aarond12
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Re: Add DC quick charger?

Sun Mar 17, 2013 5:43 pm

Looking through the CHAdeMO specs, it implies the DC charging station will vary its voltage to what the car needs. If our car needs 330VDC (or slightly more as many standard battery chargers do), the charging station will supply the required voltage. That makes sense to me since the DC charging stations are HUGE whereas regular AC EVSE are small.

There are 10 "pins" in the CHAdeMO standard too. Much more handshaking is going on using the CAN-BUS. probably to pass voltage and amperage parameters to the DC charger. In theory, that would bypass any need for the on-board charger to do anything but allow direct access to the batteries for charging. (There might be some cell balancing going on...?)

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jray3
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Re: Add DC quick charger?

Fri Mar 22, 2013 9:48 am

Thanks for posting that diagram. With all indications that the main (charging) contactor is shared by J1772 and CHAdeMO, that would put the vast majority of added cost for the option on the inlet and cables. (Which retail for approx 150% the original option price.) I'm betting that all of the small wires are in the main wiring bundle, and we've got a dead-end connector on non-CHAdeMO cars. Perhaps the little 12V relay was not installed on non-CHAdeMO cars as well.
That leaves software as the main variable in my mind. If the CHAdeMO protocol is firmware that's programmed based upon each car's final options package at the factory, there may be no practical way to add the option even if all hardware is in place.

BUT- if 330V appears on the two big pins when J1772 charging is underway, that opens up a world of DIY possibilities... :shock:
Anybody have a chance to check on this yet? I've confirmed on a friend's LEAF that the CHAdeMO pins are not hot during L1 or L2 charging, but the LEAF has multiple contactors that click on when initiating a charge...
2012 i-SE "MR BEAN" 70,000 miles
i-ES traded at 21,648 miles
2000 Honda Odyssey
1987 F250 Diesel
1983 Grumman Kurbwatt,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
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Don
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Re: Add DC quick charger?

Fri Mar 22, 2013 11:59 am

jray3 wrote:I'm betting that all of the small wires are in the main wiring bundle, and we've got a dead-end connector on non-CHAdeMO cars. Perhaps the little 12V relay was not installed on non-CHAdeMO cars as well.
That's quite a bet! Please make sure it's a correct assumption before you buy any expensive parts you can't return
That leaves software as the main variable in my mind. If the CHAdeMO protocol is firmware that's programmed based upon each car's final options package at the factory, there may be no practical way to add the option even if all hardware is in place.
I'm betting that's the more likely scenario - The option costs $750 from the factory for a reason - I doubt they would be charging us that much just to install the plug and a few wires

Don
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2012 iMiEV SE, White
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PV1
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Re: Add DC quick charger?

Sat Mar 23, 2013 12:00 pm

jray3 wrote:BUT- if 330V appears on the two big pins when J1772 charging is underway, that opens up a world of DIY possibilities... :shock:
Anybody have a chance to check on this yet? I've confirmed on a friend's LEAF that the CHAdeMO pins are not hot during L1 or L2 charging, but the LEAF has multiple contactors that click on when initiating a charge...

Same story on the i. The pins ARE NOT hot during L1 charging. Maybe the contactor has three positions. In the center position, neither CHAdeMO or L1/L2 has battery voltage. In one of the ON positions, L1/L2 gets battery voltage, and the third position gives CHAdeMO battery voltage. I don't know what type of contactor the i has, but the type I mentioned wouldn't be hard to manufacture. +12 volts gives L1/L2 the voltage, -12 volts gives CHAdeMO the voltage, and 0 volts is OFF.

As far as software, it wouldn't make much sense for the hardware be remotely available to us if the car didn't have the code to use the port. I would imagine that the software would be there, because paying somebody to go through the MiEV system and remove CHAdeMO-related code would cost Mitsubishi more money than just leaving it there, not to mention the decrease in production by having to reprogram every non-CHAdeMO vehicle that comes off the line. This could be similar to my Windows tablet. I got the tablet cheaper because a feature was left off of it (NFC). Instead of Samsung changing the code and circuit board, they just simply left off the antenna, rendering the NFC chip useless. If I really wanted to, I can restore this feature by opening the tablet and soldering on an antenna. I still have the options and settings for NFC, as well as Windows updates including NFC drivers.
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Don
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Re: Add DC quick charger?

Sat Mar 23, 2013 12:14 pm

PV1 wrote:I don't know what type of contactor the i has, but the type I mentioned wouldn't be hard to manufacture. +12 volts gives L1/L2 the voltage, -12 volts gives CHAdeMO the voltage, and 0 volts is OFF.
It's not *quite* that simple. L1/L2 charging requires a computer 'information exchange' between the EVSE and the onboard charger. The EVSE sends a square wave of a certain amplitude to the onboard charger so it can adjust it's charge current to whatever the EVSE says it can provide and it's not until this message has been received and replied to that the relays are closed and charging can begin

I don't know a darned thing about L3 charging, but since it's being done at currents which nearly have the capability to destroy the battery, I would *bet* that the car has complete control over this process and the car must be in constant communication with, and in control of the external charger - That's probably why we see so many more communication pins on the L3 port than we have on the L1/L2 port. If the battery begins to get too warm, or the voltage begins to get too high, the car must be able to reduce the charge current, and/or cancel the session all together. Unless every iMiEV comes already set up do this, then retrofitting the L3 charging capability to a car that didn't come with it is going to be very difficult and expensive to do

Don
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PV1
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Re: Add DC quick charger?

Sat Mar 23, 2013 12:46 pm

Perhaps I wasn't too clear. What I meant by +12 volts and -12 volts was the coil voltage applied to engage the charging contactor (we seem to agree there's just 1 charging contactor, right?), and that contactor decides where battery voltage goes to, J1772 charger or CHAdeMO port. I would think communications would have full-time connection from the port to the car. I completely understand how CHAdeMO communications are much more than what J1772 is, I was just discussing how the car may be set up on just battery voltage in the charging system since a single, on/off contactor is not all that controls battery voltage on the charging side (as evidenced by 0 volts on the CHAdeMO port during L1 charging). My post wasn't really involving communication connections at all.

I hope this makes some sense.
"Bear" - 2012 Diamond White Pearl ES with QC - 2/21/2013
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Don
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Re: Add DC quick charger?

Sat Mar 23, 2013 2:21 pm

Sure - What you're saying makes sense to me. My point was . . . . until/unless someone figures out if every iMiEV ever made comes with everything needed to control the L3 charging process (even those cars which didn't come with the external hardware) then isn't it premature to buy a bunch of expensive ports and relays and install them only to find out that the car doesn't have everything needed to control the process?

Surely nobody is actually contemplating just buying the hardware and trying to stick 330 volts @ 50 or 75 amps in the port without the car having the computer hardware/software and the BMS necessary to control the process and protect their $10K+ battery . . . . or are they? :shock:

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

PV1
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Re: Add DC quick charger?

Sat Mar 23, 2013 8:11 pm

Oh, sure. That's makes sense. The problem is, the only way we may ever find out is if someone installs the wiring and plugs the car into a quick charger.

Maybe the flooded raspberry MiEV owner could shed some light, but that all depends on if it has the quick charge port option or not.
"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

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jray3
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Re: Add DC quick charger?

Mon Mar 25, 2013 11:41 am

PV1 wrote:Maybe the flooded raspberry MiEV owner could shed some light, but that all depends on if it has the quick charge port option or not.


Yes, Ben has agreed to share more photos of the HVDC connections and contactor on his raspberry i-MiEV, but he's been pretty quiet for the past month. It did have CHAdeMO, and I have dibs on that hardware! ;) You can see him removing the HVDC cable connections in his YouTube videos, but it didn't show the contactor.
http://www.youtube.com/watch?v=7KhGJNn4 ... g&index=17
Thanks for checking the CHAdeMO pin voltage, PV1. That wouldn've been too simple an answer, but was worth checking.
A DPDT HV contactor is one possibility to explain the single contactor. I've never seen one- though I do have a monster DPDT for motor reversing.

Don, no I wouldn't put 50 kW into a retrofitted ChAdeMO port right off, as I only have control of 4.8 kw at 330 VDC, and the uncontrolled jumper cable "DUMP CHARGE" technique using Andersen PowerPole 350's is not for the faint of heart.
But I have pulled up to 22 kW out of the Range Trailer while feeding the Karmann Eclectric between races!
http://www.facebook.com/pages/The-Range ... ref=stream
(It's got 200 AH at 360V of ThunderSky cells feeding a Manzanita PFC75 charger.)

Provided that the i-MiEV is turned on and charging current is input upstream of the current sensor, is appears that the car couldn't tell the difference between heavy regen and an offboard current source, and would accept it normally, though not be able to cut it back automatically. (Unless that meddlesome little silicon brain is also looking at motor speed, wheel rpm, selected drive mode, or a dozen possible other conflicting inputs.) I won't hook my i up to HVDC of any flavor until after much more research!
Last edited by jray3 on Mon Mar 25, 2013 4:54 pm, edited 1 time in total.
2012 i-SE "MR BEAN" 70,000 miles
i-ES traded at 21,648 miles
2000 Honda Odyssey
1987 F250 Diesel
1983 Grumman Kurbwatt,170 kW, 32 kWh
1983 Mazda RX-7 EV 43 kW 10 kWh
1971 "Karmann Eclectric" EV 240 kW 19 kWh
1965 Karmann Ghia Cabriolet

Don
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Re: Add DC quick charger?

Mon Mar 25, 2013 12:08 pm

Since commercial CHAdeMO stations are capable of recharging many different makes of cars with many different battery packs, I would suspect it's up to the car to tell the charger exactly what it wants/needs - Whether it's 330 volts, 335, 340, 345 or whatever voltage suits the pack being recharged. I would guess that it would require a very precise control of the charge voltage (the ability of the car to move it up or down to get it just right) in order to make the pack draw the correct amount of current. The commercial stations must be looking for those control signals from the car in order to 'reply' and get the charging process started. From the number of pins on the quick charge connector, I suspect it's looking at lots of variables, sending many real time signals to the charge station and micro-controlling it during the entire process - From the chart above, it looks like it checks the charge current and makes the necessary adjustments every 100ms

For your home-made 'quick charging station', I just don't picture applying some arbitrarily chosen voltage (330, 335, 340 volts? . . . . who knows?) directly to the pack without any control from the car as being a good idea for the life of your $10K battery pack. Even our puny little 3300 watt, 10 amp onboard charger is under complete computer control at all times. I've got my fingers crossed for your 'trials' and hope it works out OK for you . . . . but you're certainly a bolder man that I ;)

I just picture this whole quick charging process as being a bit more complicated than you seem to think it is - I certainly believe it's LOTS more complicated than the normal onboard recharging system, and even that relatively simple process seems too complicated to me to fiddle around with

Good Luck!! . . . . but keep your fire extinguisher handy just in case!! :shock:

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

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