I know this thread is a month old, but my guess as to how to kill the pack: put in a crappy 12V battery and run it that way full time. You'll have to jump start the car every time, but the HV battery will have to work a lot harder to keep the dying 12V charged.

 

Yes I'd second Bob's recommendation. Since our cars lacks an alternator a bad (or near bad) 12v battery will work the IMA a lot harder than a good 12v battery would. Since like Bob said the IMA would be constantly recharging it..

 

do not drive the vehicle. everytime you drive, the car has a chance to charge the ima battery back up to a reasonable level. batteries do not like to be depleted so by not driving the car is the only way to let the nimh cells self discharge. This is also why you probably, after leaving the car sit for a couple days, will notice it is a little harder to start. This is because the ima computer says that the voltage in the ima battery is too low to start your engine so it starts like a non hybrid car from the 12v battery. I am letting my car sit as i am at 80,000 miles and hope after letting it be off for an entire month the voltage will be low enough upon starting it that it will "throw a code" wish me luck, good luck to you. RECAP: If you want to kill your 12v, leave the lights on. If you want to kill your 500V, let it sit.

 

I don't think its going to happen! That is why it has a back-up starter? H

 

In checking the IMA battery voltage at the terminals on the IMA battery (cover off, determining how a grid charger would attach), I found that a full charge on the IMA battery according to the dash gauge was 189-190v. At "half" charge on the dash gauge the IMA voltage was ~171v. Both of these are much higher than the 158v nominal voltage the pack is rated for.

I've also noticed that my IMA battery is crashing once almost every trip to work now (23 mi each way) regardless of ambient temps. At this point heat isn't an issue up here. Generally, the IMA has recovered from 2 bars to entirely full within 3-5 miles though and as short a 3 minutes.

 

I think the best solution if your a big **** HCH has a IMA light on or when you have a lot recals per day.... Sell your car ASAP and Buy a Prius or bicycle and don't deal with Honda anymore...
I have HCH 2006 and with just 65 k miles and it's acting like a peice of **** now (IMA and malfunction light on + 10 recals/day), I prefer to have hyundai getz 2010 now better than this crap..
The big problem that I bought my car from USA and shipped to my country, the amazing thing that my local honda dealer doesn't recognition of Hybrids at all !

 

dwichman... In April of 2010 my 2006 HCH with less than 25K started having the same symptoms you have now. The first thing the dealer did was apply the latest software. The newer software makes the IMA system work differently. Things went from bad to worse. At times there was no IMA assist, which made the car dangerous to drive, plus all the other symptoms worsened significantly.

The IMA battery was "marginal" but not bad enough for Honda America to agree to replace it under warranty. The dealer kept the car for a few days. They agreed it was not operating like it should but had not received authorization to replace the battery.

The service manager brought up my situation when the Honda America regional rep was on site. The bottom line was that the battery was replaced gratis. It was the dealer going-to-bat for me that made the difference. Parts and labor were $3,085. Since then all is good and I get around 44mpg.

BTW - Page 213 of the owners manual states: "NOTICE If this vehicle is unused for over one month the service life of the 158v battery will be reduced and may be permanently damaged"

The mechanic said that I may not have driven the car ENOUGH yet it never sat for more than a week all the time I owned it. Someone could be in real trouble if they purchase a used HCH II that had been sitting for an extended period.