Higher Current EVSE

[gnuarm.del...@gmail.com]

Seems like this group doesn't get a lot of traffic.  I quickly reached 2015 when looking back through several topic areas.  So I'm posting this without digging through the whole set of topics.

I'm interested in a higher current version of OpenEVSE.  I haven't found all the design documents yet, but from the assembly docs it would appear the only limitation to a higher current version would be the relay and the charging cable.  I would like to be able to charge my Tesla model X at the full 72 amps it is capable of.  That would be 90 amps on the relay and cables.  Is there any interest in this?  It would bump up the cost of the relay by $100 or so.  Don't know how much more expensive the cable would be.  I assume some mods to the firmware would be required. 

Any thoughts?

  Rick C.

  Tesla referral code - https://ts.la/richard11209
  Get 6 months of free supercharging

[chris1howell]

OpenEVSE suports the full J1772 current range from 6A to 80A. We do have a few 80A tesla cables (not currently listed in the store) and 90A contactors. Send an email to sup...@openevse.com and we will send you a quote.

--
You received this message because you are subscribed to the Google Groups "OpenEVSE" group.
To unsubscribe from this group and stop receiving emails from it, send an email to openevse+u...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.

[Sam C. Lin]

No firmware mods needed. It already supports the max 80A of the standard

--

[Nuno Leitao]

I have a 90A relay and 32A cable on mine. My car charges @13A.

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten
Nuno Leitão

[gnuarm.del...@gmail.com]

On Sunday, December 23, 2018 at 2:33:52 AM UTC-5, Nuno Leitao wrote:

I have a 90A relay and 32A cable on mine. My car charges @13A.

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten
Nuno Leitão

On Sun, Dec 23, 2018 at 3:30 AM Sam C. Lin <linco...@gmail.com> wrote:

No firmware mods needed. It already supports the max 80A of the standard

 

From: open...@googlegroups.com <open...@googlegroups.com> On Behalf Of gnuarm.del...@gmail.com
Sent: Saturday, December 22, 2018 3:49 PM
To: OpenEVSE <open...@googlegroups.com>
Subject: Higher Current EVSE

 

Seems like this group doesn't get a lot of traffic.  I quickly reached 2015 when looking back through several topic areas.  So I'm posting this without digging through the whole set of topics.

 

I'm interested in a higher current version of OpenEVSE.  I haven't found all the design documents yet, but from the assembly docs it would appear the only limitation to a higher current version would be the relay and the charging cable.  I would like to be able to charge my Tesla model X at the full 72 amps it is capable of.  That would be 90 amps on the relay and cables.  Is there any interest in this?  It would bump up the cost of the relay by $100 or so.  Don't know how much more expensive the cable would be.  I assume some mods to the firmware would be required. 

 

Any thoughts?

 

  Rick C.

 

  Tesla referral code - https://ts.la/richard11209
  Get 6 months of free supercharging

That somehow just seems wrong! 

  Rick C.

  - Get 6 months of free supercharging
  - Tesla referral code - https://ts.la/richard11209

[Nuno Leitao]

Why? Because I had a bigger initial investment?

I'm planning to buy my second electric car now, it charges @32A, no changes will be needed. 

90A relay will have much less wear out, the cost was slightly higher... 

I would do it again.

--

[gnuarm.del...@gmail.com]

On Sunday, December 23, 2018 at 1:18:44 PM UTC-5, Nuno Leitao wrote:

Why? Because I had a bigger initial investment?

I'm planning to buy my second electric car now, it charges @32A, no changes will be needed. 

90A relay will have much less wear out, the cost was slightly higher... 

I would do it again.

 

Don't get me wrong, I'm a big proponent of future proofing expensive installations.  Why would the car only charge at 13 amps?  That seems so slow.  Is that all it is capable of? 

I'm driving a Tesla model X and some of the time I charge from 120 volts, 12 amps.  It takes DAYs to fill the tank, so you can see my surprise.  Fortunately I don't often need to actually fill the tank when here.  lol

I'm here because I want to explore the options of charging at 72 amps, my highest possible rate.  Seems they have versions of OpenEVSE up to 80 amps.  Still waiting for pricing which I probably won't see until after the holidays.

  Rick C.

  + Get 6 months of free supercharging
  + Tesla referral code - https://ts.la/richard11209

[gnuarm.del...@gmail.com]

On Sunday, December 23, 2018 at 1:18:44 PM UTC-5, Nuno Leitao wrote:

Why? Because I had a bigger initial investment?

I'm planning to buy my second electric car now, it charges @32A, no changes will be needed. 

90A relay will have much less wear out, the cost was slightly higher... 

I would do it again.

BTW, where did you get the 90 amp relay and how much is "slightly higher"?  I ask because I am finding large price differences.  40 amp relays are maybe $30 USD.  90/100 amp units seem to be over $100.  There are some cheaper on eBay, but I don't know if I should trust them. 

  Rick C.

  -- Get 6 months of free supercharging
  -- Tesla referral code - https://ts.la/richard11209

[Nuno Leitao]

I have a Peugeot iOn, it's a Mitsubishi iMiev clone. 

It has 16kw bat, and yes the maximum is 13A. Normally I charge at the minimum from this EVSE, 6A.

I just use normally 2h charging per day @6A 😊

--

[Nuno Leitao]

To be honest I have no idea how higher is slightly; I didn't paid it. 

If I remember I'll ask here in Belgium the prices in January when I'm back in the company.

[Marcin Chojnowski]

But the amps you want to charge your Model X doesn't need any design changes to the board just beefier relay. Also I think also that you can't compare relays switching heavy load to EV as what I have noticed not much current is being drawn when relay contacts close and open. At least my EV ramps up current very slow and way later than relay is already closed. I'm not sure that such huge relay overhead is necessary. 

--

[Nuno Leitao]

Indeed, I'm just not sure how fast will it lower the current when disconnecting the plug.

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten
Nuno Leitão

[Marcin Chojnowski]

This happens well before relay opens in case you press the plug button. On the other hand when you mostly charge at night when battery is almost full the current flowing into the car is very low well less than 10A before car decides it finished charging and evse can open relay.

Affordable relays in my opinion are 

Omron G9EA-1-B-CA-DC12 

[chris1howell]

The SAE J1772 Spec allows the vehicle 100ms the stop pulling current when the button is pressed.

By the time the handle is removed and the relay is opened, there is no significant current on the relay.

[EV@TucsonEV]

How far does a hand/plug move when pulled out of the inlet in 100ms?

 

Best regards,

 

Rush Dougherty

TucsonEV

1014 E King St

Tucson AZ 85719

520 240 7493

www.TucsonEV.com

 

 

 

Virus-free. www.avg.com

 

[Marcin Chojnowski]

You press the button before you pull. Nothing complicated here. 

[chris1howell]

J1772 proximity is actually a two stage process. In a well built handle the button clicks early in the button/latch travel. By the time the button clicks the latch should be less than half way clear. Once the latch is fully clear then the handle can start to be pulled out. 

For a normal person 100ms has already lapsed by the time the button is pressed in fully. I suppose if you try really hard you could press the button very fast and yank it out quickly but it is unlikely very many people could do it in less than maximum 100ms. It is far more likely the vehicle electronics are working the whole process significantly faster than the maximum allowed.

Chris

[Glenn Drayer]

If you are in the USA I have a 90A Eaton contactor fort $25 shipped. I replaced it with a 65A unit to try out. Both  shake the garage but I think the 90A unit is louder. I just wanted to see if the 65A unit would handle my 40A B (it does fine). I am sorry but I do not do customs.

 

--------- Original Message ---------

Subject: Re: Higher Current EVSE

--

[lincomatic]

Either your car only wants 13A, or you have the maximum current set too low

Sent from my iCrap

[lincomatic]

Oops, ignore my last reply,  didn’t see this until after I posted 

Sent from my iCrap

--

[Glenn Drayer]

It sounds like you are in Europe. Additional hardware is needed to support the Konike standard (not  spelled right) but Chris can tell you what you need. By the way the built in current meter is only accurate to one amp so it could have been 12A. In a version a long time ago Sam removed the decimal

point after a ground swell he had to put it back.

--------- Original Message ---------

Subject: Re: Higher Current EVSE

[Glenn Drayer]

[EV@TucsonEV]

Chris and all,

 

Well, I guess I need to be more specific…

 

I know that the time elapsed once the button is pushed until movement of the plug is probably more than 100ms. What if there is no proximity circuit attached to the button? Does the physical distance difference between the pilot pin and ground pin that is traveled cut the pilot circuit fast enough so that there is no hot disconnect?

[chris1howell]

The pilot pin is not really a substantially different length, a mm or two at most. Additionally, the vehicle has 5 seconds to respond to changes in the pilot. 

Using a J1772 plug without proximity or a broken latch will result in dangerous conditions including arching and premature failure. 

Chris

[EV@TucsonEV]

I’m talking about the EVSE, not the EV.

 

The J1772 Spec  - Table 8, transition 2, from State C to State A says that the EVSE Response time is 100ms maximum “delay from disconnect until the contactor opens and terminates AC energy transfer.”

 

Does the plug move, in that 100ms maximum, the distance necessary to terminate the pilot signal so that the energy transfer is terminated and therefore no hot disconnect?

 

Again, I’m not talking about the proximity signal, I’m talking about the pilot signal in the EVSE only…

 

The pilot signal connection is electronically the last in and the first out. I think that the actual connection length is approx 1cm, not 1-2mm.

[chris1howell]

Your guess is as good as mine, I would guess the pins seperate faster than 100ms. There is a big differance in the responsibility though. Proximity/EV is to remove all current. Pilot/EVSE is to ensure the lines are no longer hot after the plug is disconnected. Proximity had better have already removed the current before the EVSE tries to open the relay. If not there will be arching at the relay and or the plug. You really do not want that to happen at eirher place. Bottom line is proximity is the first line of defense.

[Nuno Leitao]

I was not aware of this feature of the pilot, I guess I should had read more.
I made with a 90A relay because I thought it could cut under current.
In this case I will change my 90A relay for a 40A relay, maintaining the 3 phase relay design. It will allow me to make the casing smaller.

I only have 45A at home and my bigger fuse is 32A; on the garage I have 20A fuse; so no problem at all.

thank for the info over the pilot.

 

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten
Nuno Leitão

[Nuno Leitao]

I just realized something

It was said above, the has 5 seconds to respond to the Pilot, this means, very likelly you break the hot connection pulling the cable... Am I wrong?

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten / Sincères amitiés
Nuno Leitão

[gnuarm.del...@gmail.com]

The pilot is not used to disconnect the cable from the car.  To remove the connector you have to push the unlock button which controls a separate circuit with resistors that the car uses to "see" that the car is connected to a cable so the car can't be driven.  When the button is pushed one resistor is shorted out and the car sees this as a disconnect signal and stops drawing power immediately before you have a chance to actually pull the plug.

Rick C.

[Nuno Leitao]

Now it's clear, thank you for the explanation Rick.

-----

Cumprimentos   /   Kind Regards  /  Met vriendelijke groeten / Sincères amitiés
Nuno Leitão

[gnuarm.del...@gmail.com]

I learned about the J1772 interface last year and I found many sources of info to be contradictory and confusing.  Asking questions here is the best way to get things straight I think.

Rick C.