Hello Guys,

First time poster here. I purchased a 2007 with 75k miles in July 15. Did all the basics, oil, tranny oil, filter, brake fluids etc, it has been getting 40ish in the city traffic with less than optimal driving habits, I have been happy with the mpg esp. coming from a lifted 4runner

Last night I got the check engine light, followed by IMA light which disappeared after couple of hours. My OBD reader tells me it is a P0A7F code. I can perform quiet a bit of car work and do not mind tinkering with stuff, also being an electrical engineer (although in software) I feel I should be able to disassemble the pack and replace the bad cells without killing myself or perhaps build a grid charger...

Given my background can someone direct me? what are some of the options

Is the warranty 8/80,000 or 9/92,000 and should I contact Honda NOW?

Purchase a grid charger (like max volts) or build my own, I live in Atlanta and Grainger is within driving distance?

Disassemble the pack, identify bad cells, replace?

Other options?

I will continue to read but in the mean time can someone please direct me

Many thanks

 

Just talked to a local Honda Dealership and good new is that my car still has 1 year and 10k left miles on the battery replacement BUT first they will do a software update on the vehicle

 

9/92K You should be covered if you're under 92k. Go straight to the dealer and do not reset codes.

 

Thank You Steve,

Although it took them three hours but they are replacing the battery under warranty, the rep told me that my vehicle already had the updates and they could not get rid of the codes.....I will report back when I get the car back

For the replacement what kind of life I can expect, also I guess this would be a good time to start looking into grid charging?

 

It always takes them forever to get authorization

The replacement battery will have no warranty beyond your 9/92. They are notoriously sh1tty. 2-3 years will be a good run.

As soon as you are out of the warranty period, grid charge 24 hours at every oil change.

I do not recommend MaxxVolts products. I believe they are a quality unit, but he is behind the curve on the technology. It has been demonstrated repeatedly that discharging is also vital to maintain pack health. Excessive grid charging can actually make voltage depression worse. Voltage depression is the primary reason that IMA packs go imbalanced and lose capacity.

I recommend Hybrid Automotive "discharge ready" units. You can build or buy their discharger (nothing more than a light bulb socket, DVM and a custom harness). Note that those harness components are expensive. I've bought them for my own charger builds, so the price he's asking isn't outrageous at all.

If you want to save a LOT of money, you can check the DIY version on my sig, but you MUST remove the pack from the car as I can't drive the 12V fan as it requires a PWM signal.

Thanks,

Steve

 

They have given me a rental so hopefully they will be quick, its a bummer about the replacement batteries as I was/am hoping to keep the car longer than 3 years.

I found the BOM and I will build one, I am sure the wiring diagram is lurking somewhere on the forums. May I ask the 145k and 222k on your 06s, is that on original batteries that you have been maintaining via the grid chargers?

 

Oh God no... both of mine are on at least their 3rd pack, and I have a total of 4 packs between them with 6 total sets of sticks. I have engaged in both grid charging and stick-level refurb with varying degrees of success.

IMHO, the new sticks are less reliable since Panasonic divested their equal interest in Primearth. Now Toyota owns 80% and is exclusively focused on their prismatic modules. '09-10 pack reliability has been atrocious with 30+% pack replacement rates as of 2013. I have no data for the 2011. It's so bad, Honda extended their SULEV warranty (10yr/150k mi) to ALL states.

Given everything I've done, whole pack grid charging and discharging is the best bang for the buck BY FAR when you consider the "bench-time" investment. I'm currently in the process of "sorting sticks" based on as-removed performance, i.e., I build a pack, run it for a bit until it recalibrates, or I get an IMA light, break down the pack and discharge the sticks at 20A. It's usually one or two pairs that have notably lower capacity than the rest, and it's usually because 1-2 cells in those sticks (pairs of sticks) have excessive self-discharge. I can cycle them and restore them to near 90% capacity, but they won't hold it.

Check the "Wiring" tab on the google sheet.

NOTE: YOU MUST PULL YOUR PACK FROM THE CAR to use my charger or devise your own PWM controller. When you've done it a handful of times, you get really good at it. I can do a complete swap in 15-20 minutes.

Steve

 

Taking the pack out and wiring looks simple enough so I will be following your advise on whole pack charging/discharging.

Some additional questions if you do not mind:

So if I wanted to build a spare pack which I can charge at home what is the best route, does keeping an eye on craigslist for totaled civics, insights, accords is the way to go?

What is the compatibility of the individual sticks form these cars (what years are compatible, 06-11?); also can we scavenge sticks from Toyota as well?

Why can we not build our own sticks with Industrial Grade D cells, are they not available in the market?

Steve thank you so much for you valuable input, I do really really appreciate it

Have a great thanksgiving

 

00-06 insight and 03-05 Civic use single sticks. Civic sticks are better, so best to upgrade an insight pack with civic sticks.

06-08 civic only compatible with 06-08 civic
09-11 civic only compatible with 09-11 civic

05-07 Accord sticks MAY be compatible with 06-08 Civic, but I can't confirm.

2010+ Insights and CR-Z MAY be compatible with 09-11 civic, but I can't confirm.

Toyota uses prismatic modules that are in no way similar to Honda IMA of any kind.

In short, your only guarantee of compatibility is 06-08 Civic. Craigslist, local salvage yards, etc.

Fabricating your own modules is astoundingly impractical. Beyond questionable availability of cells, they must be welded together in a very specific way. Simple contacts are not sufficient to handle the 100A load.

If you want to pursue partial fabrication, you could get 6 cell sticks from China and devise a means of attaching them to create a pair. I believe that's what the current battery builders like Bumblebee and Hybrid Revolt do. You'll probably be into it for $1400 plus your time. At that point the replacement packs from bumblebee/Hybrid ReVolt look really attractive at $2100 or so with a 3 year warranty you can trust.