[Dr. Ali Fant]

My IMA main battery failed and was replaced as noted elsewhere in this forum.

I immediately noticed a reduction in available Main Battery charge capacity. True, the battery could be fully recharged by racing the engine above 4K RPM. However, this wastes gas. Previously, normal driving kept the IMA battery fully charged.

I verified that the car no longer has regenerative braking down to the original specification 19 MPH. Now, the computer switches off the charging system when the braking speed drops below 29 MPH. This 10 MPH difference accounts for the lack of charging to 80% capacity.

I contacted my dealership and he verified that Honda has decided to make ALL replacement IMA batteries with a required "charging" module changeout. It is true that Honda changed the minimum regenerative braking speed.

This is not a safety issue for regenerative braking. Indeed, my electric motorcycle has regenerative braking down to 0 MPH.

Honda corporate said the 19 MPH minimum regenerative braking speed reduced MPG in mountainous areas of the country. The local dealer complained that my driving range had no mountains. They requested a wavier for my car. Honda said "no." They made the change for ALL cars with replaced IMA batteries in America.

The good news is that the replacement IMA battery is NOT under warranty. The replacement battery costs $ 3500 US, but Honda replaced it for free when it castrophically failed. The local dealership said that I would not void any battery warranty if I wanted to "open her up."

I am an Extra Class amateur radio operator and am comfortable with working in the IMA compartment. What I need is an original IMA charging module or schematic. Any wrecked Insights out there? Honda required the original IMA charging module be returned in order to qualify for the free battery replacement.

I tried to keep the two IMA modules that were changed out. Honda gave me the new IMA battery (without warranty) in exchange for the two original modules and IMA battery.

Does anyone out there have additional information or schematic for the "improved" IMA battery charging module?

Thanks,

Ali Fant, WB5WAF

 

[Insightful Trekker]

Not sure what your asking for. The BCM (Battery Condition Module, IMA Battery "computer", :?: ) You can probably find one used from a salvage, search the internet. But as far as a schematic its not available, nor is it a simple circuit and much of its logic is _programmed_ into some type of controller.

What would solve all your problems is MIMA (Manual IMA) control

See this thread:

http://www.insightcentral.net/forum/vie ... php?t=3554

HTH!

 

[devin1955]

I have also noticed somewhat lower mileage since my battery and MCM/BCM were replaced. I did not notice the difference in speed where the regenerative braking cut off, but what I have ABSOLUTELY noticed is that the IMA system seems far more willing to provide assist where before it wouldn't. Even very moderate acceleration will produce assist of at least 50%, where before I would have to accelerate harder for it to even assist at all. I sometimes drive on mountain roads, and I fully expect that when I do, now I'll have a dead battery very quickly.

 

[Rick]

See, I'm not crazy. The addeage that you should drive for no IMA for maximum life cannot be done by any of us with the newer components. I've found an interesting sweet spot where it seems to throw more assist in to it and then if you back off the pedal enough to let the assist go away you can then ease back in to it with no assist. I used this a lot when driving with the AC on to try and keep it on the engine as to not enter force charge.

 

[flunkysama]

I had my battery, bcm and mcm replaced under warantee and since then my average MPG has increased. In normal driving the SOC stays near full, just like before the change.

The low MPH limit on regen is based on engine RPM, not MPH (at least for MT). In 3rd gear I have regen down to 19MPH, which is where autostop will kick in.

BTW. you do not need to keep the SOC at full all the time. It should fluctuate. If is drops too low, the system becomes more aggressive about charging and more stingy with assist. When SOC is high the system uses more assist more freely and less powerful regen.