Bought the 2005 Accord Hybrid in early 2005, and it’s been a typical, trouble free Honda except for a software update in the first year to correct a check engine light which appeared.

Nearing 150,000 miles, the Check Engine and IMA warning lights both came on in December 2011; start battery was over 3 years old, so I changed it, and that reset the trouble lights for about a month when the check engine and IMA lights reappeared. Took it to dealer who reported this fault code:
DTC POA 7F, Battery Module Deterioration. Tech said there had been further software updates and that he’d like to try that fix before replacing the IMA battery. Did the software update and all was well for about 400 miles when the check engine and IMA lights returned.

Took it back to dealer; tech read same fault codes, consulted with Honda, and recommended replacement of IMA battery. Cost $2309 for battery, $141 labor; total was $2762 after taxes.
Actual miles at time of IMA batt replacement: 148,788.

Hope to get another 100k miles with this IMA; car still getting 30-34 mpg regularly on average, with mix of town/highway miles. No other issues.

Lewis

 

The start battery is actually the 144V IMA battery.

Wow, labor was cheap! I'd expect more for IMA battery replacement. I can't believe seven years later the IMA batteries are still so expensive. The estimates back in 2005 was that by the time the IMA batteries would require replacement, they should cost less than $1,500, including labor.

Glad to hear your car is back to normal.

 

I'm betting those estimates were assuming that Honda would still be making the HAH. Greater supply would mean lower costs.

But that didn't happen.

 

Edit: on repair history
In 2006, had the "harmonic booming" problem from the ANC (active noise cancellation). Thanks to this list, I was pointed to a TSB on the issue. No "booming" sounds since dealer repair.

Some further details on the IMA/Check Engine issue:
My response to the first warning lights (I was about 15 min from home) was to drive slowly and park the car (I'm 40 miles from a Honda shop) and do a web search. Lots on Civic Hybrid batt replacement, but found some on Accords, including the recommendation to check the 12v batt first, or at least disconnect it which removes the warning lights. My 12v was over 3 years old, so I replaced it, and the IMA/Check Engine lights went away, but returned after about 15 minutes of moderate speed driving (under 60mph). I disconnected the 12v again, clearing the warning lights, but again they returned after 10-15 minutes of driving.

At least one post outlined what eventually happened to me after trying the 12v fix: software update fix attempted, warnings returned with DTC POA7F (battery deterioration), finally IMA batt replacement.

After the 12v batt fix attempt, I scheduled Honda shop visit and watched everything closely on 40 mile drive. I noticed no change in overall performance; in fact, got 36 mpg because I drove 50-60 instead of usual 65-70. Makes me think that the car was going into 3 cylinder mode even though the ECO light never came on.

Irregularities noted during drive: "ECO" light never came on; IMA batt bars varied notably--it would be at 6 bars (seldom above 4 bars in normal driving, almost never 6), then the blue IMA assist indicator would come on and off for awhile, followed by the IMA batt bars dropping to 1 which called the green charge indicator light to come on, and the IMA batt charge would gradually rise to 4-6 bars. This pattern repeated 2-3 times in the first 20 miles, then the IMA batt bar settled on 4 for the last 20 miles. I could feel some slight power surges when the IMA blue bar came on (not unusual). In town, I noticed the Auto Stop feature did not always work even though the IMA batt charge showed 4 bars. IMA batt charge level fluctuation and recharging and absence of ECO light the most notable irregularities.

About 200 miles since IMA batt replacement with typical mileage and no irregularities so far.

BTW, the new IMA batt came from Honda in a hardshell box which the tech put the old batt in for return to Honda. Took a photo of the batt in the box though there's not a lot to see.

Lewis

 

Cubcup, agreed. But that's still not even true for the more popular HCH. Their batteries are still rather expensive. I've always wondered, if they (any auto manufacturer that makes hybrids) made the battery pack user replaceable, that more folks would have not only bought a hybrid to begin with, but would periodically replace their batteries on their own. This would have definitely driven down costs, given supply.

Lewis, all you're doing by disconnecting the 12V battery is clear the fault memory. And, as you saw, after the car ran it's diagnostic checks, it would again set the fault codes and accompanying fault lights. Doing as you did, and cleared the fault codes, helps to determine if the fault was a fluke from some anomaly. But just as you did, when the fault reappears, it's time to get it checked out. Pulling the fault codes is relatively easy. Just takes a code reader, which can be had for cheap. Or, for free, if you take it to most auto parts stores. Generally, armed with the fault codes and google, it's easy to determine what's wrong with your car.

I'm glad to see your car is back on the road.

Any chance you can post pics of the batteries?

 

Photo of 2005 Accord IMA battery partly packed for shipping to Honda.
Lewis

 

See, that looks pretty simple. Wish they made it an easy user replaceable item.

 

I've always said that the future in electric cars is to run them like the propane tanks for your gas grill. If you run out of juice before you can get home, or you're on a long trip, simply bring the car in, trade out your spent battery for a charged battery. Give the guy $40 and off you go for another 200 miles.

If they can make the batteries in cartridge form, it would totally work. Wouldn't even have to build the infrastructure. Current gas stations could just install a battery charging rack...

 

Thanks for the great info. My HAH had 169k when I bought it mid-August 2011 and now I'm up to 185k, so I have been expecting the same routine at any time now.

Does anyone know of a way to determine if my HAH is still on the original 144v battery pack or if it's been replaced? Mileage seems a little long to be original, but how would I know?

 

For my two Hondas (05 Accord Hybrid, 03 Pilot), the service record is in a database by VIN. Any Honda service shop should be able to access all Honda shop service on any vehicle you own, whether you are original or used vehicle owner. I bought the Pilot used from a Texas source, and I can tell what Honda service has been done from time of sale to present from my local Honda shop. Or, so I think. Ask a Honda dealer the next time you have your car in for service if you can view the service record.
Lewis