06 Civic Hybrid Owners Manual tid-bits

[Rick]

Some interesting things in the owners manual.

"The battery level gauge does not read the battery level directly. It calculates the level by continuously measuring the current flow, voltage, and temperature.

Since the level is not read directly, small sensing errors can, over time, cause the gauge to read higher than the actual battery level. The system will then perform a correction, and the battery level gauge reading will drop suddenly. When this happens, IMA assist and Auto Idle Stop are disabled until the IMA battery is sufficiently recharged by normal driving. This should take only a few minutes.

This correction of the battery level fauge is normal and does not indicate a problem. If the IMA battery develops a problem or becomes deteriorated, the IMA system indicator will come on. If this happens, have the vehicle checked by your dealer as soon as possible."



"Auto Idle Stop
To maximize fuel economy, your Civic-Hybrid has an Auto Idle Stop function. Under certain conditions, the engine will shut off when you come to a stop. Those conditions are: []

-Outside temperature is between 10-100 degrees F. []

The Auto Idle Stop function activates if you speed up to 8 mph over and brake to a stop. And it can activate twice even if you speed up to 8 mph or below and brake to a stop."



"If the Auto Idle Stop is active for an extended period, the charging system indicator may come on. If it happens, start the engine.

The charging system indicator may also come on if the Integrated Motor Assist (IMA) battery charge drops below a desired level and the engine starts to recharge the battery.

This indicator may blink after you start the vehicle in the morning when the temperature is below -20 F (-30 C). It will stop blinking when the IMA battery warms up."



A few other interesting things about the car. The 12 volt battery looks to be the same Furukawa battery as the CVT Insight. The way the hold down is it looks as if you'd have to have that battery so an OEM replacement for the Insight may be available now.

The car also has an electric water pump so you have heat even with the engine off! Add this to the fact that you have the electric AC compressor the whole climate control can operate almost independently of the engine.

[Jackmpg]

Originally Posted by Rick

"The battery level gauge does not read the battery level directly. It calculates the level by continuously measuring the current flow, voltage, and temperature.

Since the level is not read directly, small sensing errors can, over time, cause the gauge to read higher than the actual battery level. The system will then perform a correction, and the battery level gauge reading will drop suddenly. When this happens, IMA assist and Auto Idle Stop are disabled until the IMA battery is sufficiently recharged by normal driving. This should take only a few minutes.

Huh, where have I heard this before, Jack

[Rick]

It reads almost word for word the same as the TSB honda issued to tell us recalibrations are normal.

[Will M]

I have a solar electric workshop. The meter I installed on it has a similar problem. While the meter claims to display volts, amps and amp-hours, only the volt measurement is "real". Everything else is calculated.

Apparently, you can't measure amps directly. You can easily measure volts, however, so, you set up a very low-level resistor and measure the miniscule voltage drop across the resistance.

That's the first level of abstraction. The second level is that the meter has to indirectly measure amperage in real time and remember how many amps have flowed in which direction over how much time. The third level of abstraction is that, knowing that the battery is less than perfectly efficient, you have to factor in the efficiency. Let's say you put 10 amps into the battery. You'll only get 8 amps out if it is 80% efficient.

Now, add that the third level of abstraction has additional variables. Lead-acid batteries are more efficient when they are discharged than when they are fully charged. Once fully charged, they heat up enough to make the acid boil. That heat is a loss of energy.

So, over time, any metering system like this is going to get less and less accurate. Eventually, it will become obvious that given the indicated amp-hours of electricity stored in the battery, it SHOULD have a voltage much higher or lower than it currently does. That's when you have to charge the battery until the voltage makes it obvious that it is fully charged, and then you re-set the indicated state of charge as fully charged.

Think of it like water. Imagine that you want to know how much water is in a storage tank. You can't measure what is actually in the tank, unless you pump it so full that water squirts out the top vent, or drain it so empty that there's nothing coming out the spigot.

These are extreme conditions you wish to avoid most of the time. Also imagine that you can't measure water volume as it flows into and out of a tank. You can measure how fast the water is travelling as it flows through the pipe (and you have a pretty good, rough idea of the diameter of the pipe). So, you measure the flow back and forth through this pipe and keep track of how much the net flow has been into and out of the tank.

Also, imagine that the water tank leaks and you know it. You factor that in as the "efficiency" of the tank.

Every now and then, you tap on the tank to hear whether it sounds full or empty. If your calculations say it should be mostly full and it sounds empty, or if your calculations say it should be empty and it sounds full, then you throw away your calculations and start pumping water into the tank until you see water gushing through the vent at the top. You then restart your calculations assuming that the tank is full.

That's what metering a battery is like. It's not just the Insight. It's any kind of metering when it comes to measuring how much energy you have in the system. Voltage is easy to measure, but it is also a really bad indicator of the actual storage in the battery because it varies so much depending on load conditions and the "recent history" of charge or discharge.

I hope this helps.