2 EVs Charging Solution

goz83

So I now have 2 24kw Leafs. One is 3.3 and the other is 6.6 OBC.

I currently have a 32A Tethered Rolec EVSE with the 13A socket. There will be times I want to have both cars charged overnight, so what can I do without spending a fortune?

I could plug in the Granny charger and permanently mount it to the wall, but I am not 100% happy with that idea.

I could sell the second granny charger for around 4-500 and buy a second EVSE, but then I have another installation to pay for and not sure if I can actually add another EVSE.

Maybe I can just get a plug in EVSE that I plug into a standard socket and charge at granny speed. I would be more open to this than mounting a granny cable on the wall....and it would probably cost a bit less too than the price I would get for a granny cable if I sold one.

Is there a method I could add another cable to the current EVSE? I am thinking yes, but I shouldn't even consider this.

unkel

Is the 13A socket waterproof? With the granny cable plugged in? If the answer is yes, I'd leave the granny cable plugged in permanently. Secure it with a lock. Are your cables long enough that they can reach both cars?

You probably need a heavier than 40A RCBO too? And can your EVSE handle 10kW charging?

goz83

unkel wrote: »

Is the 13A socket waterproof? With the granny cable plugged in?

It's part of the EVSE, so I would say yes. Otherwise they wouldn't have rated the unit as waterproof.

unkel wrote: »

If the answer is yes, I'd leave the granny cable plugged in permanently. Secure it with a lock.

If doing this, I would have it mounted in a way that a lock wouldn't be necessary.

unkel wrote: »

Are your cables long enough that they can reach both cars?

Yes, both the tethered cable and the granny cable would reach either car.

unkel wrote: »

You probably need a heavier than 40A RCBO too?

Not sure. That's where my knowledge fails me.

unkel wrote: »

And can your EVSE handle 10kW charging?

I assume you mean if I attached another cable (not the granny cable). Again, I don't know if it would. I assume it wouldn't. If I had another cable wired into the EVSE, I would have the car timers set so that only one would charge at a time.

unkel

goz83 wrote:

I assume you mean if I attached another cable (not the granny cable). Again, I don't know if it would. I assume it wouldn't. If I had another cable wired into the EVSE, I would have the car timers set so that only one would charge at a time.

No I meant granny cable in the EVSE and charging both cars at the same time! I'd email the manufacturer and ask them. It could very well be possible! You'd need a 48A RCBO though if you want to charge at 32A + 13A. It would be very handy for you if you could. Almost zero costs too

KCross

You need to ask Rolec if there is load sharing between the 3-pin and the type-2 socket.

If there isn't you might have a problem. If you try to charge the 6.6kW (30A) on the Type 2 and the 3.3kW on the granny cable (10A) at the same time, that is right on the limit of the 40A RCBO on both sides (distribution board and EVSE).

You would need to either swap them so that the 6.6kW is charged on the granny charger (10A) and the 3.3kW (15A) is charged on the Type 2. It would mean making sure you don't mix up the plugs any night or you could end up waking up to two uncharged cars!

I don't think the timers in the cars will help as the granny charger is almost certainly going to overlap with the 6.6kW at some stage of the night.


Slightly left field suggestion.... You did say you didn't want to spend money but I think you should have an eye on the future here. Since you have already decided to be a 2 house EV it is likely that in the long term you could have two 7kW cars parked out front. The best solution I've seen so far is the Tesla Wall Connector one where you have two EVSE's load sharing. You set the max load for the connection and it shares it across the 2 cars.
https://www.tesla.com/en_IE/support/load-sharing-tesla-wall-connector

If you decide to go with a 2nd EVSE you should consider the two Tesla Wall Connector route. You could sell the granny cable and your existing EVSE to cover the two Tesla's!

KCross

A post here from cros13 which shows a pic of it installed:
http://www.boards.ie/vbulletin/showpost.php?p=102576324&postcount=8

A Tesla Wall Connector is €512 so they are not a ridiculous price considering the design and features it has.

goz83

KCross wrote: »

A post here from cros13 which shows a pic of it installed:
http://www.boards.ie/vbulletin/showpost.php?p=102576324&postcount=8

A Tesla Wall Connector is €512 so they are not a ridiculous price considering the design and features it has.

That's all great info, cheers. I will send an email off to rolec and see what they say. If I were to set the timers on the cars, I would leave a 20 minute gap to prevent any cross-over, but it would be cool if I didn't have to do that.

On the Tesla wall chargers. That's a real possibility, but I am just a bit confused about 1 aspect. Will it work for a Leaf? I would need a type 1 cable, yes?

unkel

goz83 wrote:

On the Tesla wall chargers. That's a real possibility, but I am just a bit confused about 1 aspect. Will it work for a Leaf? I would need a type 1 cable, yes?

It's just type 2 like every other non - tethered EVSE so yes, just use your type 2 to type 1 cables that came with your Leafs

I wonder how many 2 EV families there are I Ireland? Probably only a handful!

goz83

unkel wrote: »

It's just type 2 like every other non - tethered EVSE so yes, just use your type 2 to type 1 cables that came with your Leafs

I wonder how many 2 EV families there are I Ireland? Probably only a handful!

I would want it as a tethered type 1. Wouldn't want the hassle of moving cables in and out of the boots. I searched EV cables online just now and can't seem to fing a type 2 - Type 1. Must not be looking for the right thing.

KCross

goz83 wrote: »

That's all great info, cheers. I will send an email off to rolec and see what they say. If I were to set the timers on the cars, I would leave a 20 minute gap to prevent any cross-over, but it would be cool if I didn't have to do that.

How would a 20min gap work considering the granny charger could be 11hrs charging?

I can't see how the timers would solve it for you while staying inside the 9hr night rate.

goz83

KCross wrote: »

How would a 20min gap work considering the granny charger could be 11hrs charging?

I can't see how the timers would solve it for you while staying inside the 9hr night rate.

It would be far from ideal, that's for sure, but we rarely have the battery below 50%, so the 6.6 would be charged pretty quickly and the other one would take the rest of the charging time.

I have a second outdoor socket I could use, but it's awkward to get at, because I have to walk up on the pond wall to get to it.

I may well be jumping too soon here. We may do just fine with the one EVSE. So will give it a couple of weeks before making any decision. I like my Rolec

oppenheimer1

It's also worth thinking about the size of the main fuse with most being 63amps. The two EVs charging at 9.9kwh and the electric immersion or other high demand appliance comes on could get you uncomfortably close to supply limit.

If you have an electric shower I presume it's already on a priority switch?

unkel

I think he has several electric showers (and a priority switch)

Unless you want to live a third world lifestyle, I'd recommend getting rid of all your electric showers and gave a powerful water pump installed instead. It's not expensive either but you do need a very large hot water cylinder and a powerful way to heat your water. Large array of Solar tubes and a powerful high efficiency gas boiler. Or just the gas boiler if you don't want to go the renewable way...

goz83

oppenheimer1 wrote: »

It's also worth thinking about the size of the main fuse with most being 63amps. The two EVs charging at 9.9kwh and the electric immersion or other high demand appliance comes on could get you uncomfortably close to supply limit.

If you have an electric shower I presume it's already on a priority switch?

Yeah, I believe it's a 63A main fuse. The EVs would only charge at night rate time. The dishwasher and washing machine would run after midnight. My PC would be in sleep mode. The modem stays on. The tv, digibox and playstation would be on standby and we might have a couple of LED lights left on. Also phones charging. That's all pretty typical.

Have electric shower on priority switch. Will be getting rid when I am in a position to install a proper pump shower....maybe with thermodynamic panel heating the water.

oppenheimer1

goz83 wrote: »

Yeah, I believe it's a 63A main fuse. The EVs would only charge at night rate time. The dishwasher and washing machine would run after midnight. My PC would be in sleep mode. The modem stays on. The tv, digibox and playstation would be on standby and we might have a couple of LED lights left on. Also phones charging. That's all pretty typical.

Have electric shower on priority switch. Will be getting rid when I am in a position to install a proper pump shower....maybe with thermodynamic panel heating the water.

With the 6.6kw leaf and the granny cable going you'd be pulling close to 40amps. With a kettle on you will have 10amps for the rest of your house. I'd say you'll need a bit of load management pushing the running of washing machine and dish washer much later into the night.

It can be done, just the members of the household will need to know that tea and toast can't be on together with the cars plugged in.

Btw the pumped shower of the tank is the business. Parents have it with a wood chip boiler and couldn't be happier with it.

goz83

Just as well I don't drink tea/coffee after midnight

reboot

Very interesting discussion, I guess we need to consider if the average household can deliver such high current drain for two EVs? I doubt if mine would.

ei9go

I think you can get your supply upgraded to 80 amp.

ELM327

If it were 2 3.3kW or 2 Granny Cable connected EV it would be fine.
Have you considered using the 3.3 cable on the 6.6 and getting a second 3.3 CP installed and using the 6.6 cable for the 3.3 car. That way the max current drawn would be 6.6kW for the two cars. The 3.3 car is limited by the OBC to 3.3kW, and the 6.6 car would be limited by the 3.3 cable to 3.3kW.

goz83

ei9go wrote: »

I think you can get your supply upgraded to 80 amp.

Will ask about that

ELM327 wrote: »

If it were 2 3.3kW or 2 Granny Cable connected EV it would be fine.
Have you considered using the 3.3 cable on the 6.6 and getting a second 3.3 CP installed and using the 6.6 cable for the 3.3 car. That way the max current drawn would be 6.6kW for the two cars. The 3.3 car is limited by the OBC to 3.3kW, and the 6.6 car would be limited by the 3.3 cable to 3.3kW.

If I plug the granny into the 6.6 and the evse cable into the 3.3 it would be fine too. I am trying to find a solution where it is convenient, cost effective and future proof.

ELM327

goz83 wrote: »

Will ask about that



If I plug the granny into the 6.6 and the evse cable into the 3.3 it would be fine too. I am trying to find a solution where it is convenient, cost effective and future proof.

It's convenient and cost effective to limit the cars by the cables. Granny cable only takes 2.2-2.4 kW (mine reports the amps/volts taken so I can see it varies between 2.2-2.4).

However in the interest of future proofing - depending on when you are likely to change car again - I would be looking to upgrade your supply so that you can at least pull 2*7kW. I'm facing the same dilemma, we're in the final stages of buying a house and my first purchase after the house will be rewiring and upgrading supply to allow 2 EV to charge at 7kW. Ideally I'd like to get 3 phase 22kW installed but I am lead to believe that's prohibitively expensive.

KCross

oppenheimer1 wrote: »

With the 6.6kw leaf and the granny cable going you'd be pulling close to 40amps. With a kettle on you will have 10amps for the rest of your house. I'd say you'll need a bit of load management pushing the running of washing machine and dish washer much later into the night.

reboot wrote: »

Very interesting discussion, I guess we need to consider if the average household can deliver such high current drain for two EVs? I doubt if mine would.

Load sharing is the answer. The Tesla solution I outlined earlier in the thread is perfect. The two EVSE's are connected, you set the max current you have available to the two of them combined and then they load share that current.

ei9go wrote: »

I think you can get your supply upgraded to 80 amp.

Yes, you can do that. https://www.esbnetworks.ie/docs/default-source/publications/esb-networks-dac-statement-of-charges.pdf?sfvrsn=16
It costs €1169 for the ESB to come out and change the fuse to 80A. They won't do it until you get an electrician to confirm that your wiring can take the extra current. If its an old house there is a good chance that you would need to upgrade the wire (called tails) from the meter box to the distribution board. You would have to organise and pay that yourself on top of the €1169.

If you use the Tesla load sharing solution you don't need to upgrade. You could have two 7kW cars on your existing supply and it won't exceed the 63A fuse. You can limit them to, say, 48A leaving plenty headroom for other devices.

oinkely

Two leaf family here - on and off anyway.

Currently a 6.6 and a 3.3. When we need to charge both the 6.6 gets plugged into the 32A Rolec and the 3.3 gets granny lead into an external socket. With this configuration the 6.6 is finished before the washing machine or dishwasher or bread machine or whatever else is timed for night rate comes on.

The most difficult part is getting the two cars onto the driveway , which is a bit tight!

goz83

oinkely wrote: »

Two leaf family here - on and off anyway.

Currently a 6.6 and a 3.3. When we need to charge both the 6.6 gets plugged into the 32A Rolec and the 3.3 gets granny lead into an external socket. With this configuration the 6.6 is finished before the washing machine or dishwasher or bread machine or whatever else is timed for night rate comes on.

The most difficult part is getting the two cars onto the driveway , which is a bit tight!

Thanks for posting. Can I ask, is the granny cable plugged into the rolec, or a separate external socket? By your description, it sound to be separate.

oinkely

goz83 wrote: »

Thanks for posting. Can I ask, is the granny cable plugged into the rolec, or a separate external socket? By your description, it sound to be separate.

Separate external socket. It's down the side passage, so going to put another one in a more convenient location so I don't need an extension lead as well as the granny cable. I use this set up 2/3 nights a week with a 13 amp 10 meter extension lead. Note that I have had no problems with this in any weather, i just throw the extension lead and the plug right under the car where it stays nice and dry. probably not best practice but works fine.

My Rolec is an tethered unit so no socket in it.

Shefwedfan

You could sell the second car to me at same price you paid and then no need for second charge point :-)

goz83

So I got a reply from Rolec:

I can confirm that the charge point will charge a 32amp vehicle at full capacity and then using a mode 2 granny lead would trickle charge the 2nd car at around 5-6amps. Please note, removing the Rolec switch for a 48amp version would invalidate your warranty.

oinkely wrote: »

Separate external socket. It's down the side passage, so going to put another one in a more convenient location so I don't need an extension lead as well as the granny cable. I use this set up 2/3 nights a week with a 13 amp 10 meter extension lead. Note that I have had no problems with this in any weather, i just throw the extension lead and the plug right under the car where it stays nice and dry. probably not best practice but works fine.

My Rolec is an tethered unit so no socket in it.

I also have a socket in the side entrance, so I have a couple of options at least.

reboot

A company in London are asking for volunteers for an on the street where you live CPs on lamp posts.
http://chargy. Email hello@ chargy.

KCross

goz83 wrote: »

So I got a reply from Rolec:

I can confirm that the charge point will charge a 32amp vehicle at full capacity and then using a mode 2 granny lead would trickle charge the 2nd car at around 5-6amps.

Thats perfect then. You can safely charge both cars from the one EVSE just that the 3.3kW car will be slower than the normal granny speed(10A).

After charger losses the granny charger would then only charge at a rate of about 1kW so you will need to allow extra time for that car to charge but at least you don't have to worry about switches tripping.

It would be interesting to know if the 6.6kW car is finished would the EVSE then bump the 3.3kW car up from 5A to 10A.

The question is: How can the Rolec command the Nissan granny charger to drop down from 10A? As far as I can tell they are fixed 10A device and it's not possible to signal the g.c. to drop down the rate via a three pin plug.

Maybe the rolec itself will throttle the 32A interface when it detects that the other socket is in use. Wouldn't be the first time if the sales guys didn't know their product.

KCross

samih wrote: »

The question is: How can the Rolec command the Nissan granny charger to drop down from 10A? As far as I can tell they are fixed 10A device and it's not possible to signal the g.c. to drop down the rate via a three pin plug.

Maybe the rolec itself will throttle the 32A interface when it detects that the other socket is in use. Wouldn't be the first time if the sales guys didn't know their product.

Aren't those smarts built into the granny charger itself?
So, if the EVSE knows that the full 30A is being drawn in the Type 2 socket it will limit the power to the 3-pin socket?

Or are you saying the 3-pin socket is not connected to the controller in the EVSE at all and is a fixed 10A all the time?

Yes, the smarts are in the EVSE (Nissan granny). But you can't control the thing externally. It either supplies a predetermined current (10A) or not. In general, controlling a third party EVSE plugged into a regular three pin socket is not possible unless they literally cycle the power of the socket on/off.

IMO, it wold make more sense for the Rolec EVSE to just reduce the output of the main outlet when the other socket is in use. Maybe the unit can sense the load on the three pin socket and can then reduce the main output exactly the required amount to keep within the 40A envelope. If I was designing such a device that is what I'd do as cycling a random device on/off might even damage it. Imagine if you were using the socket for a mower and it was rapidly cycled.

KCross

samih wrote: »

Yes, the smarts are in the EVSE (Nissan granny). But you can't control the thing externally. It either supplies a predetermined current (10A) or not. In general, controlling a third party EVSE plugged into a regular three pin socket is not possible unless they literally cycle the power of the socket on/off.

IMO, it wold make more sense for the Rolec EVSE to just reduce the output of the main outlet when the other socket is in use. Maybe the unit can sense the load on the three pin socket and can then reduce the main output exactly the required amount to keep within the 40A envelope. If I was designing such a device that is what I'd do as cycling a random device on/off might even damage it. Imagine if you were using the socket for a mower and it was rapidly cycled.

The wording of their reply suggests that when the full draw is on the type 2 socket they would limit the power to the 3-pin and so when the granny charger looks for power it will only get 6A and so it will charge at that rate as opposed to the EVSE dynamically commanding it?

Now, if the 3-pin started charging first and is drawing 10A what then happens at the type 2 socket. Does it reduce accordingly or does the 3-pin get reset?

Leafspy on both cars would answer it.

The main thing is that Rolec say its OK to do so I guess he should try it and see what happens.

goz83

KCross wrote: »

The wording of their reply suggests that when the full draw is on the type 2 socket they would limit the power to the 3-pin and so when the granny charger looks for power it will only get 6A and so it will charge at that rate as opposed to the EVSE dynamically commanding it?

Now, if the 3-pin started charging first and is drawing 10A what then happens at the type 2 socket. Does it reduce accordingly or does the 3-pin get reset?

Leafspy on both cars would answer it.

The main thing is that Rolec say its OK to do so I guess he should try it and see what happens.

I have since asked:

Thank you for your reply. I will leave the 40amp RCBO in place, as I would not wish to invalidate the warranty. Is there a reason the granny cable would be trickle charging, as apposed to the tethered cable having a reduced output? It has been said that the EVSE restricting the granny cable has the potential to damage the granny charger.

Can I further clarify the situation where I connect the granny cable to the 6.6 OBC Leaf and connect the tethered cable to the 3.3 OBC Leaf....would the granny cable then work at full capacity?

Finally, do you have domestic solutions for load sharing? The Tesla wall chargers are an example of this, using a Master and up to 3 slave units. I would be very interested to know if there is a Rolec solution to this, where I could add another Rolec unit and use a max of 7KWh between the units if both in use.

goz83

Calahonda52 wrote: »

No wonder He Wept!

Possibly missing something here but if you plug the 3.3 into the 32A it will only draw 16A if I understand the theory correctly and then plug the 6.6 onto the GC or another 16A and have your teat and toast and Eastenders all together

See post #34

goz83

I got a reply from my follow up email:

The granny cable is supposed to trickle charge up to a maximum output of 13amps as per the socket it would be plugged into. It isn’t recommended to use a granny lead for prolonged periods of time as it will drain the battery use quicker. If a granny lead charges a car in say 10 hours while a mode 3 lead takes 4 hourse, you are getting 2 and a half more charges with the mode 3 lead as with the granny lead.

The granny cable would charge at full capacity should you swap the cars over. We don’t offer anything at this moment domestically that offers load sharing, but have something in the pipeline, of which I don’t have any potential dates to give you. All I can say is watch this this space on this one.


Not really sure what he is saying with the granny cable with regards to draining battery. Sales speak perhaps? I would have thought that a slow charge is better for the battery overall, as it produces less heat.

The message appears to say is that they cannot control the granny charger which makes sense as there is no signaling between the wall socket and the granny charger. The only communication happens between the LEAF and the granny charger. There are some non-Nissan portable EVSEs where you can manually select for example a 6 A charge rate but that is not possible with the OEM unit. And even in that case the Rolec unit would not be able to control it.

Thinking back: With a 40 A supply to the Rolec you might *just* get away charging both cars at the same time. As 6.6 kW is just under 29A and the granny charger is 10A you might just be able to charge both simultaneously. However if you plugged in a 7.2 kW i3 or similar instead you would overload the supply.

oppenheimer1

goz83 wrote: »

I got a reply from my follow up email:

The granny cable is supposed to trickle charge up to a maximum output of 13amps as per the socket it would be plugged into. It isn?t recommended to use a granny lead for prolonged periods of time as it will drain the battery use quicker. If a granny lead charges a car in say 10 hours while a mode 3 lead takes 4 hourse, you are getting 2 and a half more charges with the mode 3 lead as with the granny lead.

The granny cable would charge at full capacity should you swap the cars over. We don?t offer anything at this moment domestically that offers load sharing, but have something in the pipeline, of which I don?t have any potential dates to give you. All I can say is watch this this space on this one.


Not really sure what he is saying with the granny cable with regards to draining battery. Sales speak perhaps? I would have thought that a slow charge is better for the battery overall, as it produces less heat.

So is he saying that using the granny gives 2.5 times more "wear" than using a standard charger, because it runs for 2.5 times longer? Doesn't make sense to me that.

Wrt to your issue, I think charging it with the granny that's plugged into a socket on a circuit different from the charger is the easiest and safest.

KCross

goz83 wrote: »

I got a reply from my follow up email:

The granny cable is supposed to trickle charge up to a maximum output of 13amps as per the socket it would be plugged into. It isn’t recommended to use a granny lead for prolonged periods of time as it will drain the battery use quicker.

This must be nonsense. If it were true Nissan UK would not have decided to give everyone in the UK a granny charger!

I also don't believe it chargers "upto 13amps" as they said. I believe its max is 10A? If it went to 13A it would risk blowing the 13A fuse.

goz83 wrote: »

If a granny lead charges a car in say 10 hours while a mode 3 lead takes 4 hourse, you are getting 2 and a half more charges with the mode 3 lead as with the granny lead.

What is that about? What relevance does it have?

The reply sounds like someone in the front office who hasn't a clue as opposed to an engineer replying.

goz83 wrote: »

The granny cable would charge at full capacity should you swap the cars over. We don’t offer anything at this moment domestically that offers load sharing, but have something in the pipeline, of which I don’t have any potential dates to give you. All I can say is watch this this space on this one.

That suggests there is logic built in that decides what power to provide to the 3pin. However, I'm not convinced the person responding really knows.

goz83 wrote: »

I would have thought that a slow charge is better for the battery overall, as it produces less heat.

Heat appears to be only a factor if you are heating the pack beyond its design limit which is quite high(40C+). Not something you need to worry about at any charge rate below 7kW. So, granny charge or 3.3 or 6.6kW charging are all going to have the same effect on the battery.

However, the granny charger is supposed to be the least efficient. I don't have proof of that, just what I read.

samih wrote: »

The message appears to say is that they cannot control the granny charger which makes sense as there is no signaling between the wall socket and the granny charger. The only communication happens between the LEAF and the granny charger. There are some non-Nissan portable EVSEs where you can manually select for example a 6 A charge rate but that is not possible with the OEM unit. And even in that case the Rolec unit would not be able to control it.

I read it that they control the level of power that is available to the 3pin. So, if the type 2 is being used they limit the 3pin to 6A and so when the granny charger starts it simply can't provide any more power to the car than that. Presumably that is possible/allowed?

samih wrote: »

Thinking back: With a 40 A supply to the Rolec you might *just* get away charging both cars at the same time. As 6.6 kW is just under 29A and the granny charger is 10A you might just be able to charge both simultaneously. However if you plugged in a 7.2 kW i3 or similar instead you would overload the supply.

It would just come in under the 40A but if there were high starting currents when the 6.6kW kicked it it might trip it. Would depend on the RCBO and how sensitive it was.

Rolec said it will work but the 3pin is limited to 6A so it sounds like it will be well under the 40A.

What is really needed is goz83 to try it and see what LeafSpy says on each car for the various configurations. It would be interesting.

goz83.... do you have LeafSpy?

goz83

KCross wrote: »

What is really needed is goz83 to try it and see what LeafSpy says on each car for the various configurations. It would be interesting.

goz83.... do you have LeafSpy?

No, I don't have Leaf Spy, but now that I have the Gen1 Leaf, I will be getting it.

I have a crappy android pad (pixi) that I can use with the app....but I see LeafSpy Pro is available on iOS. Does it work properly with apple products?

Also...any links to the best dongles?

KCross

goz83 wrote: »

No, I don't have Leaf Spy, but now that I have the Gen1 Leaf, I will be getting it.

I have a crappy android pad (pixi) that I can use with the app....but I see LeafSpy Pro is available on iOS. Does it work properly with apple products?

Also...any links to the best dongles?

It does work on iOS.
I gave a link to the dongle I used and another poster bought it and it didn't work for them so it seems a bit hit and miss as to whether you get a dongle that works or not.

Sabre Man

KCross wrote: »

You need to ask Rolec if there is load sharing between the 3-pin and the type-2 socket.

If there isn't you might have a problem. If you try to charge the 6.6kW (30A) on the Type 2 and the 3.3kW on the granny cable (10A) at the same time, that is right on the limit of the 40A RCBO on both sides (distribution board and EVSE).

You would need to either swap them so that the 6.6kW is charged on the granny charger (10A) and the 3.3kW (15A) is charged on the Type 2. It would mean making sure you don't mix up the plugs any night or you could end up waking up to two uncharged cars!

I don't think the timers in the cars will help as the granny charger is almost certainly going to overlap with the 6.6kW at some stage of the night.


Slightly left field suggestion.... You did say you didn't want to spend money but I think you should have an eye on the future here. Since you have already decided to be a 2 house EV it is likely that in the long term you could have two 7kW cars parked out front. The best solution I've seen so far is the Tesla Wall Connector one where you have two EVSE's load sharing. You set the max load for the connection and it shares it across the 2 cars.
https://www.tesla.com/en_IE/support/load-sharing-tesla-wall-connector

If you decide to go with a 2nd EVSE you should consider the two Tesla Wall Connector route. You could sell the granny cable and your existing EVSE to cover the two Tesla's!

Which cables do I need to be able to use a Tesla charger with a Leaf?

KCross

The Tesla charger can be ordered with a type 2 socket so for a Leaf it would need to be a type 2<-->type 1 cable.

Sabre Man

KCross wrote: »

The Tesla charger can be ordered with a type 2 socket so for a Leaf it would need to be a type 2<-->type 1 cable.

Would it still be possible to charge a Tesla?

Most cables seem to be type to type 2. I did find some on an Australian site but I don't know if they can be used here. Does anyone have a link or more information about type 2 to type 1 cables?

I contacted Tesla several days ago but received no reply so far.

KCross

A tesla needs a type 2 so you would either use a tethered charger or else a type 2<-->type 2 cable

Sabre Man

Let me see if I got this right. I find all these cables very confusing.

A Tesla charger can be ordered with a type 2 socket (tethered), which means it can charge a Tesla direcly.

Would I not then need a type 1 to type 2 cable to use the same charger with a Leaf?

A type 2<-->type 2 cable sounds just like a normal extension cable. This is just for an untethered charger, right?

KCross

Two types

1) tethered
2) untethered

1) this will have a type 2 end on it so not suitable for a Leaf

2) this is a type 2 socket. one end has to be type 2. The other end can be type 1(Leaf) of type 2(tesla etc)

BoatMad

KCross wrote: »

Aren't those smarts built into the granny charger itself?
So, if the EVSE knows that the full 30A is being drawn in the Type 2 socket it will limit the power to the 3-pin socket?

Or are you saying the 3-pin socket is not connected to the controller in the EVSE at all and is a fixed 10A all the time?

You cant " control " power to the attached 13A socket

what happens is the EVSE socket signals the car to reduce power so as to keep the total power consumed within limits

the 13A will deliver all the power it can up to the fuse limit

BoatMad

goz83 wrote: »

I got a reply from my follow up email:

The granny cable is supposed to trickle charge up to a maximum output of 13amps as per the socket it would be plugged into. It isn’t recommended to use a granny lead for prolonged periods of time as it will drain the battery use quicker. If a granny lead charges a car in say 10 hours while a mode 3 lead takes 4 hourse, you are getting 2 and a half more charges with the mode 3 lead as with the granny lead.

The granny cable would charge at full capacity should you swap the cars over. We don’t offer anything at this moment domestically that offers load sharing, but have something in the pipeline, of which I don’t have any potential dates to give you. All I can say is watch this this space on this one.


Not really sure what he is saying with the granny cable with regards to draining battery. Sales speak perhaps? I would have thought that a slow charge is better for the battery overall, as it produces less heat.

ignore virtually every sentence in that reply .....:eek:

BoatMad

just to explain how AC mode 2 charging works , for Type 1 and Type 2 sockets

A 1Khz signal ( The control pilot ) is generated by the EVSE ( the CP on the wall , or the electronics in the granny cable ) This is a 12 Volts signal , for a specific duty cycle , a " maximum " current the car can draw is " advertised

16% duty cycle is 10 A, 25% is 16 A, 50% is 32 A, and 90% flags a fast charge option. ( some cars have a full variable response to a variable duty cycle ) . The leafs lowest charge rate is 6A. Maximum charging current under mode 2 is 32A

Note that the EVSE , ( CP ) has no ACTUAL control over the power drawn , thats solely the determination of the charger in the car . If the car ignored the duty cycle it can in effect do what it likes, blowing the supply fuse in the process

The charging standards are set out in IEC 61851 , but mode 2 is derived from the US SAE spec , J1772 signalling. Its a very simple system and Ive implemented it myself in serval "home " designs

The car signals the start of charging by placing a resistance in the control pilot circuit , the EVSE ( CP ) , then releases the contractors , the cable being dead until charging actually starts . The car can signal a fault or overheat situation by placing different resistances on the control pilot circuit.

The only difference as regards signalling in a Type 2 plug ( Zoe, Ioniq) as against a type 1 ( Leaf) is that the Type plug supports 3-phase AC charging ( same signalling ) , and has a specific resistance between the the Proximity pilot ( the other control line) and earth to indicate the maximum rated amperage of the cable to the car.


Hence the proper solution for two car charging is a Dual capable EVSE. to be effective this needs to be load sensing , i.e. the EVSE senses the house load and requests the car to reduce charging current to maintain the overall rated maximum current . Im not aware such a thing is on the market , but it cant be far of.

( There is an issue where certain cars will not respond to a change in current request , once they start charging , you have to abort the charge and re start the cycle at a different current request ) , also some cars ( it seems ) only support 10A, 16A or 32A, steps and not variable steps

( I have built such a EVSE as a prototype , but at present Im not doing anything with it )