Add DC quick charger?

[jray3]

I would suspect it's up to the car... I would guess .. The commercial stations must be looking ...I suspect it's looking at lots of variables, ... it looks like it checks the charge current ..
Don

From what I've read, Don, you're correct on all of the above. BUT- I've yet to hear a reason why bulk fast-charging could not be performed on occasion with little or no ill effect, IF the operator takes care to stay within limits. The hobby and race-duty chargers like Manzanita Micro's do not apply an arbitrary voltage- they apply precisely what is programmed in terms of voltage, amperage, and hold time at constant voltage for a finishing charge (set to zero for bulk charging). We know that Mitsu went very conservative on our cell voltages, not providing a high-charge option for extended range.
http://www.gs-yuasa.com/us/technic/vol5/pdf/05_1_021.pdf
GS Yuasa tested these cells by charging to 4.10V in three hours. Mitsu has us charging to 3.955V in 6 to 21 hrs... (and provides no guidance on whether 21 hrs or 6 hrs makes any difference in battery longevity)
Exactly how much more energy could be stored with that extra 0.145 V is hard to tell, but the above-linked graph shows how flat the discharge curve is at high voltage, and makes 10 Ah or 20% look possible.
It's like we're forced into the 80% charge at all times without a boosted option for those heavy-duty days. Bottom line though, this is a warranted product, which much be "*****-proofed" to the greatest extent possible. Nissan was reminded of this by their hot climate customers (who received no warning from their cars that heat damage was occurring ).

Lastly, it appears to me from several sources that the length of spent at high state-of-charge has a greater effect on pack longevity than exactly how high the peak voltage is, yet I see no cars or EVSE pursuing that control strategy. (Bring SOC to a certain level, say 50% ASAP, then restart charging X minutes before a planned departure in order to minimize time at high SOC.) :? Of course, this would increase the importance of periodic balancing charges.

 

[Don]

Is your plan to build a quick charger, or are you more interested in charging to 4.1 volts per cell in order to gain a few extra miles of range?

GS Yuasa tested these cells by charging to 4.10V in three hours. Mitsu has us charging to 3.955V in 6 to 21 hrs... (and provides no guidance on whether 21 hrs or 6 hrs makes any difference in battery longevity)

I've changed my thinking on this after reading everything I could find over the past year regarding the care and feeding of lithiums and I suspect it really doesn't make much difference in their longevity. So long as you're charging at 0.5C or less (and some say as high as 0.7C) the cells really don't care, and our 3300 watt, 10 amp onboard charger is only capable of about 0.2C, so either a 6 or a 21 hour charge is really slow, relatively speaking. Even a 3 hour charge would still be less than 0.5C

Exactly how much more energy could be stored with that extra 0.145 V is hard to tell, but the above-linked graph shows how flat the discharge curve is at high voltage, and makes 10 Ah or 20% look possible.

True, but I wonder what the existing BMS attached to the battery would think when you try to recharge the cells above 3.9? - I'll bet our BMS isn't programmed to like that at all. The tests you refer to probably were not done with the current BMS setup active. I would imagine they either used no BMS at all for those tests, or one they had programmed for 4.1 volts

It's like we're forced into the 80% charge at all times without a boosted option for those heavy-duty days. Bottom line though, this is a warranted product, which much be "*****-proofed" to the greatest extent possible

Yes, we're forced into an everyday 80% charge and then if you're quick charging them, you get only 80% of that 80% . . . . and even then, they recommend you not do it everyday. I think quick charging is done at about 2C (100 amps) isn't it?

I'd feel lots better about the whole idea if we had the SCiB cells which were specifically created with the idea of quick charging them

At any rate, your experiments will be a real learning process - I'm sure you'll keep us posted on how it goes and what you find

Don

 

[jray3]

Thank You Don,
I'd most prefer to add CHAdeMO in the OEM configuration, as there are enough stations around Seattle now to make it worthwhile (I can't get home from Seattle without a 3 hr charge). Also, as I've managed EVSE installations in my day job, I find myself acting as liason between the Seattle EV Assoc and Ecotality on getting more BLINK DCQC deployed.

Exporting HVDC from the iMiEV is another big motivation in pursuing an unconventional setup. As an EV Drag Racer, I'd love to have the ability to pull 16 kW from my iMiEV to top off a car at the track, and also the ability to hook up my big UPS unit (designed aroud a 240V battery) to power the house during a blackout.

Having the Manzanita Micro charger (which can also operate as a DC-DC converter) in Karmann Eclectric means that I already have most of what's needed for DCFC in my garage. Imagine the stock charger pumping into the pack while the pack also receives 20A a through the Karmann or from the wall. I already simultaneously pull 16A and 20A from the wall when charging both cars, and the house's 200A service handles it just fine without adjusting other loads. That would allow an 8.1 kW charge rate for the iMiEV, theoretically bringing the pack from 0% to 80% in 95 minutes. Again, it's not a real 'need', but would increase utility of the car.

And then there are those rare days, like heading up to Mt. Rainier, where an overcharge could make the difference between using the iMiEV and taking a gasser. HowEVer, my pusher trailer project still has top priority, as it offers much more than even a 20% range boost from overcharging and would not involve any hacks to OEM systems. A lot of this may wind up being a thought exercise, but I'm learning stuff and not spending much (yet). As the wife says, she'd rather be a 'garage widow' than a 'bar widow'. :roll:

 

[Don]

You're married to a wise lady

I like the idea of your pusher trailer, since it leaves the car stock (thus not tampering with the warranty) and is only used on an 'as needed' basis . . . . plus, you can use it on more than one car, which is a really big advantage for you

Don

 

[jray3]

Exactly how much more energy could be stored with that extra 0.145 V is hard to tell, but the above-linked graph shows how flat the discharge curve is at high voltage, and makes 10 Ah or 20% look possible.

True, but I wonder what the existing BMS attached to the battery would think when you try to recharge the cells above 3.9? - I'll bet our BMS isn't programmed to like that at all. The tests you refer to probably were not done with the current BMS setup active. I would imagine they either used no BMS at all for those tests, or one they had programmed for 4.1 volts

Yes, and depending on the design of our BMS, it would either start burning up current through a shunt as the voltage rose, or command the contactor to open (probably once all BMS modules signaled high V).

It's like we're forced into the 80% charge at all times without a boosted option for those heavy-duty days. Bottom line though, this is a warranted product, which much be "*****-proofed" to the greatest extent possible

Yes, we're forced into an everyday 80% charge and then if you're quick charging them, you get only 80% of that 80% . . . . and even then, they recommend you not do it everyday. I think quick charging is done at about 2C (100 amps) isn't it?
Don

I'm pretty sure that the Aerovironment and Blink DCQC installed along I-5 thus far are limited to 50 kW, and they have been logged at averaging only 30 kW into a LEAF.

 

[Don]

Some interesting facts about the pack

"Mitsubishi tested the cycle life of the pack under standard (50 A) and quick charge (120 A) conditions using the JC08 driving pattern and found that the pack retained 84% of capacity with quick charging and 83% with standard charging after 1,000 cycles."

Mitsu considered a 'standard' charge rate of 1C and even that doesn't seem hard on the pack - Our L2 Max charge rate of about 0.2C appears to be little more than a 'trickle' charge by comparison. Safe to say there will be very little difference in pack lifespan whether we recharge with 120V @ 8 amps or 240 volts @ 14 amps . . . . either is relatively tiny by comparison

Also interesting is they report the same (slightly better actually) lifespan using a 120 amp (2.4C) Quick Charge

Lastly, their test results are for a period of only 1,000 cycles, which is less than 3 years usage for some of you guys - We'll be delving into relatively unknown territory here before too long . . . . at least, some of you will

Don

 

[nsps]

Also interesting is they report the same (slightly better actually) lifespan using a 120 amp (2.4C) Quick Charge

Yes, I found that quite surprising since the manual actively discourages frequent use of Quick Charge.

 

[peterdambier]

Regen switched off when battery is full.

I have seen the question earlier and can confirm - leaving home with charged battery, climbing over the hill and rolling down the other side, regen gets reduced half way down and finally cuts off before I reach the bottom - except when the heater is on. The BMU is watching and talking to the motor controller and to the CHAdeMO charger.

Concerning electricity germany is a third world country. Many of our households have 3 phase 35A each. Some have 25A single phase. We can do L2 at home but that is it. There is a 20kW charger for us nevertheless:

http://www.e8energy.de/produkte/strom_ladestationen/49,[email protected]

They can charge from 400V/32A 20kW or 400V/16A 10kW using CHAdeMO and I know they have been experimenting with some 650V DC from solar arrays. I have learned from the evtv.me forum the Lithium Iron Phosphates love quick charging but the'll explode from trickle charging. There is no doubt 80% quick charging is better for long live than regular charging 100% is.

 

[JoeS]

Concerning electricity germany is a third world country. Many of our households have 3 phase 35A each. Some have 25A single phase. We can do L2 at home but that is it.... I have learned from the evtv.me forum the Lithium Iron Phosphates love quick charging but the'll explode from trickle charging...

Peter, I think you're short-changing your country as Germany's use of solar/wind to displace fossil fuels is showing the world that it can be done on a large scale. Now, it's just a matter of upgrading each home's electrical capacity… (I know, I know, easier said than done).

As much as I like their topics, I long ago gave up sitting through evtv's ramblings. I had never heard of any issues regarding slow charging of any type of Lithiums. This was confirmed a couple of years ago at a presentation at our local electric auto association meeting when I point blank asked the chief scientist of a Lithium battery development startup if there were any problems charging too slowly? - The answer was NO. Since I primarily charge using L1, do you happen to recall which episode of evtv this assertion was made (or did the assertion pertain to really minute unregulated input trickle currents)?

Back on topic, I too would be interested in adding CHAdeMO to my Mitsi, although so far for over a year L1/L2 has been more than sufficient for our daily drives.

 

[peterdambier]

Not only the video but the blog as well.

http://blog.evtv.me/2012/10/charge-fast-die-young-leave-a-great-looking-car/

Next more on CHAdeMO is

http://blog.evtv.me/2013/01/2066/

From those two it looks to me like CHAdeMO will make it. There are already hackers trying to reengineer the CANBUS data exchange and the hardware is open. For SAE you have to buy a bugged (property crippled) computer to read the documents and swear not to leak any of the information in the unreadable documents.

May be I am a bit discouraged with our electricity mess in germany but on the other hand we are very close to completely autonomous households not even connected to the mains.

In our county I am spreading the idea of factory outlets for electricity so people can bring their batteries (i-MiEVS) and get their power without feeding networks and bureaucracy for one third of the price. Imagine we are paying 33 cents per kilowatt hour. Dollar cents and Euro cents are close enough to compare. Gas is expensive but they try their best to "keep electricity competitive".

Trouble is we dont have enough capacity in the wires and 3-phase does not save us. The future will be DC and I guess DC charging will get its own grid.

 

[aarond12]

The future will be DC and I guess DC charging will get its own grid.

That's a fundamental problem with DC: It doesn't travel well over long wires/distances. AC does, which is why the world's grid is AC. If a DC "grid" ever materializes, it will be multiple small charging points... exactly like Tesla's SuperCharger network. If we can get a CHAdeMO network like the SuperCharger network, then we're golden... or at least the i-MiEV owners who have DC quick chargers. (Sadly, not me.)

 

[RobertC]

On i-MiEV's with the Quick Charge Option there is a 12V Quick Charge Relay located under the back seat. This relay is not installed on i-MiEV's without the Quick Charge Option. There are two high voltage contactors located in the Traction Battery. Both contactors switch both the plus and minus terminals of the Traction Battery. The Main Contactor connects the Traction Battery to the Inverter and is controlled by the EV-ECU. The Quick Charge Contactor connects the Traction Battery to the Quick Charge Port and is controlled by the Quick Charge Relay. I cannot tell if the Quick Charge Contactor is installed in i-MiEV models without the Quick Charge Option without removing and examining the Traction Battery.

 

[Don]

The future will be DC and I guess DC charging will get its own grid.

That's a fundamental problem with DC: It doesn't travel well over long wires/distances. AC does, which is why the world's grid is AC.

Yes, George Westinghouse nearly put Thomas Edison out of business due to this fact

Don

 

[JoeS]

Not only the video but the blog as well. http://blog.evtv.me/2012/10/charge-fast-die-young-leave-a-great-looking-car/

Peter, thank you for this link. Good discussion on charging in the blog, but I haven't yet taken the time to sit through that EVTV video. Was happy to see them praising the PowerLab8 (I have two which I use extensively for all my Lithium charging and experiments). The blog provided some explanation of the 80% SOC usually associated with QC. I especially liked the discussion of possibly using the PulsaR for converting solar into direct traction battery charging or for taking stored energy from a large standby battery bank and dumping it into the car's traction pack. This has certainly given me some ideas for my other EVs (or the iMiEV, after the warranty runs out).

Regarding the supposed damage to the LiFePO4 cell during low current charging it was unclear what the conditions were for this to have happened; in any case, the message was clear: shut off charging when the current input drops to 0.05C and do not continue stuffing current into the cell even though the voltage is held constant.

To stay on-topic, I appreciate the various bits of information everyone is providing about adding CHAdeMO to the iMiEV.

 

[RobertC]

The following picture shows the latch and Quick Charge Port for i-MiEVs with and without DC Quick Charge.

Access to the cable to unlatch an i-MiEV Quick Charge Port door on vehicles without the Quick Charge Option can be found by taking off the cover inside the back right of the car.
If you are a hippie, this is probably a good place to hide your stash. I can get my whole arm in there.

The next picture shows the Quick Charge Relay and Junction Connector 5 on an i-MiEV with and without the Quick Charge Option (located under the back seat - driver's side). Notice that there are more wires going to J/C 5 than on the non Quick Charge i-MiEV.
The Quick Charge Relay controls the Quick Charge Contactor located in the battery pack. I'm not sure if i-MiEV's not equipped with the Quick Charge Option have the Quick Charge Contactor.

 

[acensor]

I like the idea of your pusher trailer, since it leaves the car stock (thus not tampering with the warranty) and is only used on an 'as needed' basis . . . . plus, you can use it on more than one car, which is a really big advantage for you...
Don

I missed the pusher trailer idea.
Was/is that a Trailer with an extra battery pack? Did you know someone....can't remember who/where...is considering something like that as Rental business ?
You'd plug it in hitch it up and rent it only that two days you wanted to drive 200 miles per charge.

 

[jray3]

I missed the pusher trailer idea.

Hi Censor,
'tis I who is pushing the Pusher Trailer idea. Here are my blog posts dealing with the project.
http://karmanneclectric.blogspot.com/search?q=pusher

In short, a pusher trailer is a range extension trailer that mechanically pushes on the tow vehicle. A battery or generator trailer are different strategies for range extenders. I'm builiding my pusher from an aircooled VW drivetrain, mainly out of dedication to my first love...

 

[GdB]

I just purchased a perfect condition 2012 i-Miev that compliments my 2002 Golf TDI for all our (wife and I) driving needs. Most of my driving is city traffic now that I can justify and enjoy more the shorter slightly congested city traffic route instead of the longer often also congested freeway I took with my Golf TDI.

My i-Miev came with premium SE package interior but unfortunately no L3 charger, so I am watching this thread and encourage those who started this process to finish. Whatever I can do to help, I'm an engineer...

Still waiting to be able to post a picture

The only thing I’m not happy with is the handling not nearly as good as my Golf TDI. To that end I looked at some tire upgrade options, and noticed there is a lot to read on this thread http://myimiev.com/forum/viewtopic.php?f=26&t=1656&hilit=front+tire+options.

 

[FiddlerJohn]

I just purchased ... premium SE package ... but unfortunately no L3 charger ...

GdB. Does you i-MiEV have GPS?
The GPS and the L3 CHAdeMO port comes with the premium package. In 2012 there were three main model options: ES, SE, and premium package SE. Are you saying you have the SE without the premium package?

Probably siai47 is the only person to successfully add a CHAdeMO port to an i-MiEV.

Success! At least the first part is done. I got the pack from the wrecked car installed in the new car---turned the key and everything worked with no warning lights. The battery fan cycled for the first time. Runs and drives fine---got to find a QC station to try out the QC. To confirm what Don said, you would have at least three thousand dollars or more in parts alone to just add the QC components--probably much more. The short list would be battery fan, harness and mount; two heater floor ducts and pack connector; two high voltage contactors with associated harnesses and buss bar; main motor wiring harness (that alone is just over a thousand dollars per the dealer); Chademo connector and associated harness; release handle and cable for the QC port door; new (or recalibrated) BMU; various low voltage relays, connectors and brackets. In addition the carpet needs to be modified to clear the floor duct and you have to have a desire to cut a 3" hole in the floor of your new car and hope you got it in the right place. Finally you need to add the labor costs to do all this. Fortunately a bored retired dude didn't charge himself for that! Unless there is a donor car available this won't work.

 

[GdB]

No GPS, BT... I must be mistaken, I have SE but maybe not premium. But my wife says the seats are much nicer than base.