I can provde would be 5 Amps which are 1,200 VA or 1,200 Watt (if no losses involved) We have 240 Volt, 50 Cy in Germany.

Do me a favour and do not get to sophisticated, my English might then not be sufficient.

Im fine if you tell me works yes / no

Thank you very much in advance.
Werner

 

[IgorTr]

Hi.

J1772 charger standard tell us, that mininum is 6A in analog selection mode.
https://code.google.com/p/open-evse/wiki/J1772Basics
I do not found any information about digital mode of communication....

So, if you use 120V-10А-50hz - this is it - 1.2 kW.
But...its more that 12 hours to charge. It will not work in real life.

 

[maby]

Hi.

J1772 charger standard tell us, that mininum is 6A in analog selection mode.
https://code.google.com/p/open-evse/wiki/J1772Basics
I do not found any information about digital mode of communication....

So, if you use 120V-10А-50hz - this is it - 1.2 kW.
But...its more that 12 hours to charge. It will not work in real life.

That is interesting - but it describes the control signals coming from the charging point and going to the car - the charging point is advertising the maximum current it can source and the car is free to request anything up to that value. You would need to build or modify a charging socket to advertise the reduced current. As already stated, at 5A you will be increasing the charging time to inconvenient numbers - on a cloudy day, you could find that there is not enough power available to drive the charger at all.

 

[bakmigoreng]

so if I get it right, I can built some kind of a throttle, whatever that might be, into that line to the socket in question and I can limit the current down to say 5 amps and this would work. That control box hanging in the cable would not quit the job by saying "no sufficient current available"
Shure it would take then far more time to get the batteries charged to the maximum. But I´m not using the car every day, so it does not bother really. And at the end, I have a gasoline engine which would bring be from A to B on a cloudy day. This is what makes the concept of this car sooooooo very interesting to me.

Thank you very much to this point for the reply and im looking forward to more.

Brgds
Werner

It just pops ino my mind. The car has a secon connection, assuming this is 120V DC connection. To regulate a DC power is not that difficult. How if I transform 240 AC to 120 DC and I block the current ?? Actually this is for a scilled elecronic freak

 

[bakmigoreng]

so if I get it right, I can built some kind of a throttle, whatever that might be, into that line to the socket in question and I can limit the current down to say 5 amps and this would work. That control box hanging in the cable would not quit the job by saying "no sufficient current available"
Shure it would take then far more time to get the batteries charged to the maximum. But I´m not using the car every day, so it does not bother really. And at the end, I have a gasoline engine which would bring be from A to B on a cloudy day. This is what makes the concept of this car sooooooo very interesting to me.

Thank you very much to this point for the reply and im looking forward to more.

Brgds
Werner

It just pops ino my mind. The car has a secon connection, assuming this is 120V DC connection. To regulate a DC power is not that difficult. How if I transform 240 AC to 120 DC and I block the current ?? Actually this is for a scilled elecronic freak

why on earth is this thread blocked now ??????????????????????????

 

[maby]

so if I get it right, I can built some kind of a throttle, whatever that might be, into that line to the socket in question and I can limit the current down to say 5 amps and this would work. That control box hanging in the cable would not quit the job by saying "no sufficient current available"
Shure it would take then far more time to get the batteries charged to the maximum. But I´m not using the car every day, so it does not bother really. And at the end, I have a gasoline engine which would bring be from A to B on a cloudy day. This is what makes the concept of this car sooooooo very interesting to me.

Thank you very much to this point for the reply and im looking forward to more.
In
Brgds
Werner

It just pops ino my mind. The car has a secon connection, assuming this is 120V DC connection. To regulate a DC power is not that difficult. How if I transform 240 AC to 120 DC and I block the current ?? Actually this is for a scilled elecronic freak

why on earth is this thread blocked now ??????????????????????????

is it blocked? Seems to be working to me. ..

My interpretation of that specification is that the charging point advertises its maximum current through the duty cycle of a square wave that it pushes down one of the wires connecting to the car so, yes, I think you could intercept the signal and replace it. Obviously this could invalidate warranties on the car or charging point and could put the user in danger if done incorrectly.

 

[bakmigoreng]

Soory, I was looking at that black dot incorrectly. Left to the thread on the forum overview "technical discussion is a black dot. And down in the list where the symbols are explained is written "blocked" but that was wrong. The wording right side to that shows "unread post" and this ist wat t means. Again, sorry.

Coming back to the point of the reduced charging, I have to read your input again and maybe I have to translate it. I do not really understand it. But one thing yes, I agree with you, is the guarante issue. Let me think about it.

Still I am thinking of regulating the DC input via that second port. This must be direct link to those batteries, right ? Does nobody have a wiring diagram available ??

Good night, its getting late.
Werner

 

[maby]

Soory, I was looking at that black dot incorrectly. Left to the thread on the forum overview "technical discussion is a black dot. And down in the list where the symbols are explained is written "blocked" but that was wrong. The wording right side to that shows "unread post" and this ist wat t means. Again, sorry.

Coming back to the point of the reduced charging, I have to read your input again and maybe I have to translate it. I do not really understand it. But one thing yes, I agree with you, is the guarante issue. Let me think about it.

Still I am thinking of regulating the DC input via that second port. This must be direct link to those batteries, right ? Does nobody have a wiring diagram available ??

Good night, its getting late.
Werner

I think the question is how low you need to take the charging current. The specification mentioned above seems to describe how to make the car limit its consumption to 6A but that is the lower limit. Any reasonably experienced electronic engineer should be able to modify a cable to adjust the charging current based on that document.

 

[IgorTr]

There is no need to hack or intercept communication. Just build (buy) the wall station which advertise, that maximum allowed current is 6A.
Onborad chager will do the rest.
It could be 120V * 6A = 0.7 kWt limit, or 240 V *6A = 1.4 kW limit.

DC socket is not a 120V. It something around 300V-DC. In simplifed term - its a battery terminals.
Its a very good point, that your solar panels are also DC. It could be very efficient to connect them directly to car
( and in series to get ~300 V-DC), BUT... there is a digital link between fast chaging station and car.
It does not seems to be open standart( or avaliable somehow ).
Charing will not work until successfull negotiation between charger ( now it not onboard but external one) and battery monitoring computer on board.

 

[maby]

There is no need to hack or intercept communication. Just build (buy) the wall station which advertise, that maximum allowed current is 6A.
Onborad chager will do the rest.
It could be 120V * 6A = 0.7 kWt limit, or 240 V *6A = 1.4 kW limit.

DC socket is not a 120V. It something around 300V-DC. In simplifed term - its a battery terminals.
Its a very good point, that your solar panels are also DC. It could be very efficient to connect them directly to car
( and in series to get ~300 V-DC), BUT... there is a digital link between fast chaging station and car.
It does not seems to be open standart( or avaliable somehow ).
Charing will not work until successfull negotiation between charger ( now it not onboard but external one) and battery monitoring computer on board.

But the fact remains that the OP is seeking to get the current draw down to 5A and the specification seems to indicate that 6A is the lowest option supported.

 

[IgorTr]

Not a problem to get 5A because its possible to convert AC 240V to AC 120V without losses. Just a simple transformer can do this.
10A at 120V will be 5A at 240V
6A at 120V will be 3A at 240V

 

[maby]

Not a problem to get 5A because its possible to convert AC 240V to AC 120V without losses. Just a simple transformer can do this.
10A at 120V will be 5A at 240V
6A at 120V will be 3A at 240V

Quite true - but 10A at 120V and 5A at 240V are both 1.2KW and the OP was looking for a way to keep the drain within the capabilities of his PV panels. if I understood him correctly, he needs to keep the charging load at 5A, 240V or lower.

 

[bakmigoreng]

Correct. The cable I found is for adjustable current. "EVSELECT J1772 EVSE Variabel Amp" with 1 Amps stepsfrom 6 to 16 Amps
The minimum however is 6 Amps
Mitsubishi tell me, the minimum I can go to is 5 Amps. But they do not supply such cable.
Does anybody built a cable for 5 Amps ??

 

[maby]

Correct. The cable I found is for adjustable current. "EVSELECT J1772 EVSE Variabel Amp" with 1 Amps stepsfrom 6 to 16 Amps
The minimum however is 6 Amps
Mitsubishi tell me, the minimum I can go to is 5 Amps. But they do not supply such cable.
Does anybody built a cable for 5 Amps ??

I suspect that you are going to have to get one made up - or modify the one you have. Any moderately competent electronic engineer could do it with the information in that document.