I am only guessing (like most of us) but one possible answer could be that yours is an '09 with fewer miles. Maybe batteries with more miles (use) start to expose weaknesses in the IMA design and /or programming. I've not yet had the upgrade, but our car has certainly had declining mileage and increasing recals / flat IMA charge as it has gotten older (now at 55K miles).

 

if the functionality of the old software contributes to a shortened battery life? I quickly skimmed the Honda letter, but it seemed to indicate that the old software wasn't optimizing battery life.

Am I paranoid?

 

The Nickel Cadmuim battery pack by design will function less well over time until it cannot be functionally recharged. The software does a number of things if you read your letter, but it also decreases the chance that Honda will have to replace a hybrid battery pack that really needs replacing.

Some have said that it circumvents key codes such as check engine and IMA battery codes from illuminating by intent, so that a warranty claim wouldn't be substantiated for a replacement hybrid battery pack.

The life of the battery pack does vary based on condition and use, but nickel cadmium batteries recharge better and last longer if they discharge all the way down and are then recharged.

The CEO of Ford has pretty clearly outlined the lack of cost effectiveness for this type of Hybrid for a car company, and I do consider it an interim technology. I know for me and my car that the battery pack will likely require exchanging at about 50,000K per battery pack.

One possible solution is for Honda to design/acquire a Lithium replcament that will last longer, but heat production and fire hazard from this type is a major problem.

I will likely drive my HYbrid another 4 years or so, and assuming the dollar has any worth at that time will buy an electric car most likely. The Nissan Leaf and Volt are not horrible offerings for a start and perhaps in 4 or 5 years we will have more choices too with a little longer range as well.

 

My battery pack was replaced under warranty right at about 55K. IMA light had just come on.

 

FYI-the chemical composition of the battery pack in all of the current Honda hybrids is Nickel Metal Hydride, or NiMH. NiCAD batteries would never last in a hybrid car as they absolutely have to be drained completely, and then fully charged completely each cycle, otherwise they will memory effect very severely (that is, remember that capacity that was utilized, and only have that capacity going forward.

NiMH greatly reduces memory effect over NiCAD, but does not completely eliminate it, which I believe is partially the problem that Honda (or any Hybrid Manufacturer) is dealing with.

Realize the main pain in the these battery packs in it isn't just one big cell (that would equate to an unuseful 1.2 Volts nominal, that wouldn't even light a white LED!), but over hundred individual cells connected in series to bring the voltage up to useful 144V in the HCH II, each with individual behaviors of their own. If a single cell goes bad, or even loses its capacity faster than the other cells, then the whole pack suffers. The bad cell will act as a giant resistor, and overheat as the other cells try to power through it.

Question is how often is it likely that a single cell heads south? Well, I have many devices in my house that take AA batteries (xbox controllers, wii controllers, etc., kids toys, etc). I've made an investment in a Powerex AA battery charger that actually tells me how much charge that battery is taking in milliamp hours (mAh). I've found that Kodak and Energizer makes some of the better rechargeable AA's...new they will charge up to 2700 mAh easily. After 30-40 recharges, they settle into around 1800-2400 mAh. Thats not bad for capacity, but a lot of variance.

I've noticed a more worrisome behavior though with these NiMH cells that I would have never caught with my original cheapo charger: occasionally I have a controller that during game play that dies suddenly and prematurely even though I just pulled the batteries off the charger and it showed near equal charge on the two. I'll then recharge the two batteries that were equally charged in it prior, and i'll find that one of the cells will only take 800-1100 mAh. Weird. So I run the misbehaving cell through a refresh cycle once or twice and it brings that it back up to 1800-2100 again.

Now I know these are "consumer grade" batteries, and hybrid manufactures go through great lengths to make sure that all the cells in a battery pack are high quality (hopefully ) and balanced, that is, contain equal charge. BUT, i do a similar process with my AA's cells before I stick them into the same controller, and every once in a while, run into an errant misbehaving cell.

Kind of makes you go hmmmmmm. Would definitely explain why a few people have issues, and some do not. Would definitely explain why the ECU has such a difficult time keeping track of state of charge, and the entire battery pack suddenly "crashes" because the ECU thought it had put a bunch of charge in the entire pack, but a single cell is holding back its potential. Would explain why throwing software updates at the problem isn't fixing anything.

The HUGE question that I have is, what process does Honda have to detect and correct this situation and do they actively use this process? I purchased a shop manual for my HCH II, and THERE IS A process described to manually measure the voltage of different "sticks" of the battery pack to look for variations in the entire cell (a stick, i believe, being 6 cells in a string). This would certainly help pin down if there is an errant cell somewhere in the pack.

If I weren't still under warranty and was afraid Honda would void my warranty because I cracked open the pack (even though it would be per the same instructions the dealership should be following), I'd be very VERY curious to see what variations there are in the entire pack and do the diagnostics myself.

Another question is can the ECU even physically read these individual voltages and make diagnostic decisions itself, or was that a design sacrifice to reduce cost? Or if it can read these varied voltages, how have the thresholds of declaring a bad battery be set or changed over the multiple software updates they've released?


FYI: I also...discovered that I do in fact have the full recall update on my car, so back in it goes, already had two battery crashes since it was done.

 

Why yes-- thanks for the correction on my bad info on the NMH battery description.

The Hybrid battery pack was described to me as similar to a 100 D batteries strapped together a ways back - and then along similar lines as you are saying - "grouped cells"

I had some faulty cells in the pack - and got the whole thing replaced under warranty fortunately before the software update was available.

Some aspects of the update appear to exist for the purpose of covering up the ability of the check engine and IMA lights and codes to be expressed so as to lessen the instances were a warranty replacement would occur.

The profitability of the car is dinished or goes away when a battery pack needs to be replaced so the financial motives are quite clear in this instance.

 

I've taken the car on a few jaunts around town and can share only initial impressions.....

First of all, it was warm today (85 degrees) and the car seemed more responsive--particularly from a stop. I noticed that it made it up a steep incline without difficulty and DID not entirely drain down the IMA to 1 or 2 bars as it used to.

Hard to explain, but the car seems more drivable to me. Nothing scientific, but it seems peppier off the line and during most accelleration. And, the battery seems to recharge faster, too. It's almost too good to be true.

Just an initial impression. More later...

Anyone else??

Lansing

 

yeah. I think the hch2 has 158V battery pack.

anyways, I got these links a while ago that explain a bit

http://www.cleanmpg.com/forums/showthread.php?t=24829
http://www.cleanmpg.com/forums/showp...56&postcount=4

ks

 

The notice people are getting states 2 factors that might explain this:

1. Assist is used a little less, and stopped a little sooner. <less demand

2. The display of state-of-charge is being shown as being higher, compared to previous. <rosier picture

 

Had reflash 10-034 done last week after receiving a call from Honda to be checking for the mailing. Too early to be certain of improvements to my '06 HCHII. I've passed 70,000 miles on it with FE ranging betweem 43-48 with road trips reach above 50mpg. Except for the spoiler paint problem, I've had no problems.