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Discussion Starter · #1 ·
New to this board so forgive my asking a Q that I am sure has been asked before.
I am driving my 05 with the AC on and the battery bars are up to about 2 from the top, but if I stop to go into a store or something when i return the bars are in the bottom two red bars. Is this a problem?
 

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Don't worry about it. The car manages the battery state of charge quite nicely. My suggestion is to keep the MFD on the consumption screen. I haven't looked at the Energy screen in months. It's eye candy.
 

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The hybrid battery is not that big, and much of its full capacity is not used to preserve its life. So on a nominal charge (about 60%, or 6 bars), you can go up to 3 miles tops. 1-1/2 to 2 miles is probably closer to what you'll get.

When actually driving, the system will try to keep the state of charge (SOC) about 6 bars. If stationary (idling), it will allow the SOC to go down to 2 bars before resorting to running the ICE to maintain that charge. The car can't predict the future, but it is more efficient to charge the battery while you are driving and using the ICE at higher RPMs than to run the ICE at near idle speed to charge the battery. So it waits in hope that you will soon be driving before it has to charge.
 

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I don't understand this. Skip didn't say that while he was in the store the car was left on with the A/C running, although it is a reasonable inference.

Skip, is this what's going on?

1. You're driving; the car's battery is fully charged (within two bars of the top, anyway); you pull up to the store and turn the car off. Engine is off. Air Conditioning is off. Then you come out of the store and restart the car. NOW the battery condition shows only two red bars at the bottom.

Or

2. You pull up to the store; the ICE is not running but the A/C is; someone stays in the car so that it is left on; the A/C has been running only on the battery and the car has not started the ICE. You come out of the store and observe that NOW the battery condition shows only two red bars at the bottom.
 

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OK, point taken.
Temperature has a factor with reported SOC. It's like humidity. Cold air holds less, so the air feels more humid in the evenings than during the middle of the day when it's warmer. The absolute amount of water vapor in the air hasn't changed, but the difference between what the air can hold to what it is holding has. Same with the battery. Same number of electrons stored, but when the battery is warm, it can hold more so the % SOC is lower.

Although 6 bars to 2 seems quite a bit even for the biggest of temperature shifts.

When the car is powered off though, the system main relays completely disconnect the battery, save the voltage sensor connections to the battery ECU to determine SOC by voltage, and that the modules are about even.
 

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Discussion Starter · #8 ·
jamesfchumbley said:
I don't understand this. Skip didn't say that while he was in the store the car was left on with the A/C running, although it is a reasonable inference.

Skip, is this what's going on?

1. You're driving; the car's battery is fully charged (within two bars of the top, anyway); you pull up to the store and turn the car off. Engine is off. Air Conditioning is off. Then you come out of the store and restart the car. NOW the battery condition shows only two red bars at the bottom.

Or

2. You pull up to the store; the ICE is not running but the A/C is; someone stays in the car so that it is left on; the A/C has been running only on the battery and the car has not started the ICE. You come out of the store and observe that NOW the battery condition shows only two red bars at the bottom.
Number 1 I left the car with its engine stopped and locked it up and went into the store. Got back in and it was discharged to 2 bars (red)
 

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By 'engine stopped' do you mean the car was OFF, or you left it still in READY? The hybrid battery is totally disconnected from the rest of the system when not in READY. If the car is locked but left in READY, the battery can discharge down to 2 bars, after which ICE will start long enough to maintain that level.
Though it can be challenging, especially with SKS, you can lock the car while still in READY. Usually that means using the mechanical key.
 
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