MadTechNutter
Posts: 128
Joined: Fri Jul 05, 2019 7:35 pm
Location: Aussie Land

Regulated Solar Charging

Fri Jul 05, 2019 8:35 pm

This is my first post.
I am an electronic enthusiast and this post is mainly addressed to like minded, who are aware NOT to hold a soldering iron by it's business end :)

I will be proud owner of a reasonably priced, used PHEV (2014) next week, which will be out of warranty soon.
I am cash poor and had to save long for this.
I live in a country where there is lots of sun, Australia.
I have solar with a DIY off-grid LiFePO4 battery system but want to beef it up.
For the price of a charge adjustable EVSE cable down to 6A, I can purchase 6 x 250W solar panels here, which I will, bringing my off-grid system to 3kW(realistically 2.5kW). There is a grid tied 1.5kW as well where I might syphon off unused energy to the off-grid battery, but that is not the topic.

The objective is to open the Mitsu charge cable box, locate the 1khz pilot and the +/- 12V, cut the pilot wire and trigger with it a 555 timer chip in monostable configuration so it outputs a pulse that can be adjustable between 50-250µsec, feed it to a buffer amp that swings between the +/-12V and connect it back to the pilot wire that goes into the Mitsu.

Furthermore a current sensor in the PV dc line will regulate this PWM signal depending on Solar output.

I actually want to do this with a PIC micro 12F683, just mentioned the 555 to explain the function better.

My Questions:
1 - Are the required wires accessible in the Mitsu supplied controller box and not fully immersed in resin?
2 - Has anybody done this before?
3 - Could the car charge at lower than 6A if the Pilot pulse is less than 10% of the full cycle?
4 - Does the vehicle respond to changes in the PWM duty cycle while charging?

Practically I can do this for $2 material cost and have designed far more complicated things, currently designing/building a 4WD electric mini tractor/ride-on, all drive by wire, later maybe autonomous.

ATM I have no clue what else I will be doing with this PHEV but I already know that the only way to stop me from 'disfiguring' it,
will be to pry the soldering iron from my cold dead hands.

I might think about changing the way the throttle responds like a 'pure' EV mode which I read here: http://www.myoutlanderphev.com/forum/vi ... =10&t=2191
but Vtech ended up selling this https://evtun.com/phev-box.html
To me that just looks like a pre configured throttle potentiometer response curve that I could do with a $1 PIC micro.
I will see how I get on when I can finally drive it, if such a function is actually useful. I am NOT the lead footed type of person but if I find it difficult to drive up the minor slopes which I have on my daily drive without the ICE kicking in, I might look into it.

Unfortunately I am only a hardware geek and know nothing about any engine mapping codes.
It would seem beneficial to have short term higher EV kW output when I need it without the ICE.

In the end it is all about MOSFETs or IBGTs that are controlled with a DC/PWM signal.
My motto: Hardware overrides Software :)
This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.

jaapv
Posts: 4582
Joined: Mon Dec 16, 2013 1:18 pm
Location: Netherlands

Re: Regulated Solar Charging

Sat Jul 06, 2019 12:07 am

Much of this is gobbledegook to me ;) but I can tell you that the wires are not embedded in resin.
However, the charge box and the car software do communicate, so I cannot tell you whether the system will accept changes in the hardware configuration.
Instyle 2019
Titanium Grey
Before:
Instyle+ 2013

msmatt
Posts: 26
Joined: Tue Sep 11, 2018 5:42 pm
Location: Ontario, Canada

Re: Regulated Solar Charging

Fri Jul 12, 2019 6:48 pm

I found these sites while researching chargers a few years ago. Good info on how Level 2 charging is controlled. Is sounds like you are skilled, so might be of some use to you. My understanding is the charger indicates it's maximum available capacity and the car requests variable amount of current up to the charger's max capacity using the +/-12V square wave pilot signal. The Hydra design was good for adjusting the output based on the available source power.

Open EVSE - https://www.openevse.com/kits.html

J1772 Hydra - https://www.tindie.com/products/nsayer/j1772-hydra/

I had a desire to build an EVSE, then they became available on Amazon for $250, so that went away quick.

Tai626
Posts: 115
Joined: Sat May 19, 2018 7:01 am
Location: Los Angeles, CA, USA

Re: Regulated Solar Charging

Fri Jul 12, 2019 11:48 pm

With that much tinkering, I would tap into the Chademo directly. No DC to AC then AC to DC lost. Perhaps you can charge with (100) LIFEPO4 in series!

Tai
Outlander PHEV SEL pearl white - MY2018

MadTechNutter
Posts: 128
Joined: Fri Jul 05, 2019 7:35 pm
Location: Aussie Land

Re: Regulated Solar Charging

Sat Jul 13, 2019 2:01 am

Thanks for the replies :)
Yes I was looking into making one from scratch but the kits aren't that cheap either, although I found cheaper boards but lost the links.

Would love to 'mess around' with Chademo but we Aussie's are not allowed to have that port, just a blank space and no hidden wires behind it either.

I managed to get the supplied charger apart 'carefully' with a chisel and there is a lot more inside it than I thought and not a matter of simply cutting a wire.

Was hoping there was an external oscillator where I could simply change the duty cycle but the signal is internally fixed programmed in an MCU.
A timer to modify the duty cycle between PWM_out from the MCU and the buffer amp could be a solution but the feedback of the modified Pilot
back into PWM_in of the MCU might make it shut down.


Edit found the link, this is the little board I meant for $50:
https://www.ev-power.eu/Electric-Cars/E ... param=EVSE
Github has all the info how to use it: https://github.com/kortas87/simple-evse ... deExternal

I particularly like this version :)
However I would never use this without an RCD !!

Image
This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.

elm70
Posts: 1156
Joined: Mon Sep 26, 2016 11:18 pm
Location: Poland
Contact: Website

Re: Regulated Solar Charging

Mon Jul 15, 2019 3:36 am

MadTechNutter wrote:This is my first post.
I am an electronic enthusiast and this post is mainly addressed to like minded, who are aware NOT to hold a soldering iron by it's business end :)

I will be proud owner of a reasonably priced, used PHEV (2014) next week, which will be out of warranty soon.
I am cash poor and had to save long for this.
I live in a country where there is lots of sun, Australia.
I have solar with a DIY off-grid LiFePO4 battery system but want to beef it up.
For the price of a charge adjustable EVSE cable down to 6A, I can purchase 6 x 250W solar panels here, which I will, bringing my off-grid system to 3kW(realistically 2.5kW). There is a grid tied 1.5kW as well where I might syphon off unused energy to the off-grid battery, but that is not the topic.

The objective is to open the Mitsu charge cable box, locate the 1khz pilot and the +/- 12V, cut the pilot wire and trigger with it a 555 timer chip in monostable configuration so it outputs a pulse that can be adjustable between 50-250µsec, feed it to a buffer amp that swings between the +/-12V and connect it back to the pilot wire that goes into the Mitsu.

Furthermore a current sensor in the PV dc line will regulate this PWM signal depending on Solar output.

I actually want to do this with a PIC micro 12F683, just mentioned the 555 to explain the function better.

My Questions:
1 - Are the required wires accessible in the Mitsu supplied controller box and not fully immersed in resin?
2 - Has anybody done this before?
3 - Could the car charge at lower than 6A if the Pilot pulse is less than 10% of the full cycle?
4 - Does the vehicle respond to changes in the PWM duty cycle while charging?

Practically I can do this for $2 material cost and have designed far more complicated things, currently designing/building a 4WD electric mini tractor/ride-on, all drive by wire, later maybe autonomous.

ATM I have no clue what else I will be doing with this PHEV but I already know that the only way to stop me from 'disfiguring' it,
will be to pry the soldering iron from my cold dead hands.

I might think about changing the way the throttle responds like a 'pure' EV mode which I read here: http://www.myoutlanderphev.com/forum/vi ... =10&t=2191
but Vtech ended up selling this https://evtun.com/phev-box.html
To me that just looks like a pre configured throttle potentiometer response curve that I could do with a $1 PIC micro.
I will see how I get on when I can finally drive it, if such a function is actually useful. I am NOT the lead footed type of person but if I find it difficult to drive up the minor slopes which I have on my daily drive without the ICE kicking in, I might look into it.

Unfortunately I am only a hardware geek and know nothing about any engine mapping codes.
It would seem beneficial to have short term higher EV kW output when I need it without the ICE.

In the end it is all about MOSFETs or IBGTs that are controlled with a DC/PWM signal.
My motto: Hardware overrides Software :)
Time few weeks, and you will master to press the accelerator without having the ICE to start up

It is hard to use 99% of all power without kick in the ICE ... but to get 90% it is not so complicated, and you will master this in a relative short time

MadTechNutter
Posts: 128
Joined: Fri Jul 05, 2019 7:35 pm
Location: Aussie Land

Re: Regulated Solar Charging

Mon Jul 15, 2019 5:28 am

Thanks elm70.
I discovered if I go just 5km/h over the speed limit shortly before the hill on the highway I get to the top with help of the extra inertia without slowing traffic behind me.
The police generally don't book you here with 5k's over and they always stand on the down hill stretches anyhow.
That is where I am harvesting nicely with the paddles keeping it spot on 80. Never thought keeping to the speed limit is so much fun :lol:
This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.

MadTechNutter
Posts: 128
Joined: Fri Jul 05, 2019 7:35 pm
Location: Aussie Land

Re: Regulated Solar Charging

Mon Jul 15, 2019 6:11 am

Definitely going to build my own charger though, the supplied charger is a design nightmare. Just holding a 1MΩ test probe on the PWM signal switches on the fault LED.
It was good that I took it apart though because a plug and wire on the power relay had signs of heat damage.
Turned out it was corroded bad, possible fire hazard. All the other connectors are perfect and no sign of moisture ingress.
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Last edited by MadTechNutter on Mon Jul 15, 2019 6:23 am, edited 1 time in total.
This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.

MadTechNutter
Posts: 128
Joined: Fri Jul 05, 2019 7:35 pm
Location: Aussie Land

Re: Regulated Solar Charging

Mon Jul 15, 2019 6:22 am

Here a close-up of the corroded plug, nasty stuff:
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This era of thoughtless consumption must end so we can encourage a world of creative geniuses rather than consumer idiots.

wws
Posts: 25
Joined: Thu Jan 17, 2019 10:17 am
Location: Northern California

Re: Regulated Solar Charging

Wed Jul 17, 2019 12:50 pm

You might consider just building your own EVSE, e.g, from: https://www.openevse.com/ Then you can set the amperage to whatever you please.
2018 Tesla Model 3
2016 Chevy Volt
A few other ICE vehicles (considering replacing one with an Outlander PHEV)

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