thomash85715
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Re: Modifying the EVSE charger?

Tue May 02, 2017 3:40 pm

Has anyone ever parked their i-MiEV next to a leaf and swapped the stock EVSE? In other words, has anyone empirically verified that the 8 amp lock at L1 is programmed into our factory units? What current draw as measured by a Kill-A-Watt occurs when a factory leaf EVSE is plugged into one of our cars? Or vice versa? I guess I need to make friends with a local leaf-er and buy him lunch to find out.
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

Don
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Re: Modifying the EVSE charger?

Tue May 02, 2017 3:59 pm

A Leaf EVSE as well as a 2014 iMiEV EVSE will charge your car on 120 volts at 12 amps - No 240 volts though

. . . . and, your stock 8 amp EVSE will charge either a Leaf or a 2014 iMiEV (or any other EV you choose to name) at 8 amps and no more, the same as it does your car - It's all in the EVSE - The EVSE 'talks' to the car

The EVSE's 'handshake signal' tells the car how much current it can safely pull from the wall and the car's charger sets itself to draw only that amount of current and no more - It's all in the EVSE and our stock EVSE is telling the car not to draw any more than 8 amps, so it doesn't. Some EVSE's have adjustable current and some don't. The one from EVSE Upgrade does . . . . that's part of the 'upgrade' as is the 240 volt capability

How fast (and how many amps) you can charge any EV is determined by many factors. The household wire gauge feeding the EVSE outlet, the fuse size on that circuit, whether or not that fuse is powering anything else besides the EVSE, the gauge of the wire between the EVSE and the car (our EVSE wire is only 16 gauge, so we're limited to 12 amps because of that wire choice) and the maximum capability of the EVSE itself. What the charge current will be is always determined inside the EVSE and in some EVSE's (like ours) that current is permanently set in the software within the unit - If you could change the software you could change the current assuming of course you don't exceed any of the other limiting factors I mentioned

Mitsu was very conservative when they limited our EVSE to only 8 amps, but they didn't know if the outlet in your garage was also powering your refrigerator or your clothes washer or something else. It's very common for a garage 120 volt outlet to share a fuse (and sometimes a feed wire) with other circuits. Early on, Mitsu was scheduling an electrical 'survey' for the home of each buyer - They had set it up for the 'Geeks' at Best Buy to do the surveys. My thinking is it was probably a ploy to sell and install L2 EVSE's since it was obvious that not many buyers were going to be happy with the 20 hour recharge time using the unit provided with the car

Don
2012 iMiEV SE Premium, White
2012 iMiEV SE, White
2014 Ford Transit Connect XLT SWB wagon, 14,000 miles
1994 Miata 60K miles - Soon to be sold
1979 Honda CBX six into six

thomash85715
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Re: Modifying the EVSE charger?

Tue May 02, 2017 11:25 pm

Sorry to be asking same sort of questions over and over. Each time I learn a new layer. Now if I could just retain it all.
The guy in Gilbert AZ who is selling the Duosida aftermarket EVSE for $200 on ebay and CL states that the charger in the car tells the EVSE what rate to operate on L1. If he is correct, then putting a EVSE that wants to run at 12A on 120V will not be a successful enterprise. He states that his chevy volt has a dashboard switch or way to choose 8 or 12A on L1 and that if the mitsu charger is set to draw 8, that will be the limit. This is at odds with what you all say on here but I am more inclined to go along with the wisdom here.
I am quite certain that this plug I use for L1 at my house will handle 12A for the car.
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

kiev
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Re: Modifying the EVSE charger?

Wed May 03, 2017 4:42 am

The EVSE sends a PWM signal that indicates it's maximum current sourcing capability. The charger in the car decides how much current it actually wants to draw at any given time, up to that maximum amount.

The charger has a power rating of 3,300 Watts. Power is Volts x Amps, so 120V x 12 A does not exceed the charger's rating--it can easily handle that. 240V x 12A , it can easily handle that also.
kiev = kenny's innovative electric vehicle

thomash85715
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Re: Modifying the EVSE charger?

Wed May 03, 2017 5:53 pm

You know you need to dial it back when you reply to your own postings but I just found this:

https://www.ev-power.eu/Electric-Cars/E ... param=EVSE

It costs $50 and is a DIY L1 setup that gives user control over the current draw using PWM control. Wonder if anybody has done this?
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

kiev
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Re: Modifying the EVSE charger?

Wed May 03, 2017 6:55 pm

That's an interesting little kit to start building a diy EVSE, but it is missing the proximity signal line carried on pin 5 of the connector. That line tells the car that you are fully plugged in and the handle is locked, and is also used to signal a shutoff request when you pull the trigger to disconnect. You would never want to connect or disconnect with current flowing or live mains voltage on the terminals in the handle.
kiev = kenny's innovative electric vehicle

thomash85715
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Re: Modifying the EVSE charger?

Wed May 03, 2017 8:52 pm

There is a diagram on wikipedia showing the parts associated with that disconnect circuit through the button. These pieces they sell go INSIDE the existing J1772 connector so it would be a simple matter to integrate those handful of resistors into the button so the charger in the car will see the proper signal during connect and disconnect. They show PWM oscillographs of three different current draw conditions and a little pot you can rig up to dial in the current as desired.
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

PV1
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Re: Modifying the EVSE charger?

Thu May 04, 2017 8:41 am

Even just going to 12 amps at 120 volts almost cuts charge time in half for a full recharge, so it's much more practical than the stock 8 amps.

The highest I've seen my on-board charger go is 14 amps. I charged from a 30-amp level 2 station last weekend that was only giving 197 volts (208V source with a long wire run), but the car didn't go higher than 14 amps (total charging power of 2.7 kW, so the charger wasn't maxed out on power).
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
Solar-powered since 10/10/2013

"Koorz" - 2012 Cool Silver Metallic ES with QC - 1/5/2015

2017 Bolt EV LT in Orange with QC - 7/31/2017

Driving electric since 2-21-2013.

thomash85715
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Re: Modifying the EVSE charger?

Thu May 04, 2017 11:30 am

All this is thoughtful and good advice which I appreciate. I would have to run single phase 120V extension from as yet undetermined place in my house to experimentally come up with two opposite phase legs at my carport. It would be easier to parallel off the dryer plug and not try to charge and dry at same time.
Right now am hoping for the czech solution to pan out. It seems like no one on here as built that yet. I would be the first! It all goes inside the j1772 connector head. I would write down the connections as they exist now on my factory EVSE before modifying it of course.
Yes I should do some math to figure out payoff point for the EVSE upgrade using the retail price. I just hate paying retail for anything; that is part of this.
In an insane society a sane man would appear insane.
Acquired 2012 silver ES April 2017.

Phximiev
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Re: Modifying the EVSE charger?

Thu May 04, 2017 1:36 pm

Need a different kind of charger?

https://youtu.be/KT86ICX6VsI
2012 iMIEV ES
2014 Chevy Volt

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