HCH1 IMA battery voltage reading & reconditioning
 

I'm trying to diagnose IMA issue(s) on my 2004 HCH. I've had the dreaded IMA light on for some time now along with codes 1600 and 1570. The problem is compounded by the fact that the car is overdue for emissions inspection which it won't pass with the check engine/IMA lights on. The Honda dealer wanted $4k to replace the pack and also told me that the 12v battery needed replaced.

So my first question is what voltage should I read from the orange lugged terminals coming off of the battery pack with the switch on?

After reconditioning the pack I'm only reading 76V using my digital multi-meter set on 200 DCV. It seems like that is about half of what I should be reading.

This battery pack is only 2 years old, it was replaced by the Honda dealer 2 years ago under warranty. I've read that what they give you is a reconditioned pack but I'm not sure that is actually true.

I cycled through all 20 sticks in the pack and the numbers looked pretty good. I used 3 SkyRC IMAX B6 chargers. All sticks in the pack were reading about 5300-5700 mAh discharge and about 7800-8100 mAh charge. Because of that I only did 1 discharge/charge cycle before topping off the charge of all sticks and reassembling the pack.

After re-installing the pack I cleared the codes using a scan tool and also tried battery disconnect, but immediately when starting the car the IMA battery comes on. And when driving there are no indicators for charging or assist. It is throwing codes 1600, 1445, and 1570. The red 12V battery light generally comes on below 1k RPM. I have charged the 12V battery also, but not sure if it is actually due to be replaced or is just being drawn down by the weak IMA pack (or both).

Re: HCH1 IMA battery voltage reading & reconditioning
 

I hooked up some alligator clips to the voltmeter and connected them again to the IMA battery terminals. I now see the voltage approximately as follows:

~ 85V @ idle
~ 90V cruising at 40mph @ ~ 2k RPM
~ 160V @ 2.5k RPM
~170V @ 3k RPM

Do those numbers seem normal?

Re: HCH1 IMA battery voltage reading & reconditioning
 

Please update your profile to indicate your location.

I regret to inform you that the SkyRC IMAX B6 you used tells you absolutely nothing about the suitability of the sticks. Yes, there are resources that document success with them, but the reality is that they can't apply a discharge load sufficient to truly test the sticks. Cycling sticks also give minimal improvement. You must deep discharge them (to near 0 volts) at low current to reclaim substantial lost capacity. Reversing these robust cells does not hurt them as so many references claim.

You need to buy the 500A carbon pile battery tester from harbor freight. You need to confirm that each stick can hold 5.4V under 90A load for 10 seconds.

Then you need to discharge at 10A and confirm that they have at least 5000mAh capacity at that discharge level.

Then you should recharge the sticks, wait a week and then discharge at 10A again to confirm that their self-discharge is not more than 1000mAh.

Note how none of those criteria say trickle discharge the stick at 700-900mA. A deteriorated stick can test great under those loads.

Assuming the pack was semi-functional before removal (would give limited assist and regenerative braking), concerning the voltage readings, did you turn the master switch back on? Did you reassemble and reconnect everything properly? What is the voltage at the pack with the car ignition off (not at the large terminals, those will be zero).

Re: HCH1 IMA battery voltage reading & reconditioning
 

Thanks Keith. Yes, I turned the master switch back on. Is there an ideal place to test the voltage on the pack without removing it?

Should I be concerned about the P1445 code (Bypass contactor) code?

Re: HCH1 IMA battery voltage reading & reconditioning
 

P1445:

http://www.insightcentral.net/forums...tml#post175048

battery:

http://hybridautomotive.com/insight/...allhch1/7a.jpg

The behavior you are describing suggests installation or assembly error.

Re: HCH1 IMA battery voltage reading & reconditioning
 

I will try to measure shortly from those points. What should I expect the voltage to be?

Re: HCH1 IMA battery voltage reading & reconditioning
 

This morning I replaced the 12V battery with a new one (it needed replaced anyhow).

I have removed the battery pack from the car again and carefully checked all connections and compared to original pics that I took and other pics such as the one on this thread. I've attached pics of the junction board side of the pack.

I did make one small but stupid mistake, which was to exclude the 4 8mm bolts that attach at the corners of the orange plate on the terminal side of the battery pack. It appears that those bolts do not provide an electrical connection and I am assuming that the exclusion of those bolts will not have any impact. I'd be happy if I were wrong about that. I have installed them now and will put the pack back together and back in the car for another test.

With the pack out of the car I measured 0V at the connections specified by the photo above with the master switch in either position. Is this the expected behavior with the pack disconnected? I will measure again with the pack connected in the car and the ignition off.

I measured 0 ohm across each of the 2 fuses and 12 ohm across the ceramic resistor.

With the junction board removed but the orange plates still connected, I measured the voltage across pairs of sticks and got almost exactly 16V for every pair.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Put everything back in the car, disconnected the battery for 10 min and then reconnected. I read about 48V at those terminals with the key off.

IMA light is still on, at idle (1k RPM) the red 12V battery dash light is on. Still reading codes P1600, P1445, and P1570.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Again, if you were getting limited assist/regen function prior to pack removal, you assembled it wrong or something was damaged in the process.

With master switch on, you should get ~160V (16V * 10) at the terminals you've marked +/-. The range could be as low as 120V if the pack is completely discharged and as high as ~177V if the pack/sticks were fresh off a charger.

See attached.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Thanks very much! That gives me something to go on. I will pull it apart again tomorrow and check what you've pointed out in the picture/diagram.

I was thinking that I was seeing 1/2 of the voltage that I should be seeing. But if I'm only seeing 48V it seems that I'm seeing about 1/3 of the voltage that I should be seeing.

Re: HCH1 IMA battery voltage reading & reconditioning
 

UPDATE - FOUND IT! I should have realized sooner that not having voltage across that last pair was an issue. When installing that first stick the first time I reassembled the pack, I over-torqued and twisted off the head of one of the bolts. (Those bolts are really soft! They can't take much torque at all). When I replaced it with a new bolt, it was a few mm too long and was making contact with the inner part of the battery. After substituting another bolt in that spot, I now see 16V across that last pair!

---

OK, so I went ahead and pulled the pack back out tonight rather than waiting until morning. I measured all of the points in your diagram (thanks again for that!).

I am seeing 64V between 1 of the pairs in your diagram and 0V between the other pair.

I removed both fuses and checked continuity on them and the both look read 0hm. Also removed the switch and check continuity and it is also functioning properly.

Diagram attached. Thanks again for your help!

Re: HCH1 IMA battery voltage reading & reconditioning
 

I believe you should be 96V across those two. I recommend you pull the board off and check voltages starting at one aluminum bushing and keep adding pairs. I can't imagine what the issue might be at this point. One or more sticks in backwards? I realize that would be hard given the shapes of the end plates, but there is enough clearance and flexibility to screw it up.

I know it's a hassle, but pulling the orange "cap" off and confirming orientation of the sticks is probably in order.

Re: HCH1 IMA battery voltage reading & reconditioning
 

I've pulled the board and orange plate off of that end of the pack. The orientation of the sticks and board are correct with alternating hex/square combinations which properly mate to the orange plate.

One puzzling aspect which I should have mentioned previously. Measuring voltages from the board side of the sticks and with the opposite orange plate installed, I see 16V across all pairs except for the top right pair (the one adjacent to the empty corner slot). I'm not sure if this is correct or not, but seems suspect. Diagram attached with red lines indicating the pairs where I see voltage.

Re: HCH1 IMA battery voltage reading & reconditioning
 

You have found your problem.

Confirm:

• Continuity between those terminals at the far board, i.e., confirm the board at the opposite end of the pack is connecting those ends of the sticks.
• Voltage of each of the two sticks.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Back in business! Steve - THANK YOU very much for helping me through this, I really appreciate your help.

Since I already had the pack apart and it has essentially been sitting for a week, I went ahead and topped off the charge on each of the sticks. Each stick took a charge in the range of 1350-1650.

I reassembled the pack and checked the voltages from the 2 pairs of points mentioned earlier in this thread. I'm now reading 98V and 66V at those 2 points (see attached photo). With the pack connected back in the car, the main switch on, and the 12V battery attached I'm now reading 164V at the 2 points illustrated earlier.

I started the car and no check engine or IMA light! Drove it a few miles around the neighborhood and everything worked great. Charge indicator went all the way up, charge indicator while braking, and assist and auto-stop were also working.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Why were you getting zero? Even completely depleted sticks measure > 6V unless they've been shorted.

If those two sticks were reading zero, something is very wrong.

Additionally, if they were last recharged a week, the charge numbers represent ~1000-1300mAh of self-discharge in a week. This is problematic. I suggest you investigate grid charging.

Re: HCH1 IMA battery voltage reading & reconditioning
 

NVM. I saw the update. Glad you got it sorted. I never tighten the bolts more than "wrist tight", and I usually just leave it with whatever I get via my 18V drill with the torque setting on 15 or so out of 25 and threaded in at full speed.

Re: HCH1 IMA battery voltage reading & reconditioning
 

I have a 2008 honda civic hybrid ,have had it out over 30 times going thru the battery and reinstall it. This time it has a p1570 code as usual,but the Car battery light stays on too and no bars are registering , even though i have 180 volts after charging with a grid charger. There is no assist and no brake charging either. And the battery charging is at 13.6 volts going down the road at 2000 rpms...but much lower 11.6 at idle. Good car battery btw....any clues why the car is not accessing the battery?
How do you test the dc to dc charger? tx

Re: HCH1 IMA battery voltage reading & reconditioning
 

Please post in the appropriate forum, and please don't double post.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Hi,
Great guidance and great work. I'm having some issues in my 2003 HCH1 with IMA Battery. I usually deep discharge the battery and works fine for a week or so but then becomes unbalanced. I checked the 20 individual packs and they take the load and have ~5.0Ah capacity. Main problem seems to be due to self discharging due to the age of the battery. Is there a way to check which packs are the worst, using OBD or while the battery is in the car? Also how to use a Grid Charger (I have developed a 300mA or 700mA one) to avoid self discharge?

Thanks and best regards,
Irfan.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Discharging without charging first is not a good idea. "take the load" and have "5.0Ah capacity" - what load? How was capacity tested?

No. Battery details can't be read from the car's OBD port - not even with Honda Diagnostic System (HDS). The information just isn't available.

Grid charging these batteries has been common practice for about 8 years. Most use various 350mAh LED power supplies. 2X APC-35-350 would work great.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Thanks for the reply. I started with 3 packs to get one good pack. Here's how I tested load and capacity.

6 cell stick, 0.9V/Cell, 50 Celcius, 5 min wait.
3 discharge > Charge cycles

100Ah 12V Deep Cycle Battery as Source.
Regenerative discharge 16A (300W max.)
sticks charged at 9A.

All good sticks between 5.0-5.3 Ah
Bad sticks, specially original pack ones, between 2.0-3.0Ah

I deep discharge the pack down to 20V using a 100W 220V tungsten filament bulb. After this the car runs fine (full assist for more than 10 secs) for about a week and then pack become unbalanced and IMA comes on.

For grid Charging I'm using Meanwell 3x RS-25-48 (48V 0.57A) and 1x LPC-20-350 (0-48V 0.35A) all in series. I made the Charger about 7-8 years ago, but I was not in my home country and the car was being used by my father.

Thanks and best regards,
Irfan.

Re: HCH1 IMA battery voltage reading & reconditioning
 

I'm guessing you copied the grid charger design from 99mpg.com

1) 16A discharge to 5.4V/stick is a good way to kill them. You likely did damage while cycling.
2) 9A is too high a charge rate. 1C is preferred.
3) if you ran sticks up to 50°C before the charge was terminated, you likely did more damage.
4) A 5 minute wait is too short. 20 minutes provides a more realistic capacity.

Your testing omitted what most people's testing omits - discharge over time. This requires > 1 week of resting. You need to start over. After you've determined capacity:

Charge sticks
Let sit for 7 days.
Measure and record ALL 6 CELL VOLTAGES PER STICK
Discharge to 6V and record capacity
Once you have all 20 sticks tested, the bad ones will be the outliers - the ones with highest CELL voltages variations within the same stick and the lowest capacity.

Also, grid charging without driving the cooling fan is a good way to kill the battery. The HCH1 uses a PWM controlled fan, so you will need to provide a means of control. Alternatively, you can ground the PWM line and drive it with a 100W+ 12V power supply.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Hi,
Grid Charger was from older 99mpg.com website, some other URL, but its a simple 350mA constant current supply which NiMH batteries require.

No sticks seemed damaged, that were good to begin with (tested at 6A charge/6A discharge).
No stick reached 50 Celsius cutoff, maybe due to high wind near seaside and pedestal fan near the setup. Wind did destroy/corrode the charger which was replaced under warranty.

I might not go to cell level testing, but we'll see.

For Now:
Out of 60 sticks that I tested for capacity and load, 20 out of my original pack and 5 more from other 2 packs were under 4.5Ah.
Since batteries are charged between 30 and 80 percent during use, I don't want to discard the sticks that can hold charge and provide 10C discharge current. I'm looking for a way to keep them balanced during night parking either by connecting a 5W or so load on the pack or permanently connecting the grid charger within the car (maybe with an inverter) and timer to top up every hour for 15 mins or so. Fan should not be required but supplying PWM to it won't be a problem.

Thanks and best regards,
Irfan

Re: HCH1 IMA battery voltage reading & reconditioning
 

Your pursuit is folly.

Capacity is the least important characteristic. Do the testing as I prescribed, or you're just going to go in circles never finding a solution.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Then how about replacing (or adding) a lithium polymer set. 40S should be the same nominal voltage with LiHV taking a maximum of 174V. I know that LiHV require CC-CV for charging but if I can determine that the maximum charging voltage is under 174V, it can work.

Re: HCH1 IMA battery voltage reading & reconditioning
 

It will work perfectly until the car rams 50A into it at 211.2V. The IPU might even contain the fireball long enough for you to escape.

Re: HCH1 IMA battery voltage reading & reconditioning
 

211.2 would be for 132 cells on HCH2. For 120 cells shouldn't it be lower?
Also if used in parallel with NiMH, most of 50A would go to NiMH. Otherwise Lithium Polymer BMS could be used.

Re: HCH1 IMA battery voltage reading & reconditioning
 

The fire would occur at 192V instead.

Re: HCH1 IMA battery voltage reading & reconditioning
 

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.

Re: HCH1 IMA battery voltage reading & reconditioning
 

Hi guys could you please help me as I'm confused now
I have Honda civic 2007 and trying to recycle cells which are in my opinion in not as bad state
each double pack (12cells) holds between 14.8-15.8v (middle ones the least)

Now I can't take them apart to split doubles as I don't have a way to solder them back so have to charge each double pack
I've set initial numbers to
charge @5A
discharge @ 1A
cut off V @ ?
timer to 148min
cut off peak @ 5mV
capacity @ 11000mah

Could you please confirm those values and tell me what should be cut off V as I'm not sure, I believe 1Vxeach cell so 12V would be too low ?
should I then set it to 14,5V ?
Should I adjust any other values ?
Also should I just connect them to ends on plus and minus or any other way ? (I'm using imax b6)

Re: HCH1 IMA battery voltage reading & reconditioning
 

You can continue to cross post. I'm not going to hand you the hammer with which you'll bash your brains out for the next month. You're using a toy.