Hello.

I have a 2005 Civic IMA which is now at 197k km. The IMA battery was replaced in 2011 at about 110k km and has worked flawlesly (never seen a recal) until last month. I was driving down a pretty steep 15km hill. When I reached the bottom engine and IMA lights came on and the charge gauge showed 1 bar (even though that the battery was completely full considering the long downhill) and tried to recalibrate, but never succeeded. The OBD2 codes were P1600 and P1433 at the time.

1)
I read tons of threads around this forum and decided that I will try to fix every stick separately. I disassembled the pack and on first cycle discharged every stick to 1V/cell, and in second cycle to 0.8V/cell (at appropriate current low current of course). Most of the sticks were then able to be charged to more than 6000mAh. Those that weren't reaching at least 6000mAh of charge, I then cycled them to 0.6V/cell. After that all sticks were able to be charged at least 6000mAh.

I assembled the pack and put it back in the car, but the problem wasn't fixed. I was then getting codes P1600, P1446 and P1443 (not always the same, sometimes only 2 of those), so I decided to try with grid charging.

2)
I built myself a dumb grid charger using two APC-35-350 in series (with appropriate fuse and diode protection). I grid charged for about 14h (with proper cooling) and the peak voltage that the pack reached was 171V. Then it started slowly decreasing to 170.1V. I unpluged the grid charger and let the pack rest for about a day. Then I plugged it on grid charger again for about 6h and the voltage raised to 170.1V where it stayed for a few hours. I put the pack in the car then, but the problem was exactly the same (same codes being thrown, I tried resetting the computer by unplugging 12V battery several times).

When I start the car it initially starts charging, but when the 1 bar shows it simply stops (appears that IMA system gets completely disabled at the car never tries to charge the battery until you restart the engine) and throws OBD codes. Otherwise the car is working normally, 12V battery is also being charged all the time.


I kinda ran out of ideas, how could I fix this? I don't understand why exactly the same codes are being thrown after a grid charging. When I worked on every stick separately, none of them showed any weird signs. Yes, some of the sticks self-discharge faster, but considering that the time between being unplugged from grid charger and trying the pack in the car is less than 30min, I can't imagine that the pack could already go out of balance.
It also seems that I also got rid of voltage depression in those sticks that had it (some of them held more than 1000mAh between 1V and 0.8V/cell).


I would really appreciate any idea, what else can I try. I have already spent more than one month working on this and kinda irritated by it already.

 

P1600 is "IMA fault on IMA side of things"
P1433 is Battery Module Deterioration
P1446 is Battery Module Individual Voltage Input Deviation (dead cell, or you screwed up the assembly)
P1443 is High Voltage Contactor/Bypass Contactor Stays Activated (Frequently intermittent, particularly if there's a battery issue).

Given the nature of your battery issues, i.e., failure without warning, that almost guarantees a CELL failure.

Questions

1. What were the 20 stick voltages as-removed?
2. In case you didn't read #1 correctly, and you're thinking of answering with "all sticks were within X range" that doesn't answer the question. Looking for 20 voltages.
3. When you recorded those voltages, how long had it been since it ran?
4. Since charge capacity is essentially irrelevant, what were your final discharge capacities for all 20 sticks?
5. What was your discharge current?
6. How did you quantitatively assess internal resistance?
7. How did you quantitatively assess self-discharge?

If you can't answer all 6 questions (2 is just a clarification) in a positive manner, i.e., with hard data, then you're effort is incomplete.

Check the BCM connector:

You simply probe the connector as it's plugged in. You need to measure between the pins in accordance with the picture.

vbh0 to vbh1
vbh1 to vbh 2, etc.

You'll have 10 voltages. Report all 10.

EDIT: to simplify, here are the pairings based on just the pin numbers (can ignore the VHBXX stuff):

14-6
6-13
13-5
5-4
1-7
7-2
2-8
8-3
3-9
9-10

You likely had a dead cell at the outset and failed to recognize it.

 

1. You mean the voltages of sticks when I disassembled the pack for the first time?
They were (from 1 to 20):
7,75
7,79
7,8
7,72
7,78
7,87
7,78
7,78
7,77
7,81
7,79
7,89
7,84
7,78
7,75
7,72
7,75
7,77
7,83
7,87

3. The engine and IMA lights turned on on 12th July, and I recorded these voltages between 18th and 23rd July (when I was doing the first cycle of my process).
4. Discharge capacities are 4200-4500mAh.
5. I used 5A to 1V/cell (where I recorded discharge capacity). When going to 0.8V/cell I used 1A and for 0.6V/cell I used 0.5A.
6. I guess I did not. My shows internal resistance, but I didn't note it down unfortunately.
7. When I discharged them in the next cycle approximately one week later, the charge lost was from 20% and up to 50%.

I don't understand what you mean with "as it's plugged in". I guess I have to stick multimeter in connector's pins, so what has to be plugged in then?

Thanks again for your time!

 

1. You mean the voltages of sticks when I disassembled the pack for the first time?
They were (from 1 to 20):
7,75
7,79
7,8
7,72
7,78
7,87
7,78
7,78
7,77
7,81
7,79
7,89
7,84
7,78
7,75
7,72
7,75
7,77
7,83
7,87

3. The engine and IMA lights turned on on 12th July, and I recorded these voltages between 18th and 23rd July (when I was doing the first cycle of my process).
4. Discharge capacities are 4200-4500mAh.
5. I used 5A to 1V/cell (where I recorded discharge capacity). When going to 0.8V/cell I used 1A and for 0.6V/cell I used 0.5A.
6. I guess I did not. My shows internal resistance, but I didn't note it down unfortunately.
7. When I discharged them in the next cycle approximately one week later, the charge lost was from 20% and up to 50%.

Readings from the BCM connector are:
0-1: 15.79V
1-2: 15.76V
2-3: 15.78V
3-4: 15.82V
4-5: 0V
5-6: 15.76V
6-7: 15.74V
7-8: 15.76V
8-9: 15.76V
9-10: 15.76V
10-11: 15.79V

 

To your credit, you've done more than most. Congrats.

Concerning #1: Yes, the first time you measured a voltage on the sticks BEFORE you did any charge/discharge operations.
Concerning #4: Did you discharge the sticks in the as-removed condition?
Concerning #5: What charger?
Concerning #6: Given the information thus far, this may be a big factor. If the IR on one of your sticks has gone high, and they can fail that way, The car is seeing voltage spikes during the initial charging. That can set a code. Testing at 5A isn't going to make high IR particularly obvious.
Concerning #7: I don't like ranges. Did you record them? The fact that you have a 20-50% variation in retained charge over the course of 7 days means your pack is shot. Even if you can resolve this issue, frequent grid charging is in this pack's future

If you recorded any data via google sheets, excel or anything, I might be able to see something in it.

Lastly, there's a chance there's nothing wrong with your sticks. They're not in good shape at all, but it's possible they're all working acceptably. I don't expect this, but I can't eliminate it without seeing the test data. Did you check the big fuse on the pack (100A) for continuity/resistance?

 

Here is my excel sheet: https://1drv.ms/x/s!Av83WakQvY_dlWBFVXne4C_QNq5L

#1: Those are the right numbers then (before I did anything with the sticks).
#4: I thought you meant the discharge capacities that sticks actually provide, if I discharge them soon after charging (so self discharge is not noticable)? Or you meant discharge capacities on my initial discharge? Anyway, please find all available data in the provided sheet.
#5: I have a SkyRC T6200.
#6: How can I test for this? My charger also displays battery resistance, but I didn't take a note of it for every stick. I read in the other thread that you suggested getting that 100A battery tester and doing 30s test with it.
#7: Please find all available information in the sheet.

I read in the other thread that someone had a problem with a that fuse, but I forgot to check it before installing the pack. I will try to do that test without removing the pack again (there's very little space unfortunately) in the evening.


What bothers me is that this malfunction happened so suddenly. Other people usually write about getting recals and stuff, but I haven't had a single recal or any other indication of the pack going worse. Is it possible that something just got broken during that long and steep downhill drive which I described in the first post)?

 

Here is my excel sheet: https://1drv.ms/x/s!Av83WakQvY_dlWBFVXne4C_QNq5L

#1: Those are the right numbers then (before I did anything with the sticks).
#4: I thought you meant the discharge capacities that sticks actually provide, if I discharge them soon after charging (so self discharge is not noticable)? Or you meant discharge capacities on my initial discharge? Anyway, please find all available data in the provided sheet.
#5: I have a SkyRC T6200.
#6: How can I test for this? My charger also displays battery resistance, but I didn't take a note of it for every stick. I read in the other thread that you suggested getting that 100A battery tester and doing 30s test with it.
#7: Please find all available information in the sheet.

I read in the other thread that someone had a problem with a that fuse, but I forgot to check it before installing the pack. I will try to do that test without removing the pack again (there's very little space unfortunately) in the evening.


What bothers me is that this malfunction happened so suddenly. Other people usually write about getting recals and stuff, but I haven't had a single recal or any other indication of the pack going worse. Is it possible that something just got broken during that long and steep downhill drive which I described in the first post)?

 

Your pack looks like a crime scene.

You don't have a choice. You need to pull the pack again. You've barely started the process.

Here's my recommendation (all testing to be conducted near 24°C):

1) remove pack
2) charge pack using your APC-35-350 "grid charger". Insure you are moving air through the pack. You should be able to feel the discharge air moving and measure it's temperature.
3) terminate charging the sooner of 1) 24 hours, 2) constant voltage for 8 hours), 3) 2V drop accompanied by increased output temperature > 37°C.
4) Given the metric system, I'm assuming you're on 220VAC. Get TWO 60W incandescent bulbs and wire them in parallel. Discharge the pack to 96V.
5) Repeat charge per #2 & #3 EXCEPT do not charge for less than 20 hours UNLESS pack output temperature exceeds 37°C.
6) Repeat discharge to 60V
7) Repeat charge per #5
8) Repeat discharge to 60V
9) Repeat charge per #5 EXCEPT allow up to 30 hours maximum.
10) Break down pack
11) Let sticks rest 7 days.
12) Record voltage and IR
13) Affix the aluminum spacers on to the stick ends with the long bolts, clamp onto the spacers and conduct 15 sec load test with 100A/12V battery tester, record stick voltage on separately attached meter (same meter as used in #12, or one that reads within 0.01V) immediately before terminating load. Allow tester to rest 2 minutes in forced air between tests (gives you enough time to move the spacers from stick to stick).
14) Discharge to 6V at 1A and record capacity

Once you have the above data, we can identify the bad sticks.

NEVER EVER charge the pack in-car unless the IPU lid is on, and you can control the battery fan with a PWM controller.

Here are some questions/comments concerning the data in the sheet:

1) Where is the initial discharge for stick 10?
2) Why did only a few get a 4th discharge?
3) 5 and 6mV -dV settings are too high. If you used alligator clips without additional precations, you may have shot yourself in the foot. Best to use ring terminals secured with bolts.
4) Did you monitor stick temperature during charge and provide at least some cooling?
5) If so, did any sticks exceed 40°C?
6) It appears that you have used charge capacity as the sole criteria. It means absolutely nothing. -dV charge termination is somewhat unreliable to begin with, it can vary by 10-20%, and it is very sensitive to connection quality. Typical banana plugs and alligator clips are your worst option.

Given #6, comparing your charge input to your discharge output is meaningless.

Even if you just failed to record it, stick 10 looks like total garbage. Many don't look much better.

If all you have are the 4mm banana plugs and alligator clips (I can't tell what kind the SkyRC unit uses, and I don't want to read the manual), you can compensate by using a zip tie around both banana plugs to squeeze them towards one another. This will ensure the contact between the banana plug and the socket is consistent. For alligator clips, thread the bolts into the end of the sticks, attach the clips to the threads and then finger tighten the bolt so the alligator clip is squeezed between the bolt head and the stick end. No need to deform the clip. The goal is to have the flat SIDE of the clip pressed into the stick end face thus providing more surface contact and a more consistent/lower resistance connection.

With this process, you're looking for outliers. Right now, your sticks show no consistency, or at least nothing consistent with a pack that may function properly.

Concerning the abruptness of the failure, that's pretty typical for an unrepairable pack due to a failed cell that can't be reconditioned.

Cells fail in 4 ways:
1) short - won't hold voltage
2) capacity loss - can't hold enough capacity to function as needed
3) self-discharge - loses charge faster than the rest of the pack to the point that the pack eventually sees it as #1.
4) high resistance - internal breakdown of the cell that may include loss of electrolyte that prohibits the cell from delivering or receiving the current required/provided by the car within the acceptable voltage limits.

At this point, it looks like you're dealing with #2, 3 or 4 on stick 10.

Any stick that has a 5A to 6V discharge capacity of LESS than 4000mAh is suspect. Variation within a pack > 10% is likely a sign of a failed outlier.

 

Thanks for the extensive reply. I will get down to business next week (need to gather needed tools and also I need a car for the next few days - not really comfortable driving around with 12V being charged only in limited range).

Now to the responses:
You are right, I'm from Europe. The voltage is 230VAC here (just tested at the outlet).

Just to make sure that I understand correctly, I make this discharge of sticks after I test them with 100A tester (so they will already be severely discharged I suppose)?

----------------------------------
I set a D>C cycle on T6200, but I guess there is a bug in software, so I couldn't see the discharge capacity, that's why it's missing. With all later sticks, I manually set the charger to discharge and then charge, so I could get all information properly.

Because I was only able to charge them for much less than 6000mAh. I was following ideas from this guy at that time (https://www.greenhybrid.com/forums/f...ry-pack-28610/) where he made decisions upon charge capacity.

You are right, I used aligator clips, will get ring terminals for the next "session" (or use the trick with bolting down aligator clips).. Again I followed ideas from the topic linked in the previous reply and that guy went as high as 9mV. So you suggest to always use 4mV cutoff?

Yes, I have a temperature probe connected to my charger and it never went higher than ~37°C (was charging with rate of 1C). I also always had a colling fan flowing air over the charging stick (and until it cooled down completely).

 

Thanks for the extensive reply. I will get down to business next week (need to gather needed tools and also I need a car for the next few days - not really comfortable driving around with 12V being charged only in limited range).

Now to the responses:
You are right, I'm from Europe. The voltage is 230VAC here (just tested at the outlet).

Just to make sure that I understand correctly, I make this discharge of sticks after I test them with 100A tester (so they will already be severely discharged I suppose)?

----------------------------------
I set a D>C cycle on T6200, but I guess there is a bug in software, so I couldn't see the discharge capacity, that's why it's missing. With all later sticks, I manually set the charger to discharge and then charge, so I could get all information properly.

Because I was only able to charge them for much less than 6000mAh. I was following ideas from this guy at that time (https://www.greenhybrid.com/forums/f...ry-pack-28610/) where he made decisions upon charge capacity.

You are right, I used aligator clips, will get ring terminals for the next "session" (or use the trick with bolting down aligator clips).. Again I followed ideas from the topic linked in the previous reply and that guy went as high as 9mV. So you suggest to always use 4mV cutoff?

Yes, I have a temperature probe connected to my charger and it never went higher than ~37°C (was charging with rate of 1C). I also always had a colling fan flowing air over the charging stick (and until they cooled down completely).