Hi everyone,

I am considering purchasing a nicely maintained 2005 Honda Accord Hybrid with only 28,000 miles. As far as I know, the hybrid battery is still functioning well and there are no mechanical issues with the car. My questions are:

1) What wears down the hybrid battery, miles driven or the passage of time? This car is 9 years old, and from what I can tell hybrid batteries generally have a life of 8-10 years. Does the low mileage on this car counteract that at all, or is the battery at some point going to fail no matter how few miles it has on it?

2) If I take the car to a Honda dealer, are they going to be able to provide me with any information on the battery outside of either (a) it's working fine for now or (b) it's not working for now. For example, can they tell me that it's working at 80% of it's optimal state versus 20%, so I could have some kind of clue how long it will last before needing to be replaced?

I think it's a nice car, but at this point I'm thinking I basically need to subtract $3,000 from the asking price to cover the cost of a potential replacement battery. And then if I ever sell it down the road, the next person may want to do the same. So despite the normal Honda reliability, I'm a bit concerned about how well this hybrid will last going forward.

Thanks for any thoughts!
Erik

 

My 2005 Hybrid is 125K, the battery is starting showing its age. With nearly 100K less, I guess the battery of the car you were considering should still last a few years.

If you take the car to Honda dealer, they won't provide much info on the battery side, because the car's computer says the battery is working normally. Unless the batter is taken out and each battery cell going through thorough test, not much info can be obtained.

 

At this mileage, I wouldn't be worried about the battery state. It is most likely good and still have lots of life left!

FYI, battery is based on state of charge and drainage cycles exclusively.

The life of the battery really depends by these factors:

1) How many healthy drain and charge cycles it elapsed? The more cycles, the more batteries wears out.

2) However, above not always true. If the battery INSTEAD are not "actively" cycling, in fact the situation could be much worse and less healthy than the point 1) above. Battery cannot sit idle for long time especially Ni-MH vs. LiOn ones. If battery is sitting (which in your case, I could have been), then it could damage the battery. However, no fear...a few drain/recharge cycles should be able to "train" the battery back to a rather healthy state. Then you can tell if the batteries are going bad or not based on how fast the battery drains.


Having said that, with mileage so low like that, the best thing is to drive it in CITY for...say half hour. You can INITIALLY charge the battery to full by wasting a bit of gas after the car warms up. When car is at normal operating temperature, park your car, shift to park and simply "rev" your V6 to around 3-4k RPM...hold onto your accelerator for about a minute or so...during this time you shall see the "Charge GREEN" bar lighting up meant it is charging your battery. When you get 6 full bars, then your battery should be near or fully charged. Then shift out of park and start driving. I suggest you do this in the evening when traffic is relatively lower.

Drive around, accelerate to legal speed and CRUISE with "ECO" on running on 3-cylinders. Then when this is smooth sailing, just press the accelerator a touch harder delicately and you will see "Assist BLUE" bar light up meaning it is assisting with the IMA motor. Let the blue bar light up in full and the battery will smooth drain down till it hit the low 4-bars will which the system will NOT assist anymore and back to "ECO" mode. Below 4-bars or lower of the 4, assist with the motor will be very sparingly and only very sensitive foot work or running downhill will you get more assist.

Then next you will want to charge the battery from 4-bars back to 5-6 bars again. You do that by accelerating enough always out of ECO mode...drive a bit faster than legal speed and then relieve the throttle so that you naturally let the car decelerate and let the system's regenerative system to charge the battery back. Let off the accelerator as long as possible to maximize the effect. If speed is lower than legal...do the same cycle again till you get 6 bars. If a stoplight is ahead...even better...you simply just nudge the brakes just enough that you see a FULL GREEN bar and NO MORE than that to maximize charge while you maximize rolling distance.

Do all that 4-5 cycles and you should have a good idea if the big hybrid batteries are holding charge and draining well.

Hope this helps. Feel free to ask any other questions.

 

I need to disagree with a couple things. With regard to Honda packs:

* NiMH battery capacity deteriorates at about 1-2% per year.
* NiMH battery capacity deteriorates slightly with heat cycles. It can deteriorate significantly with heat cycles in environments like AZ summers.
* NiMH battery performance deteriorates with extended periods of sitting followed by infrequent driving, e.g., park it for 2-4 weeks, go for a short drive and then park it again.
*Months long extended sitting can actually improve pack performance as self-discharge tends to equalize the cells at a lower state of charge. However, efforts to fully charge the battery after extended sitting should be made. I recently installed a pack that sat for 2.5 years. As-removed it was performing poorly and threw IMA lights. It self-discharged to an average of 0.45V/cell (59.6V pack). I cycled sticks 3 times and saw no improvement in performance with all sticks testing at 90% of original rated capacity.

The worst thing you can do to a pack is place a heavy demand on it when some cells/sticks are at extremely low states of charge whiles others are at a high state of charge, and the car thinks the pack as a whole is okay. I have a simplified method to maximize capacity:

Obtain radio/navigation system security code for re-entry after 12V disconnect.

:loop

Disconnect 12V battery for 1 minute.
Reconnect 12V
Start car
Idle until the meter indicates charging. Rev to 2500 rpm and hold until SOC shows 100%.

repeat :loop 2-3 times. When the car thinks the battery is full, the recharge period will be extremely short. This is essentially the same as tedson99's initial recommendation.

Drive the car normally.

Tedson99's other recommendations may be worth pursuing as it does appear to provide some significant discharge and demonstrate performance during cycling. However, I feel my technique of maximizing charge is important to restore battery to the maximum state of charge possible.

Steve

 

Thanks Steve for correcting and elaborate more towards my answers.

It sure will help everyone here.

Hope all this helps in this thread.

 

Hello...latest update. I recently got the nasty IMA, Battery and Engine light ON.

I did the looping like Steve mentioned and have been doing well since.

Looking like a false alarm...so far for me. The behavior is feeling normal as before.

It is around 10-20 Celsius here in Toronto ON Canada and I am getting around 9.4L/100km for the past 1000kms travelled mainly in City driving...trying to maximize ECO mode and keeping the battery above 2 bars.

From time to time due to stop and go traffic, I cannot help it and the battery went out of juice preventing me from AUTO STOP.

 

Per the other thread... look into grid charging... could get you years of continued service...

Steve

 

Thanks S Keith.

I am not sure how to drive this HAH anymore to keep my battery healthy longer.

The way I drive is always trying to be in ECO mode and when my Accord want to assist, I will let it and maximize it till it can no longer do it.

Not sure if this is a good idea as I am high-draining the battery this way and promote cycling a lot more than if I let the engine do even more of the work instead of motior assisting.


What do you think? Should I promote my Accord to assist me LESS now that the battery is getting older?

Again, can you tell me exactly how I can practice GRID CHARGING.

Thanks.

 

Mind you actually...I am actually not sure if 9.4L/100kms is a good fuel efficiency number for the HAH anymore.

Spring had really just started a week or 2 ago here in Toronto ON Canada...prior to that I am certain the WINTER ADDITIVES in gas station and the use of my WINTER TIRES, PLUS the COLD will affect my mileage. However during the worse of winter, I never went over 9.8L/100kms on average.

Now that WINTER GAS is out, and the normal GAS formula should be in replace, PLUS I have summer tires now....my mileage should fall below 9.0L/100kms

I have driven this car to a low 6.1L/100kms on highway before...and around 8.9L/100kms in city.

Oil change is due in about a month's time (down to 20%)...after the service, I will reset the gauge and see if I can get these old numbers anymore...

What do you think about these?

 

The more you utilize the Hybrid related systems, the more cycles you put on your battery. More cycles = faster deterioration.

Conservative acceleration and deceleration is the only thing you can really do to minimize impact to the battery. Less full assist and less full regen are less taxing.

Grid charging: Get a discharge ready grid charger from http://www.hybridautomotive.com . Buy or build yourself the discharger (recommend dual bulb). You'll be out around $500, and the DIY installation is very well documented.

Concerning economy, I don' t have a feel for the HAH, and I only speak mpg. 40 mpg is 5.88L/100km, so I would expect your numbers to be near there at the warmest time of the year. 6.1 probably isn't too bad at 38.5mpg.