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ok, i am getting very frustrated. my IMA is doing the up/down, charge/regen/uncharge BS again.

i was talking with wayne last night, and he mentioned the best way to work the thing is to stay off the IMA, and use as little assist as possible, which is what i try to do. BUT....this thing gives me an assist for the smallest possible pressure i put on the pedal, in first gear just starting out, accelerating on the highway, up hills it almost pegs out sometimes.......other times it just gets low while i am driving, with no reason i can see. today on the road it was doing a forced regen with a little below half charge on the gauge. other times i will try to use assist and it will stick at 4 bars and i can't get it to add any more.

something is just not right. sean drove it a week ago, and maybe he can explain it better than i have. it did it over the weekend, and on my way home tonight.

i have an appointment with honda next week for an engine block heater, and i would like to go in there with enough information about how this thing is supposed to work that i can clearly tell them that's it's not right. if anyone has any ideas or input, i would sure appreciate it. or any websites that describe in detail how it's supposed to work, so i can tell the tech that no, its NOT supposed to discharge to half every time you use it.........

thanks. whine done. for a while.

...if anyone has any ideas or input, i would sure appreciate it. or any websites that describe in detail how it's supposed to work, so i can tell the tech that no, its NOT supposed to discharge to half every time you use it.........


Depending on your level of confidence on your dealership's technical abilities I would shamelessly dramatize the circumstances and I would "steer them towards" any of the following:

A - A "full cycle" battery test where they test the effective battery capacity.
B - A BCM software update (assuming you haven't had one in a long while).
C - A BCM module replacement (assuming that it does not diagnose properly or it is too outdated).
D - And finally, a battery pack replacement accompanied by either B or C depending on the circumstances. The normal procedure in my "neck of the woods" is to ultimately have C & D done.

Lastly, there are many folks who just have no luck with their local dealership. Quite often the trick is to try your luck at an alternate location and even engaging Corporate or Regional Honda. Battery replacements on Gen 1 HCH's with manual transmissions are quite common... and as of my last check, Honda had performed quite a few in Canada alone.
Given the precedents, I know for sure that if you push them a little you'll have no big trouble getting C & D performed.


Cheers;


MSantos

Hi Laurie:

___Do not worry about a little assist on any launch as Honda set up IMA hybrids up for this and the HCH-I’s and II’s are just as bad as the Insight. If you are really careful, you can launch with minimum bars for only a few seconds but it takes a light foot.

___As for the SoC dropping out, can you let Sean drive your HCH-I down to the Milwaukee Hybrid Group meet this coming weekend? I would like to pull the battery terminals to force a recal event upon reconnect. I am interested in how your HCH-I’s SoC runs back up with maybe 3 or 4 miles of easy highway driving. It should run up to 1 bar from full and then hang there with no assist events.

___Maybe you can setup a small Hypermiling group meet up in MN. for Sean, Rick and yourself? Let us say two weekends from now and I can drive, take an Amtrak or Greyhound up that way and we can do a few hour clinic?

___Good Luck

___Wayne

Laurie et al, I just spent about 50 min scouring the web for behavior characteristics of the 5spd Civic IMA system. I wasn't able to find any specific specs (such as, assist begins at X engine load), but everything I found indicated that cruising should not draw down the battery. Neither should gentle acceleration if the SOC is over 1/2. This isn't consistent with what I saw when I drove the car.

I've been doing accelerations so slow I call them "drifting up to speed" for years. No so much recently because P&G is so much more efficient, but I'll still do it under certain circumstances. I'm talking 5mph gain over the course of 1min or so. I tried this with Laurie's car and it assisted. On a flat. I tried maintaining speed. It assisted. From 2/3rds full down to about 3/8ths, then the forced charging started (at 1 bar under 1/2), and continued as the charge dropped down to about 1/4th. It didn't recover for the entire drive of what, 20mi or so?

I expected assist from a start, but given the acceleration rates I was using it should have dropped out as I hit 10-15mph or so. No dice. In combination with the fact that the car does not always act this way, I'd say there is something seriously wrong with the system on at least an intermittent basis.

I did see some stuff about BCM updates/replacements online but I don't know enough about what those do to judge if that might work for this behavior.

Wayne, I'd be up for a clinic meet. :) Selfishly, I'm in the middle of the three of us... ;) You'd be welcome at my house if you need to split the trip up and get some sleep -- I've got a guest bedroom all set up. Of course, I'm assuming you meant the weekend of the 3rd/4th? If it is the weekend after I've got my sister up to visit and I don't think I could get away.

Laurie, if you want to have me drive your car down to Milwaukee I can leave you mine -- but I'd have to swap Friday afternoon. Any chance you'd be down in St. Cloud? I would have to return it Sunday afternoon as I've got to get to Church in the morning.

If you're doing FE clinics on the weekend of the 3/4th, I'd probably be able to make the drive over from La Crosse, just across the border. That would be nice especially if I can't make the MiHG meet this weekend.

Laurie,

Sorry to hear you are having problems. From what I am reading, your 05 does not act like ours at all. Have you had the computer reprogrammed for the recall that was out awhile back? As for a group meet, I believe I could round up some folks that would benefit from that from around here. From what I have heard, the hybrid knowledge base varies considerably from dealer to dealer. If you are not satisfied with your dealer maybe you should consider the dealer in La Crosse. I believe the knowledge there to be top notch. Hope you get something worked out.

Laurie,

http://www.99mpg.com/data/mima/install/rearoverview.jpg

While it's a picture of an Insight's batteries and supporting network of computers directing the charge/recharging, it should be basically the same on your Civic.

The BCM is the little computer sitting on top of the battery pack, networked to the batteries and other units. It's duty is to determine the State of Charge.

Early Hondas had BCMs that let the SoC go down to 15% - it's been changed since the recall to 40%. Make sure they upgraded it.

Depending on your level of confidence on your dealership's technical abilities I would shamelessly dramatize the circumstances and I would "steer them towards" any of the following:

A - A "full cycle" battery test where they test the effective battery capacity.
B - A BCM software update (assuming you haven't had one in a long while).
C - A BCM module replacement (assuming that it does not diagnose properly or it is too outdated).
D - And finally, a battery pack replacement accompanied by either B or C depending on the circumstances. The normal procedure in my "neck of the woods" is to ultimately have C & D done.

Lastly, there are many folks who just have no luck with their local dealership. Quite often the trick is to try your luck at an alternate location and even engaging Corporate or Regional Honda. Battery replacements on Gen 1 HCH's with manual transmissions are quite common... and as of my last check, Honda had performed quite a few in Canada alone.
Given the precedents, I know for sure that if you push them a little you'll have no big trouble getting C & D performed.


Cheers;


MSantos
thanks! this is most helpful. i have been in several times with similar complaints, and i think they have done 2 software updates, with not much change in performance. i am going to start my request today, and call them asking them to work on this while the heater is going on. perhaps if they have over a week to think about it, their tech will come up with something. generally, i have felt OK with their service, much better than the one that's 3 miles from where i work.

Wayne, I'd be up for a clinic meet. :) Selfishly, I'm in the middle of the three of us... ;) You'd be welcome at my house if you need to split the trip up and get some sleep -- I've got a guest bedroom all set up. Of course, I'm assuming you meant the weekend of the 3rd/4th? If it is the weekend after I've got my sister up to visit and I don't think I could get away.

Laurie, if you want to have me drive your car down to Milwaukee I can leave you mine -- but I'd have to swap Friday afternoon. Any chance you'd be down in St. Cloud? I would have to return it Sunday afternoon as I've got to get to Church in the morning.

sean, thanks for the good description. i am going to print that out and take it with me when i go to the dealer.

as for taking the car, i will be in st. cloud at work friday afternoon, if that's not too much driving for you. and sunday afternoon, i will be at the barn....as usual :)

wayne, is the weekend you are talking about november 3-4? that's the saturday i am having the heater installed, so i am going to be up there for most of the morning, i suspect.....so i am not sure what that would do to your schedule. it would then take me at least 2 hours to get to sean's. or there is sunday.....i appreciate your offering to do us a clinic up here. wow, that's way above and beyond.

Laurie, I'll plan to drive your car then.

That weekend of the 3rd has a couple of things going on in it but I'll hold my peace until we have more input. :)

have i mentioned that everyone on this forum is SUPER???!!!!

i called honda service and told them i wanted them to add time to my visit in order to do some diagnostics on the IMA. i told him approximately what's been done as far as upgrades, and how it's been acting. i also told him i will have a written description, based on sean's experience last week, and anything that might act up when he takes the car to milwaukee this weekend. the service guy seemed open to that, so we shall see what happens. i am, however, going to insist that it is not acting as it should.

thanks for all the input, and for sean and wayne for going the extra mile.

Laurie, I'll plan to drive your car then.

That weekend of the 3rd has a couple of things going on in it but I'll hold my peace until we have more input. :)


barring bitter cold ,snow, sleet or inadvertant dismemberment ...I think I'm free. "Say when" I'll see what I can do.

Dismemberment?? :eek:

Laurie, I hope the documentation of behavior helps! I'll keep an eye on it and I'm sure Wayne will have plenty of input once he has a drive in it (provided it acts up at that point, of course).

Hahaha um yeah , I work in a glass plant - it's considered a "non handbook fringe benefit."

Hahaha um yeah , I work in a glass plant - it's considered a "non handbook fringe benefit."


Off topic:

But I worked in a glass plant once. Maint. Sparky. Walked into the hot end. Thought to myself. " OOOO God did I mess up " A new mistake in the top ten of my life. Thank god I only spent 6 months in that culet making nightmare.

The MT Insight batteries can exhibit the same type of battery behavior as your MT Civic, since they are virtually the same battery pack and configuration.

NIMH batteries like NICD batteries will develop a memory if not cycled through the full operational range occasionally.
While Waynes MPG advice of not tapping into the assist with FAS and P&G can yield some nice numbers, the jury is still out as to what that type of battery use will do to the life of the battery.
The Prius does a reconditioning full cycle every few months.

A recent piece of feedback from a EE in Austrilia that just put in MIMA:

"Just seen your battery reconditioning activity on your web site.
What I my not have mentioned is that I have extensive professional experience with battery powered, actually battery backup power of commercial Broadcast radio stations, These are big and the best are liquid NiCad batteries.
I have done extensive experiments to get the best life out of the batteries and here are some of my findings.

A good quality set of NiCad batteries, both liquid and gel should last about 10 to 25 years, I currently use some that are over 15 years old and they provide a full charge like new ones, although total power stored is down 15 to 20%
NiCad and NiMH both like to be used and used hard, but must be given a rest so they are allowed to return to about 25 degree centigrade for 2 hours.
Although the manufactures state differently, we found that the batteries recovered better when they are completely flattened, 0 volts output. then charged at 10 to 20% of charge capacity for 12 to 6 hours. We experienced no shortening of operating life by this deep cycling.
Our battery backup system got used each night so the batteries would be exercised and that way we also knew if a the system had any problems, before they actually needed it.

As a side note, the building that housed the batteries was destroyed by a hydrogen explosion which came from the batteries boiling when a normal metal spanner was brought into the battery room and was accidentally dropped across a buss, the spanner welded its self, then all hell broke loose.

It is good to see some one doing a cell recovery. I will be doing mine when the recals start."

As a point of reference, my Insight pack with 122K on it has never had a recal, and I use it hard.
;)

The MT Insight batteries can exhibit the same type of battery behavior as your MT Civic, since they are virtually the same battery pack and configuration.

NIMH batteries like NICD batteries will develop a memory if not cycled through the full operational range occasionally.
While Waynes MPG advice of not tapping into the assist with FAS and P&G can yield some nice numbers, the jury is still out as to what that type of battery use will do to the life of the battery.
The Prius does a reconditioning full cycle every few months.


As a point of reference, my Insight pack with 122K on it has never had a recal, and I use it hard.
;)

thanks. i totally understand what wayne means about staying off the battery. the problem i am having is that it won't let me. as sean noticed, just starting up at a low crawl turns on the assist. most acceleration also causes assist, when it's in one of those discharge moods. i can't help it. and it's not acting like it did when i first got the car, that's the part that makes me suspect. perhaps wayne will find out something this weekend when he tests it..........:)

I think you missed my point.:(
A lot of battery pack issues with the Insight and early civics, has surely turned Honda engineers onto the need for pack cycling as part of normal care and feeding.

The Civic IMA may have a battery maintenance procedure like the Prius where it occasionally trys to exercise the pack.

If the aggressive assist behavior you are experiencing is in fact the car trying to cycle the pack a bit, and you are not allowing it to do it, you may be stuck mid procedure.

As painful as it may be, the car may just need to be driven hard once and a while to reduce the chances of the battery memory effect developing.

Only my opinion, but the evidence I am seeing is starting to point in this direction.
Good Luck
;)

Hi Mike:

___The real world evidence is in with 100’s of Insight packs being replaced that were cycled from one end to the other. This has lead to shorter life spans as has been seen in just every battery study ever written. This is not a memory issue but a chemistry one. As for your own pack never being recal’ed, every time you have disconnected the 12V you have forced a recal and I know you have disconnected the 12V more then a few times without a small supply to keep the BCM live, correct?

___Prius packs not only have an online recal event that is all but seamless to the end user and over a much smaller range than what the Honda allows, it was designed for upwards of 300,000 mini charge/discharge events (not full cycles) and thus its superior longevity. Allowing a full charge/discharge cycle limits a NiMH batteries lifetime severely and should never be considered as your pack whack procedure describes. Once every 6 months, sure. Weekly or monthly besides all the cycling MIMA inputs? That is some awfully expensive advice. NiMH’s have a limited lifespan due to charge/discharge events and allowing only minor hits allows superior longevity without question.

___Good Luck

___Wayne

For what it is worth, my understanding tallies with Wayne's description. Essentially, deep discharge cycles tend to create compounds which do not break apart and add internal resistance to the battery. This is what lowers energy density. Keeping the ions separated as much as possible (battery fully charged) slows the process enormously -- though age will still cause a slow accumulation of such compounds.

Once those are at a sufficient level, regardless of memory effect, your battery becomes effectively useless because its internal chemistry is "clogged."

If the BCM is out of whack and not correctly determining how much charge is remaining, or how to effectively condition the battery, this might explain the "runaway" behavior we are seeing?

With several hours of travel time on the highway coming up, if I see such an event I'll have the time to see if it will eventually recover, then act normally. The inconsistency is what makes me suspect the electronic components -- though battery aging could easily be a factor.

gentlemen, you have gone way past my knowledge base. my eyes are glazing over as i read this, but i know that between you all, you can help figure out what's going on. i can be very mechanically proficient in some areas, but not this. the left brain kicks in and i get lost......

thanks for all the input :)

Wayne,

How far down would you consider safe on the Insight battery pack? My guess would be the safe SoC would be 20-15 bars.

I'm glad the temperatures have cooled - no longer have to worry about my battery pack cooking in the parking lot. :)

Hi Chuck:

___On your Insight, minimizing pack use (assist or regen) throughout your normal drive while leaving the SoC high other then the few times a year you may be climbing mountains would be best. I think you already know the best way to climb a mountain with a 5-speed Insight but that is for another thread.

___For Laurie, I just want to see your HCH-I’s recovery after a Forced recal and how she acts afterwards is all.

___Good Luck

___Wayne

"___The real world evidence is in with 100’s of Insight packs being replaced that were cycled from one end to the other. This has lead to shorter life spans as has been seen in just every battery study ever written."

I would really like to know where you got that information.

Ask any EV guy about battery cycling and pack balancing, I am not making this up.

For one thing the packs are not cycled from end to end, the BCM does its best to keep the SOC between 20% and 80%. good for 100K cycles
When you don't use the pack, it develops a memory just like a power drill battery that has been used sparingly, the 6.5AH can become 1 AH. Cycle them a bit, and they will come right back.

Recals are when the SOC estimate gets skewed, and it keeps hitting a lower voltage limit prematurely since it never gets properly charged.

I realize how hard it is for some hypermilers to exercise their motors and electronics.

It could ruin their MPG. I am only offering my opinion for what it is worth.
Send me those links.

"___The real world evidence is in with 100’s of Insight packs being replaced that were cycled from one end to the other. This has lead to shorter life spans as has been seen in just every battery study ever written."

I would really like to know where you got that information.

Ask any EV guy about battery cycling and pack balancing, I am not making this up.

For one thing the packs are not cycled from end to end, the BCM does its best to keep the SOC between 20% and 80%. good for 100K cycles
When you don't use the pack, it develops a memory just like a power drill battery that has been used sparingly, the 6.5AH can become 1 AH. Cycle them a bit, and they will come right back.

Recals are when the SOC estimate gets skewed, and it keeps hitting a lower voltage limit prematurely since it never gets properly charged.

I realize how hard it is for some hypermilers to exercise their motors and electronics.

It could ruin their MPG. I am only offering my opinion for what it is worth.
Send me those links.

am in correct in interpreting this as it needs to be pushed to the limit at times? i am not asking this in a sarcastic manner (see my last post) but asking if this is what you are saying?

Hi Mike:

___You know where all the packs are failing unless you have not been reading the boards the past few years? Feel free to look them up for yourself whenever you find the time. Feel free to let us all know after you stopped counting at 100.

___Cel balancing is a good thing and why the cel’s in an Insight pack were cap matched to begin with which helps improve longevity and reliability of the entire pack. Any time a cel or pack gets “whacked”, a bit of its life disappears “forever”. The deeper the cycle or higher the C-Rate, the worse the damage.

___As for memory, Ni-MH’s have far less memory then a Ni-CAD IIRC and a Prius is proof in practice. Honda opened up the throttles on the DoD and C-Rates and Insight owners have been paying the price for years. An Insight has the most delicate pack of all the hybrids sold in the US given the accounts of replacement packs. Hammering away at them only reduces their cap and their life all that much sooner.

___Every touch of the pack takes life out of it. Every hard hit of one takes a lot more life out of it. Thus the reason to be careful on any accel to minimize assist and the long term damage caused by continuously going to the well. We all know the beast way to drive a hybrid for FE and most reading this now know the best way to destroy one. You know which hypermilers to contact wrt recals that finally brought in the IMA code of death. In fact, many actually hope for it so as to get the new pack.

___In Laurie’s HCH-I case, it sounds like the BCM is FUBAR and with that, the pack is probably beat up somewhat. We can only hope to nurse it back to health w/ a forced recal and pray it does not happen again?

___Laurie, a battery does not need to be pushed to its limits with a SoC draw down test for overall cel longevity. It is a bad thing to be playing that game given deep discharges are killers.

___Good Luck

___Wayne

If I can summarize:


Mike says drain the battery pack every several months
Wayne says never drain the battery pack - keep the SoC near the max at all times.Hopefully that accurately states the two positions.

Hi Chuck:

___I am saying never, just when the opportunity forces it. If never, good but if you travel in heavy traffic and are not really careful or any hilly area, it is going to happen.

___Mike loves running high C-Rates including deep DoD’s at any time and we all know what that does to a cel’s chemistry let alone a pack. Minimize the hit and the longer the life.

___Good Luck

___Wayne

I was trying to get some clarification.

The last few weeks, I've gotten down to the last 1/3 SoC more than Mike would probably care for...

Hi Chuck:

___As we have talked previously, if it were my Insight, I would want the pack to last the life of the vehicle and the one way I know how to make that happen is by minimizing both assist and regen events and cracking the windows in any type of open exposure sunlight so as to keep the cabin temp too not much more then a few degrees above ambient. If you were to drive down SoC for P&G, get it down there and leave it down there for the entire period you would be playing in that realm just as we did at the Insight Marathon Attempt. For a Tour De Sol type rally, you may burn 10 bars over 5 – 7 miles of a mountain climb but that happens once and she will come back and hold at 19 of 20 for all the easy driving highway and descent stuff afterwards. Every day driving, stay out of it and leave it high. You have already lost one pack and let’s try and keep it to one because I doubt the next one will be free.

___Laurie, sorry this thread is not going in the direction you originally intended :(

___Good Luck

___Wayne

Off topic:

But I worked in a glass plant once. Maint. Sparky. Walked into the hot end. Thought to myself. " OOOO God did I mess up " A new mistake in the top ten of my life. Thank god I only spent 6 months in that culet making nightmare.

Missed this post Jeff . Fortunately I do not work in a 'float' plant ( Hades is cool comparatively). We did have a tempering oven as well as a chem temp tank- super heated sodium chloride til it turned liquid- at one time though . Plenty warm .I've worked in this automotive replacement glass manufacturing facility since 1986. That will be changing in the next week or so . Cullet ...millions of tons of it .Yup indeed. Kind of hard to dismiss 20+ years as a 'mistake' - but it was. ;)

Sorry to hijack laurie :o back to your regularly scheduled IMA infomercial (I'm learning ! :flag: )

laurieaw,
Yes I am suggesting that giving the pack a good exercise by driving it hard may improve things. Drain it by heavy assist till it limits at the bottom, and let it regen to its hearts content to refill the pack. You cannot push it beyond the built in safe limits.

If hitting the pack hard has not caused my pack to misbehave after at least 45K of MIMA, and a total of 122K, and many other people using their pack lightly, are having problems much sooner than that, would at least be one case where Waynes assumptions about battery use have proven incorrect.

Remember the design of the Insight and Civic included the IMA, and the design of the IMA assumed that people would use it. When you do not use it, your behavior brings you outside of the design envelope. We can only make assumptions about how the car dealwith that.
M Santos confirmed in another thread that the Civic will dump charge and boost assist when the pack is too full, just like the Prius, and unlike the Insight. It would seem logical that they would also have worked in an occasional battery extended cycle like the Prius to erase any developing memory effect, which while being less than NICAD's is still a problem.
I don't want to get in an opinion contest with Wayne over this, we have disagreed on this since before MIMA, and are unlikely to agree now.

Yes many Insight packs are being replaced, but what is really wrong with them?
Did the way they were used have any effect on their premature failure?
Can a simple conditioning cycle or two make the pack behave better?
How long will the re balancing correct a flaky pack?
Not enough information for a definitive answer in my book.

That is what I want to finally determine, rather than make assumptions.

Again good luck with your visit to the service department, and I would not suggest that you try the hard driving until you see if they can find anything.

Hi Mike:

___I am glad you directed your response towards Laurie and no, beating the hell out of the pack is the wrong thing to do. Force a recal via the 12V and watch the results closely should help or at least temporarily fix this problem.

Yes many Insight packs are being replaced, but what is really wrong with them?

Ask Honda, given they are replacing them to the tune of $1,500 - $2,000 OEM with the Inverter, BCM and pack.

Did the way they were used have any effect on their premature failure?

It was either heat or use. Driving Bradlee’s Insight across the country and back while managing the pack properly (minimal to no assist and regen’s accel’s/decel’s) saw no recals over 2,500 miles including climbing the mountains of New York in the Tour De Sol even though his Insight was prone to Recal’s.

Can a simple conditioning cycle or two make the pack behave better?

No. Do you think Honda would not try and limit the $’s and reputation fall out with a procedure so simple. New pack rebuilds with some new cap matched cel’s (Honda’s method) don’t recal right off the lot that I have read until they are beat up a little again.

How long will the re balancing correct a flaky pack?

Not long if at all. “There was a member using your whack pack procedure who said he has “fewer” recals.”

Not enough information for a definitive answer in my book.

Honda Extends Battery Warranty to 150K Miles

VEHICLES AFFECTED

This warranty extension affects all 2000 - 04 Insights (Source: Honda Service Bulletin 06-027, May 27, 2006)

BACKGROUND

To ensure continued reliability with the IMA system, American Honda is announcing an IMA battery warranty extension for certain 2000 - 04 Insights. The IMA battery is now covered for 10 years or 150,000 miles, whichever occurs first. This warranty extension applies only in states where there is an abnormally high replacement rate for IMA batteries. (Expanded to cover all states IIRC.)

CORRECTIVE ACTION

Replace the IMA battery if it has failed.
___Fortunately, Laurie owns an HCH-I and they have had far few instances of this problem then the Insight’s. I doubt her HCH-I needs a pack due to damage given the Make and model hybrid, year, low miles and she hasn’t been racing it other then snow tires and a few miles of gravel road travel but hopefully we can help find out what the story is this coming week.

___Good Luck

___Wayne

I have been cracking the windows while in the parking lot in hot weather.

Again, I think both Wayne and Mike would agree in the last month I have visited the last 1/3 of my SoC too often - I'm getting better at keeping the decent to about 1/2 of SoC.

Funny aside - I'll be hypermiling in the 45-55mph range in the rightmost freeway lane and lately, I've enountered more drivers on the entrance ramps trying to use the shoulder while doing 60-70mph. {sigh} Tonight I managed to thwart such a driver and the SoC only went down from 20 to 18. :D

One thing I've noted is charging/discharging tends to heat up the battery pack...therefore I have used light Assist, although I will be heavy on the Charge.

Honda does not allow dealer techs to touch the pack innards, so replacement is their only option.
The subpack by subpack re balancing is not easy, the pack must be pulled, and disassembled, and the cycling takes several hours per subpack, or more than 50 hours total. Replacement by the dealers is their only option, given the price of labor. The modules are changed to get new MCM and BCM firmware which many have indicated is much different in IMA usage.
When Honda takes the old pack back and rebuilds it, we really do not know what they do with them do we?

A Pack whack test while being the first procedure in the history of the honda Hybrids that did essentially erase a repeating recal condition, did not fully charge any lower capacity subpacks since they were in series.
We need more people to try rebalancing to get more experience.

The individual subpack conditioning is the next best thing to rebalancing each cell with a fixture (we could do that as well).
You are making sweeping assumptions and stating them like they are facts.

Always better to look at this type of problem with an open mind, and do the necessary test and analysis to make a definitive diagnoses.

The results of our testing will be made available to all.

I am finished on this subject, and again hope that laurieaw has good results at the dealer.

CU;)

Wow, nice discussion.

I can see some opportunities for confusion particularly regarding what is best for our NiMH packs. As I read through the posts I do see some pretty good info that is pretty valid and maybe we can put it all together in a way that is neither complex nor does it trivialize what is going on in terms of battery management patterns.

Based on some of the info I have access to, I then will make a few cold statements first:
- To ensure long life, A battery pack must not be subjected to frequent large oscillations in its charge/discharge curves.
- A consistently topped off battery is just as undesirable as a consistently depleted battery.
- The ideal voltage for a typical cell is usually determined by the combination of the nominal charge and discharge curves. So in a series arrangement like our battery packs are, this maps into a now typical SoC range of 60% to 80%.
- Contrary to popular perception NiMH chemistries have been found to still suffer from some memory effect. Although not as severe as that of other/older chemistries (NiCad) these are still observable especially when the deltas in charge/discharge rates are small and persistent.
- Battery management routines and patterns are nothing to sneeze at. They can be very complex and depending on how well a manufacturer/designer understands the profiled field/test data these can take far more parameters into account than what is commonly considered. As we know, temperature, SoC, Charge and Discharge rates are both inputs as well as conditioned outputs. (I believe Toyota has understood and mastered these ealier than Honda).

Now, if I understand Mike correctly, what he's saying is that incurring "strategic" deep discharges may have a quantifiable benefit. Am I right Mike?
Well, based on what I see as part of the current pack management routines & patterns in addition to the many profiling results released by the industry, I believe there's a great deal of merit to this.
I would say that the key to this function lies in the "strategic" nature of process. It cannot occur often at all and is must be evoked strictly to contain the cell's afinity to slowly and viciously degenerate to a level below its original nominal capacity. Although I have yet to see such a deep cycle discharge occurrence in either of my two HCH-II's or in the 3 Prius-II's I bought for my company, I believe this process is now a critical part of the battery management/conditioning routines.

It is conceivable that the HCH-1 and Insight may implement a far less aggressive set of management/conditioning routines simply because Honda had yet to learn from the data it is now still collecting. Things get even worse for models equipped with Manual Transmissions as the computerized management control is subject to the input provided by the driver as well as the driving conditions, thus denying the possibility of a more controllable battery conditioning strategy. So maybe carrying out Mike's suggestion on these models may be a key? Sadly, I cannot find any info regarding this issue for older hybrid models. I'll keep looking. Until then experimentation may hold the answer for folks like Laurie.

More on Manual Transmissions:
It is on this basis that I agree, that equipping a hybrid with a manual transmission is a bad design choice and I am happy Honda will make MT equipped hybrids a thing of the past (sorry I do not mean to offend anyone here as the MT models have been the FE champions).
Honda now knows and admits that it was a "mistake" of their part and that is why they will usually offer little resistance to a pack+ BCM replacement for MT models. If I were to own such a model I would certainly exercise that option ASAP as soon as I notice behaviors similar to what Laurie reported. After the replacement though, I would baby that pack as if it was gold. ;)

I should also add, that even the CVT equipped models are not totally free of ealier battery failures especially if they are driven in harsher topographies. Honda has acknowledged this too and has stepped to the plate on this as well by offering pack replacements for these owners too. Although the HCH-II's pack is managed far more agressively than the prior (IMA1, IMA2 and IMA3) platforms, Honda knows that some people living in tougher topographies may be the ones checking in first with battery failures for these models too. The question now seems to be how quiclky that will happen. It remains to be seen if the current management/conditioning formula will accommodate the std warranty period or not.
Even for CVT models, the problem when operating in these topographies seems to be the frequent Top offs (descents) and Discharges (climbs) that mountaineous drivers seem to experience on a regular basis, again violating one of the rules listed above.

Now, I also see a great deal of merit in Wayne's assertions. Honda has a knack for implementing and deploying these assist routines that appear poorly balanced with the regen patterns.
In other words, we have the high afinity assist kicking in for even the slightest gas pedal input. In a regular driving session this creates a barrage of micro hits on the battery pack (which although not harmful by themselves since they are of low amplitude) happen to not be balanced by a reciprocal and more frequent regen pattern. And when a managed regen does occur (inevitably), it occurs a little too late IMO which causes a greater deflection in the state of charge. Maybe I am missing something here, but most techs I talk to seem to think this is still an area for improvement as well. It remains to be seem what additional future tweaks Honda still has in store for us HCH-II owners.

So I agree with Wayne that minimizing the frequency of the hits on the pack has much merit and if the assist patterns are too agressive then perhaps the owner should take control or balance the process through whatever means possible.
For instance, on my wife's car I often try to place the car into hidden regen as a means of minimizing the amplitude of the swings in SoC. I have almost given up controlling the assist part since Honda's latest software updates seem to have more control over the system than what I assumed originally.

Anyway, I hope I have not fumbled things even more. But if I did please point it out and I'll do my best to explain.

Cheers;


MSantos

Nice overview.
Only a couple of points.
The information I have seen on SOC range for the Honda Insight was 20% to 80%.
Is the civic range different?

Since hitting the pack cannot go beyond those limits, and the limits have been determined to give the best compromise of available capacity and long life. It is not really a hit at all, rather it is a normal short cycle.

Looks like a good data acquisition system to log battery cycle depth and frequency would shed more light on the normal behavior than any of our speculations and assumptions will.

We should have more real world feedback on the effect of pack rebalancing and the effect on recals over the next month or so.
I will wait to make my final determination until after we get the results.

Nice overview.
Only a couple of points.
The information I have seen on SOC range for the Honda Insight was 20% to 80%.
Is the civic range different?



Indeed it is. Occasionally, the system will let the charge go down to 2 out of 8 bars but those incursions occur rarely and at rather strategic times (for instance, when it is too hot) - it almost amounts to hitting two birds with one shot (apologies to bird lovers go here).
While the typical owner will freak out and wonder what's wrong, the event is definitely managed and should be regarded as part of the normal pack maintenance routine.

However, the "normal" operating charge range is 60% to 80% for the newer IMA platforms. I believe IMA3 is also a little more stringent in complying to these thresholds as well.

I suspect the 20% to 80% range for the Insight was derived from an early and rather academic interpretation of the charge/discharge curves for the NiMH chemistry. It is my belief that those specifications were precocious and did not (and could not) benefit from the experience that Honda would eventually acquire.
Again from an academic view, the 20% to 80% basically clips off the "danger zone" ranges of the curve (at the top and bottom) but leaves very little head-room for deviations and other high tolerance scenarios.
Since heat is still a monumental problem, "particularly" during the charge process and high discharge rate scenarios it makes sense to shrink and slide the operational window further up the curve, just for the sake of ensuring a longer life.

The info I got concerning the battery recycling program is that used "battery samples" are forwarded both to the client (Honda & Toyota) and to its manufacturer (Panasonic & Sanyo) for subsequent analysis. I do not know what the statistical facts are in regards to the sample sizes and eventual fate but I have been assured that they offer much value to the client as they do to the manufacturer. I do not know if after the pack and module disassembly the complying cells are fed back into the system as part of replacement packs or simply recycled.
As engineers we often frown upon re-feeds, but I guess we'll never know what additional data they have and what kind of financial pressures exist that will make that acceptable. ;)


Cheers;

MSantos

I am curious as to where you got the 80%-60% SOC information for the newer IMA systems.
Thats only 1.3AH, compared to the 3.9AH that the Insight may use from the same batteries.
Boy have we deviated from the original thread subject, sorry to have shifted the focus.

I think you guys may be talking about two different things. I have regarded (and I think Mike is talking about) the 20-80% DoD as the absolute limits of the pack per the BCM. (On a Prius it's 40-80% IIRC). So when the gauge reads dead zero you're at 20%, full means 80%. MSantos, it sounds like you're talking about percent of usable range rather than percent DoD. Maybe?

I like the idea of rigging a data acquisition system to record DoD, charge and discharge rates over time. It would be interesting to compare the varios Honda control schemes with what Toyota does. A Prius will keep the battery at one level all the time but there's always some activity registering on the MFD into or out of the battery even at a flat cruise.

Something else I've heard: it has been suggested that batteries have a "break in" period of their own where efficiency increases somewhat during the first part of their life. Any truth to that?

Anecdote:

I have a battery charger for AAA and AA NiMH and NiCd cells. It has a "refresh" function, which performs repeated full discharge/charge cycles on the cells to restore worn out cells. It has a display which shows the milliamp hours in and out while cycling. Guess what? It works! With each cycle, one can see the capacity of older cells increase, often to like-new condition.

Mike:
The figures I mentioned were obtained from Honda's own DVD based technical literature. I also have the paper volumes as well as some access the channel's tech bulletins.

Tim may be right in that we may have been referring to different thresholds. The range I mentioned is the target (or optimal operating range) of 60% to 80%. The "managed range" is wider than that and it would represent the "absolute limits" as Tim mentioned (thanks Tim).
I'm still looking for an explicit reference on the material I have available to me as to what the exact absolute range is. But as a "guess-timate" I would say that it begins at 40% to 50% (???) on the low end as well. I believe other HCH-II owners can/may also help me validate this figure as well through their own experiences.


Cheers;

MSantos

Something else I've heard: it has been suggested that batteries have a "break in" period of their own where efficiency increases somewhat during the first part of their life. Any truth to that?

Hummm...

I can't say if I heard of that before.

If I recall correctly, in all the literature I've been reading on the subject over the years, I have never seen any references to a change in the NiMH operational profile that indicated a positive trending break-in "period". All the data I have seen seems to imply the opposite when plotted as a function of time from the day of its manufacture.

Then again, maybe it is time for me to send this question through to see what kind of answer we get back.


Cheers;

MSantos

I can't say if I heard of that before. I read somewhere that NiMH batteries may take a few charge/discharge cycles to exhibit their full capacity. Not sure where- might've been on a pack of AA NiMH.

I think Brick is correct.
I was under the impression that 80-20% was the absolute range that the IMA will allow, not the range that the IMA tries to stay between so we were talking about different things.

A related thing I have been thinking about lately:
The SOC calculation is based on the bipolar current probe on the IMA battery pos leg. MIMA taps that sensor to generate the amp bargraph.

The sensor is powered with a +12 and -12V supply from the BCM. Zero current is mid point between the two supplies, and corresponds to the neg leg of the standard 12V system.
As part of the MIMA install, we measure the two supplies. Most are exactly +12 and -12, or 24V between them.
I have seen some variation of this voltage on several Insights, with +11.8V instead of 12 on one recent Insights current detectors supply. If that slight offset was not corrected in software, it would bias the SOC slightly to the regen side, and could accumulate and cause the actual SOC to drift.
Unfortunately I did not record which Insight it was so we could see if that car has recals or other battery related issues.

Just got a call from a guy in CT with a 165K Insight that has an IMA light, and is facing some big repairs. He will drive up for this Sat hybrid workshop, and we may have another problem pack to play with to add to our information.
If there was a requirement for cycling the NIMH batteries, it was probably done before installing in the car as part of the cell balancing they must do on a new pack.

Part of the problem here, of course, is that the string is
being monitored at a granularity of 12-cell blocks. [That's
right for the insight/civic D-cell pack, right?] Like the
Prius, as well. But if one CELL inside there starts to go
south, that's going to throw off the whole measurement for
that pair of submodules, and the BCM is going to throw a
fit and start doing what it can to try and realign its own
conceptual limits. A full cycle, similar to an "equalizing
charge" done on big strings of 12V lead-acids in gear like
big UPSes or PV systems, helps bring the cells in line with
each other again, but it's a really brute-force way to go
at it. On the bright side, slightly overcharging neighboring
cells once or twice lessens the possibility of *reverse*-
charging the one questionable cell, which will likely kill
it. The only real fix here is per-cell monitoring and
possibly even some clever electronics wrapped around each
one to help re-eqalize on the fly when needed -- lithium
chemistries need that sort of thing even more, since straying
outside their limits is even more serious. But that's a lot
more investment in control electronics, so here we are at
the twelve-cell level.
.
But the general inability to look in any closer leads to a
lot of guesswork about what's really going on. Hopefully the
take-the-pack-apart work that Mike and Ian are doing will
turn up some useful info on "reconditioning". I'd like to
see some of that actually go down to the cell level if
possible -- with the Honda packs you can stick a probe through
the tube and get at the outside of each cell's case. That
would be a lot harder on a Prius subpack, but those have the
advantage of somewhat updated manufacturing and seem able to
keep the cells more aligned with each other in the first place.
.
_H*

Part of the problem here, of course, is that the string is
being monitored at a granularity of 12-cell blocks. [That's
right for the insight/civic D-cell pack, right?]

Correct.

For example HCH-II has 11 monitored modules at 12 cells per module. And you are quite right... even if just one cell goes bad, it is enough to place the SoC anywhere in the map (depending on the failure's characteristics). Knowing which module that cell is in helps, but neither Auto manufacturer supports disassembly and repair on a per-module basis. So far, it still boils down to an "all-or-nothing" affair in that the service outlets simply replace the entire pack.

Sometimes I wondered, if hybrids continue to proliferate at a good rate, perhaps there'll be a small market with few shops popping up here & there that will recondition whole battery packs - particularly for out of warranty vehicles... all on the account of replacing just a few bad cells. I would see reconditioned packs going for much less than $1,000 when bought as replacements, and a few hundred ($300-500) when repaired.


Cheers;

MSantos

Hi All:

___No guarantee’s yet but Laurie’s HCH-I appears to be normal …

___Sean brought the SoC down to 1 bar from 15 while leaning on IMA heavily over the first 50 miles when heading down to Milwaukee late last night and early this morning. At 1-bar she was still assisting and regen-ing so the BCM appears to have lost track of actual SoC while IMA allowed both at a SoC that should not have been possible if the measured as shown per the SoC display was actual. That was weird? Anyway, from 1 bar, she came up to 17 of 20 bars and hung for the rest of his drive to Bradlee’s. 6x.x mpg to show for the effort. Sean drove from Bradlee’s to the meet at 70.0 mpg this morning.

___I took it out this afternoon and Assist was acting just as it should. A light touch and she blasts it out. Back off and bring her back online with a touch of accelerator and she comes up without a bar of assist while holding 17 of 17 bars of SoC. My 10 mile mostly highway segment yielded 72.6 and she showed 17 of 17 when we stopped. Bradlee and Sean pulled the 12V, forced a recal, drove it for maybe 5 miles of highway and she came up to 20 bars from 0 and held. One last hill dropped her to 19 of 20 and that is where she sits. We will know more tomorrow after Sean gets back home but everything appears to be working just as it should both before and after the forced recal.

___Good Luck

___Wayne

*fingers crossed* I really am hoping this works

Wayne
Interesting test, it will be interesting to see the results.

Just to keep things clear, what you are calling a forced recal, is really a computer reboot, nothing like a SOC quick drop recal with 12V active. The SOC does a positive reset up scale once it determines that it knows approximate SOC.

I started a battery pack thread on the technical forum, as this is off topic here.
Good luck with the car.
http://www.cleanmpg.com/forums/technical/t-battery-pack-care-and-feeding-7026.html#post51883

Hi Mike:

___IIRC, a recal is caused when the BCM sees a large enough difference between perceived SoC and a calc or map. A forced recal does the same. The BCM in each assumes/calculates the SoC is now at some minimum and forced charging occurs over the course of 3 - 5 miles to bring the pack back to a “known” high SoC condition. The SoC dance seen is exactly the same as I have seen in Randall’s and Justin’s Insight’s during their recal’s other then that one is forced vs. Honda’s own algorithms attempting to place the pack back into a known SoC. SoC drops to 0 and forced charging occurs to bring them back to this ~ known “SoC”.

___By all appearances, Laurie’s HCH-I BCM needed to more closely match actual SoC. The Assist at 1-bar is a telling sign that the BCM calc was skewed down the scale to some extent knowing how the Insight 5-speed and CVT’s as well as HCH-I’s w/ CVT’s act wrt a minimum 6 bar SoC when all assist disappears.

___Let us hope so for Laurie’s sake anyway?

___Good Luck

___Wayne

Hi All:

___No guarantee’s yet but Laurie’s HCH-I appears to be normal …

___Sean brought the SoC down to 1 bar from 15 while leaning on IMA heavily over the first 50 miles when heading down to Milwaukee late last night and early this morning. At 1-bar she was still assisting and regen-ing so the BCM appears to have lost track of actual SoC while IMA allowed both at a SoC that should not have been possible if the measured as shown per the SoC display was actual. That was weird? Anyway, from 1 bar, she came up to 17 of 20 bars and hung for the rest of his drive to Bradlee’s. 6x.x mpg to show for the effort. Sean drove from Bradlee’s to the meet at 70.0 mpg this morning.

___I took it out this afternoon and Assist was acting just as it should. A light touch and she blasts it out. Back off and bring her back online with a touch of accelerator and she comes up without a bar of assist while holding 17 of 17 bars of SoC. My 10 mile mostly highway segment yielded 72.6 and she showed 17 of 17 when we stopped. Bradlee and Sean pulled the 12V, forced a recal, drove it for maybe 5 miles of highway and she came up to 20 bars from 0 and held. One last hill dropped her to 19 of 20 and that is where she sits. We will know more tomorrow after Sean gets back home but everything appears to be working just as it should both before and after the forced recal.

___Good Luck

___Wayne

THANK YOU BOTH!!! :)

You are very welcome, Laurie!

As far as I am able to determine, the problem was resolved. I played with it all the ~360mi home and I kept the majority of that distance with an absolutely full pack. It was only about 30F or so for the trip so lean burn was out, and the SOC stayed on 20 bars. It would drop out if any assist occurred, and I did run it down to 18 bars once. Background charging then brought it back up to 19 as it should and it didn't go back to 20 on its own... though I was able to regen back up to 20 and it did stay when I hit that value?

Other than that, perfect behavior throughout. I told Laurie about this yesterday when I returned the car and conjectured that 20 would be unattainable after the SOC had been exercised a little lower than I had pulled it. I'll be interested to hear whether you are now unable to regen to 20 bars, Laurie?

The car gets my special Sean seal of approval. ;) Not that it is worth anything much...