PV1
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Re: Wrecked i-MiEV Battery Pack Discussion

Thu Apr 28, 2016 6:56 am

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I count 5 contactors. Each contactor has two lugs on it (upper and lower).

1. Top Left - QC Negative Contactor
2. Top Center - QC Positive Contactor
3. Bottom Left - Main Negative Contactor
4. Bottom Center - Main Positive Contactor
5. Bottom Right - Main Pre-charge Contactor

The L shaped bus bar in the middle right connecting the upper lug of contactors 4 and 5 and the lower lug of contactor 2 is Battery Positive (Caution, live voltage present on this bus). The other bus bar to the left, which connects the upper lug of contactor 3 and the lower lug of contactor 1 is the Battery Negative.

The bus bars connected to the upper lugs of contactors 1 and 2 go to the QC port connectors on the outside of the pack.

The bus bars connected to the lower lugs of contactors 3 and 4 go to the main HV connectors on the outside of the pack (where the wires from the MCU connect). The wire connected to the lower lug of contactor 5 goes through a pre-charge resistor, which terminates on the Main Positive bus bar (the wire below contactor 4).

I'm not absolutely certain on this configuration, but it aligns with what I've read in the Technical Information Manual about how the car's HV system functions.

The construction of the case seems over-complicated compared to other packs I've seen. Tesla's pack is a work of art.
"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.

jray3
Posts: 1500
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Location: Tacoma area, WA
Contact: Website

Re: Wrecked i-MiEV Battery Pack Discussion

Fri Apr 29, 2016 8:57 am

Thanks, it's great to finally have a visual of what's been long-discussed! Those two QC contactors would be key to charging with an offboard charger, or using a secondary battery pack for range extension. For a secondary pack, a second i-MiEV pack would certainly do, but any lithium battery with a couple more cells than ours should work by fully discharging itself first, so that we can then disengage the auxiliary pack and have a full main battery. (though we'd have little to no regen when using an aux battery with slightly higher nominal voltage). It shouldn't be hard to manually engage the QC contactors, bypassing all the CHAdeMO chatter, and if the car is in "READY" when you do so, the BMS and associated Coulomb counting would keep the original pack happy. The only unknowns I'm concerned about would be error codes or a shutdown from the nanny systems, but it sounded like success when siai47 did it.
2012 i-SE "MR BEAN" 87,000 miles
2012 i-ES traded at 21,648 miles
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

kiev
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Location: The Heart o' Dixie
Contact: Website

Re: Wrecked i-MiEV Battery Pack Discussion

Sun May 01, 2016 8:54 am

Would you be able to get a part number of the main contactors?

They look similar to these from Omron

400V,200A Relay
kiev = kenny's innovative electric vehicle

Dani

Re: Wrecked i-MiEV Battery Pack Discussion

Fri May 06, 2016 4:15 pm

Main contactor:

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Here's the chademo contactor:

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So we got to work a step further by loosing the packs.

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disconnected the wires for the cell-BMS-boards

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And prepared the cells for removal from the frame:

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We found how attaching a solid piece of steel at the outer end of the 5xLEV50-8 we would have all of the 5 packs fixed at both ends. This due to the LEV50-8 packs already being fixed together on the side towards the center of the frame. Sure lifting 75kg of batteries (5xLEV50-8) is unhandy however having a piece tying them together could work in keeping the cells in place and reuse the buss bars. Just taking the cells out of the plastic bay and out of the securing fixing points of the bay causes the LEV50-8 cells to twist and breaks the buss bars if lifted up all together. We put a piece of wood below as additional support in preparation for removing them from the battery frame.

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Taking a look at where best to connect the HV wiring on the car as considering a solution via the chademo inlet.
I took out the plastic cover surrounding the wheel below the chademo inlet.

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The brown'ish colour covering the ducting and others will be rust-protection.

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So I am looking for options of how to tap in on the Chademo HV wires. Looking to where there could be space to fit the contactor and HV wires coming from the 2nd pack.

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To get more space I took out the inlet:

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And checked for any space on the inlet to fit a second set of HV wires for the 2nd pack.

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Obviously no extra space on the inlet terminals.

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Next I took a look behind the inlet area looking for space of where to fit a junction of the HV wires.

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http://i.imgur.com/XFhc4OB.jpg

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From this I'm seeing space behind the inlet if wanting to place the contactor or some kind of junction of the HV wires.

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I took out the chademo inlet by loosing the clips using a flat screwdriver.

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Next I worked on recovering wires from the wreck.
I want to reuse the HV wires and BMS wires. Regarding the BMS wiring I could use the electrical diagram over the circuits of which wires does what.

This will be the BMS and wiring on the wreck. I removed the A/C controller at the bottom to get a better overview.

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I've made an understanding how the right-hand yellow connector on the BMS is connecting the battery sensors. Anybody who can bring clarity to this? .. wiring diagram would be helpful.
On the left-hand yellow connector it seams there are a bunch of other stuff connected. I'm wondering what each of these wires do and which are needed for the BMS to keep balancing the battery pack. The intend is to have the 2nd BMS continuously balance the 2nd battery, without communicating to the ECU, unless the left-hand yellow connector is taken out of the 1st BMS and inserted into the 2nd BMS. Anybody who can clarify as to whether the left-hand yellow connector can be left out and still having a functional BMS?

Without the wiring diagram I followed up the wires from the left-hand yellow connector to figure out where they are going

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Blue and Grey are routed to the front of the car. The white seams routed directly to the ECU. The others looks less clear as they go in to those junction-connectors near the A/C controller.

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Input and comments are welcome.. and a wiring diagram. :)

This progress was made over 3 days. After a full day mostly underneath the car I got the BMS & ECU wires and connectors off.. Had to cut most of the ties to release the wires and to keep all the wires in one piece which was the aim. I also got the HV wires from the battery off as well.

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So next up is
- Clarity on BMS wires: What does the wires of the left connector do?
- Clarity on HV wires from 2nd battery via Chademo HV wires. How and Where?

To be continued.. :)

Dani

Re: Wrecked i-MiEV Battery Pack Discussion

Thu May 12, 2016 4:23 pm

So we pulled it off and got the second pack in the car and connected. Great job. It took lots of preparation and studying wiring diagrams.

In the last few days I studied the manual which I downloaded via this forum under the articles.
I found the diagrams of the BMU (BMS unit) and looked for how to hook up the second BMS from the wreck if possible without disturbing the ecu.

Summery of achievment at this point.
- The ev is now having 2 BMS installed and only one communicating to the ECU. The CAN signals can be switched on so one BMS transmits at a time. And it works - mostly. :)
- The ev has an additional contactor and fuse placed inside the cabin below the rear seats to the right (replaced the tire-fix). This is placed inside a box for increased safety.
- As trial the HV wiring is completed by unscrewing the chademo inlet, and plugging a chademo plug into the inlet. The wires from the Chademo plug are routed through ducting below the ev and up underneath the right hand side of the rear seats. At this location there's already a rubber seal which hosts another smaller 2-wire circuit. The chademo and HV wires are packed up tightly up and behind the left rear wheel cover/mud-guard.
- A complete set of wiring is pulled from the wrecked ev and placed underneath the metal covers of the rear seats. The used connectors and wires are sticking out: BMS, bms wiring, contactor, grounding, chademo relay..

.. and finally we got the second battery pack in the back of the car. Great job everybody. We were 3 guys placing each of the two main 5xLEV50-8 packs at each footwell in the back. They are support by a plate on the back side and leaning down on the "seats". The two LEV50-4 are placed in the center between the two main packs. This design placement worked out well with regards to lenght of the bms wires.

Starting up the EvBatMon or Canion, they are seamingly both able to connect to the main/stock battery below the ev. When flipping the switch which I put on the CAN wires along with two relays this makes the it possible to see the status on either battery, one at a time.

Before connecting the HV wires to the contactor and before even considering starting up the ev I used the monitoring app's to see the Voltage of the second battery pack, in order to match the same voltage by charging the main battery to same level of voltage. I reached a level of 0,3Volts apart and decided to try and connect the contactor and start up.

The ride back from the workshop was easy and indeed used little power.
Tests in time ahead will show more about range increase and other new discoveries.

Testing contactor after discovering how the ground-wire to the qc relay was actually activated from the ecu. This caused confusion at first as the QC contact in the main pack wouldnt engage nor the second contactor for the second battery. After more studying of the technical diagram I found which wire to access and so we got the contactors activated and access to the power of the main battery via this second contactor. Huge relief and celebration. :)

Measuring on the side of the contact connected to the Chademo inlet.
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So the contactor is connected in parallel to the main contactor in the battery pack which means this turns on and off as the car is put in "ready" and off.
Showing the Voltage of the main battery pack.
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Showing the contactor is indeed switched on.
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Then pulling the ev in to the workshop area and bringing the second battery ready as the preparations of contactor, bms wiring, bmu and CAN signal was complete.

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The contactor placed in box for safety. The fuse put directly on the contactor in this trial periode. When in regular use a more secure setup is needed.
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Batteries placed inside the car and HV wiring between the cell-packs was carried out.

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As the main battery had charged to similar Voltage levels as the second battery the HV wires on the second pack was connected to the contactor and contactor was disconnected. This offered the opportunity to have both voltages available on the contactor on either side ready to measure.

Voltage on the main battery below the car.
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Voltage on the second battery inside the cabin.
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OBD readings of the main battery status

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OBD readings of the second battery status

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Interestingly the Amps and kW seams negative. Unsure what to do about this. Any clue?

kiev
Posts: 659
Joined: Sun May 03, 2015 7:15 am
Location: The Heart o' Dixie
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Re: Wrecked i-MiEV Battery Pack Discussion

Thu May 12, 2016 7:23 pm

That is great progress, and thanks for sharing the pictures and details of how you were able to fit the pack into the back seat area.

i would guess that the second pack is entering the circuit in such a way that the current sensor is reading a reverse polarity with respect to the normal direction of current flow, and as a result it produces a negative value.

But there are no "negative" numbers in the digital world, only some sort of two's-complement interpretation of very small or very large values. The regular pack was showing 0.7 Amps, a very small value or nearly zero depending on what loads were active. The same loads were likely active with the second pack but the current sense was opposite direction, so -0.7 A. But the software would interpret this nearly zero negative value using the 2's-complement as a value at nearly full scale, and then set the negative direction bit (regen). The CanIon reads the CAN buss and reports 327.7 A in the regen direction, or the -327.7 that you saw. Power is calculated from VxI, so it is (-) also.

Assume 16-bits with one for direction, leaves 15 bits for value, so values range from 0 to 2^15 =32768 full scale, which reads as 327.7 with a scale factor of 10 mA per bit.

Something is definitely confused since it is showing a SOC of 122.5%...? what does that mean?

A simple schematic diagram of your arrangement might help understand what is happening.
kiev = kenny's innovative electric vehicle

Dani

Re: Wrecked i-MiEV Battery Pack Discussion

Fri May 13, 2016 3:21 pm

Brief update from first trial driving with 2 battery packs.

Driven 178km and CaniOn says 33% remaining on either battery.
Driving conditions: mix of aprox.
48km city trafic (0-50km/h),
100km main road (70-80km/h) and
30km of motorway (95-110km/h).
Temperatur: 15-20degC
Humidity: 55-65%
Altitude: 0-100m, with 5-10 climbs of 4-8%. Each about 500m.
Wind: 10-15 m/s headwind and tailwind on return.

PV1
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Re: Wrecked i-MiEV Battery Pack Discussion

Fri May 13, 2016 4:42 pm

Nice. Just about double the range, which is what one would expect. Quite interesting that you were able to get two BMUs to work with one car, but it makes sense (only one at a time with the same PIDs and data close enough to not cause a fault).

Out of curiosity, how much does the empty battery case weigh?
"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.

Easycarex
Posts: 33
Joined: Fri Jul 20, 2012 8:08 am

Re: Wrecked i-MiEV Battery Pack Discussion

Sun May 15, 2016 11:03 am

Well done!
Will you be selling the MCU from the crashed car?
Should know this week if it's stopping my Citroen C0 from coming to ready.

DonDakin
Posts: 376
Joined: Wed Aug 15, 2012 7:10 pm

Re: Wrecked i-MiEV Battery Pack Discussion

Sun May 15, 2016 3:11 pm

Hey Dani,

Congratulations on the great work and the photos. I assume you are charging the the 2nd pack with an external charger.

It looks to me if I understand you correctly that you are able to swap the BMS CAN signals from the internal and external pack and read the voltages from either pack. It's good to know that works. For the current I believe there are 2 current sensors somewhere I am not sure of the location.

I would guess that you are missing something that is generating the current value and putting it on the can bus for canion to pick up. I took a look at the diagrams I think you already know about this site:

http://mmc-manuals.ru/manuals/i-miev/on ... dex_M1.htm

I was not able to locate anything related to current sensing in there but I might have missed it. If the current sensor is working on the internal pack but not on the external one it might be some signal that is missing in the BMS connector or something missing downstream. If the CMU's also sense current and send it up to the BMU and maybe something is disconnected when you broke up the battery in sections. Did you see any current sensors in the battery ?

Maybe someone else on the forum knows where the current sensors are and how they send data.

What you are doing is really amazing. Please keep us up to date.

BTW

how does the car handle with the extra weight ? It looks like you are trying to get it as low as possible so it should be better then when sia47 did it.


Don.......

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