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Is there any way that a layman (not a Honda dealership, but me) can test the efficiency of a battery of recharge system in an insight?

Is it maybe possible to completely discharge a battery and time it's recharge time, for example?

If not - What are the key signs that there may be something wrong with the battery or recharge system?

Thanks

S;p
 

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Space Panda said:
What are the key signs that there may be something wrong with the battery or recharge system?
The red IMA warning light comes on while driving and there is a valid code.

Even Honda dealerships cannot "test" the IMA battery. There would be "reasonably" easy tests to do (with the right equipment) to measure the IMA batteries effective capacity. But such tools are expensive and not widely available. A narrowing or reduction of its rated capacity is a reality of all rechargable batteries as they age. But perhaps one of the more difficult factors to introduce is temperature. In warmer conditions our NiMH's will "suffer" more as they age. Other battery chemistries have somewhat different characteristics.

Generally an experienced Insighter could road test it for you and give a very rough "estimate" based on how robust or fragile the IMA SoC gauge appears in response to driving.

Your example is about as accurate as can be done "seat of the pants". However, its discharge time from "full" would probably be a better indication. Someone with an advanced understanding of electricity could "devise" a test, do the calculations involved, and explain the strengths and weaknesses of the test chosen. A "layman" cannot.

Sorry but that's the way this cookie crumbles. :p

HTH! :)
 

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The problem with Nmh batteries is that it is difficult to know if the battery is charged. The computer in the Insight estimates the charge based on time and current flow. To know the "capacity" of the battery you would have to slowly discharge it through a resistance, measure the voltage across the resistance, graph the results and calculate the power mathmatically. The problem with this aproach is not only the difficulty and painstaking nature of the experiment , but also the fact that it does not indicate the internal resistance of the pack. As a pack ages its internal resistance goes up. This can be caused by a loss of moisture or a deterioration of the cells chemistry or construction. It can also be limited to one cell or distributed amoungst the cells.

The Imperical approach is to charge the cells up using the guage as a guide, then accellerate at full throttle from zero to sixty a number of times, putting the engine in neutral while slowing down to prevent recharging the pack. This will quikly depleate even a healthy pack. The trouble is that we have no data base for what is normal. However, if you did this experiment and reported back to us we would have the first data to start a data base for others.

Lets say that one run is sufficient to discharge your pack. That would be sufficient to diagnose a toasted pack. Several runs would indicate a relatively healthy one.
 

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Hi Panda,

I'm going to assume you want to test the battery, not the recharge system. The recharge system (the BCU) is electronic and will likely fail in a digital way: it either works or it doesn't. When it doesn't, it will be obvious (IMA light on, no green bars on the charge display).

There is a relatively easy procedure to test the capacity of the battery, which is one of the parameters that change when it ages. It has been proposed years ago in the yahoo group, but I'll give a brief recap:

-Pull the fuse for the IMA (you need to look up here or in your manual which one). Plug it back in after a couple minutes. This resets the state-of-charge gauge to zero.
-Run the engine at idle at 3000rpm.
-Watch the SoC gauge climb very slowly slowly at first, then suddenly change to a fast pace to show one bar less than full.
-Drive a few feet to put the car into auto-idle stop.
-Turn on headlights, fan to max, rear defogger.
-Start stopwatch
-watch SoC gauge drop very slowly at first, then suddenly change to a fast pace to one bar. Note how many bars were left when this started and stop the stopwatch.

Given the constant load the time to empty is a good measure for usable capacity in your battery. The tricky bit is finding other Insights to compare to. The number of bars left on the gauge when it suddenly goes empty (a recalibration or recal), is also a good measure: if it's more than half, the battery is pretty well worn.

It would be great if we could motivate a bunch of people on this board to do the test and post results. But it's time- and gas-consuming.
 

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IIRC there is also an old post in here (or there) concerning the 02 BCM "update". It prohibited such an IMA discharge (key-on, engine-off) or maybe its in the one of the newest MCM/BCM version(s), I'm not totally clear on this.

But if not then that's a "test" I was referencing. Load / time = capacity. As all rechargable batteries age their capacity will shrink. But given the Insight's middle of range usage of capacity the next question would be how to correlate its "calculated" diminished capacity with some sort of remaining life expectancy.

HTH! :)
 

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Armin said:
Drive a few feet to put the car into auto-idle stop. -Turn on headlights, fan to max, rear defogger. -Start stopwatch -watch SoC gauge drop very slowly at first, then suddenly change to a fast pace to one bar. Note how many bars were left when this started and stop the stopwatch.
Maybe its me, but I see a flaw in this test. Wouldn't the condition of the 12v battery have some affect on the rate of discharge of the battery pack in the rear? (Since the 12v supply still comes from the 12v battery and the DC-DC converter recharges it from the 144v pack. An older 12v battery will affect the rate of discharge). Also, late model 02s and up look at the battery state of charge differently and I think that they do not have to perform recals as often (if any) as the previous controllers did.

Insightful Trekker said:
It prohibited such an IMA discharge (key-on, engine-off) or maybe its in the one of the newest MCM/BCM version(s), I'm not totally clear on this.
I have an 03 CVT an I was driving in a Walmart parking lot (leaving) when my cell phone rang. I pulled into a parking space just to talk and my car went into auto stop. While talking and with my foot on the brake for about 20 minutes, my SOC went from one bar from the top to 4 bars from the top. So I think that I'm answering part of John's post whereas on 03 CVT will still discharge the 144v pack while in autostop.

JoeCVT - Just your average CVT owner
 

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joecvt said:
Maybe its me, but I see a flaw in this test. Wouldn't the condition of the 12v battery have some affect on the rate of discharge of the battery pack in the rear?
Good point, Joe!

I think the effect is minor, though:
The load in this case is high enough to force the DC-DC converter on immediately, no matter how good your 12V battery. So the only affect the 12V battery might have is any self discharge current going through it. This will be negligible, unless your 12V battery is so bad that you have to jump-start your car every time.

There is a finer point to the end of this test, too: After the recal occurs (SoC drops to one bar), the DC-DC converter continues to provide power to the 12V system. That will go on until a while after the SoC went completely blank. When the DC-DC finally quits to prevent deep-discharge in the 144V battery, the little one will be on it's own powering the heavy load. Now you need to turn things off quickly to prevent it from going flat!
 
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