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Yeah an android head unit would be far less of a hassle than a "normal" head unit. Have you checked the power draw of the head unit at idle just to be sure it's not draining the battery?
No though I could do so. The IMA supplies the car when the auto-stop comes in and also at idle. Voltages vary between 14V and about 12.8V depending I think on the actual charge of the 12V battery. I agree with a previous post auto-stop can be a little odd at times, working sometimes, others not.
 

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No though I could do so. The IMA supplies the car when the auto-stop comes in and also at idle. Voltages vary between 14V and about 12.8V depending I think on the actual charge of the 12V battery. I agree with a previous post auto-stop can be a little odd at times, working sometimes, others not.
My bad, I meant to say when the radio is sleeping, so with the car off. If it draws too much current it can make the battery go flat.
 

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To answer the Original posters question: YES the IMA factors into the starting process and under most condition the car starts using the IMA battery but process is kicked off by the under hood battery so we can use a much more dead under hood battery than other cars but the margin between able to start and not able to start is a very small one.

The cool thing is under very low temperatures the car uses the back up starter to start rather than the IMA but for that to work you need a working under hood battery and charge in the IMA(Not sure on that).
 

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No though I could do so. The IMA supplies the car when the auto-stop comes in and also at idle. Voltages vary between 14V and about 12.8V depending I think on the actual charge of the 12V battery. I agree with a previous post auto-stop can be a little odd at times, working sometimes, others not.
In my case, the voltage stays at 13.7V whenever car is turned on, doesn't matter if it's actually running or it's in auto-stop mode. If you could somehow "force" the auto-stop feature when the car is off then you could start it using ima motor at any time ...but if you only energize the 12V circuit without forcing car into thinking it's in auto stop and it's cold outside so the car would want to start using the backup starter motor then you can fry the DC-DC converter as it can supply only around 60 Amps of current and that's probably not enough to start the car using starter motor. That's why I think the IMA is not supplying power to the 12V circuit before you start the car.
 

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On my scan Gauge II I have seen the voltage vary from 11.7 to almost 14 volts under varying conditions during a trip. It reads off the OBD II port. Sitting parked in accessory it of course drops the longer I do that so i do not do it for long.

Car always uses the under hood and IMA battery for starting but I have never heard the back up starter. I trust the engineers designed all of that to be as reliable as possible and I like I can just jump in the car turn the key and drive it and not have to think about any of it.

Even a Prius has a 12 volt starting battery.
Article about why Hybrids have 12 Volt batteries. Connecting With Hybrids: Hybrid 12-Volt Battery Systems

In my case, the voltage stays at 13.7V whenever car is turned on, doesn't matter if it's actually running or it's in auto-stop mode. If you could somehow "force" the auto-stop feature when the car is off then you could start it using ima motor at any time ...but if you only energize the 12V circuit without forcing car into thinking it's in auto stop and it's cold outside so the car would want to start using the backup starter motor then you can fry the DC-DC converter as it can supply only around 60 Amps of current and that's probably not enough to start the car using starter motor. That's why I think the IMA is not supplying power to the 12V circuit before you start the car.
 

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Car always uses the under hood and IMA battery for starting but I have never heard the back up starter. I
I just swapped out a blown motor after the car had sat for months. The IMA battery indicator was empty at initial startup and the 12v starter was used (sounded like a typical Honda starting). After the (new used) engine began running, I forced charged the IMA up to 3 bars. After that, the IMA now spins up the engine on each start and I no longer hear the 12v starter at all.

FWIW
 

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How did you blow up the motor?

I just swapped out a blown motor after the car had sat for months. The IMA battery indicator was empty at initial startup and the 12v starter was used (sounded like a typical Honda starting). After the (new used) engine began running, I forced charged the IMA up to 3 bars. After that, the IMA now spins up the engine on each start and I no longer hear the 12v starter at all.

FWIW
 

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In my case, the voltage stays at 13.7V whenever car is turned on, doesn't matter if it's actually running or it's in auto-stop mode. If you could somehow "force" the auto-stop feature when the car is off then you could start it using ima motor at any time ...but if you only energize the 12V circuit without forcing car into thinking it's in auto stop and it's cold outside so the car would want to start using the backup starter motor then you can fry the DC-DC converter as it can supply only around 60 Amps of current and that's probably not enough to start the car using starter motor. That's why I think the IMA is not supplying power to the 12V circuit before you start the car.
Totally agrees with what I've seen. the IMA system only seems to provide power through the DC-DC converter with the car on, even with auto-stop engaged. I've read that inserting the key will charge the 12v battery using the IMA battery, but I've never gotten it to work as I can not detect any measurable voltage difference at the battery (car batteries need at least 13.2v to even BEGIN charging)

On my scan Gauge II I have seen the voltage vary from 11.7 to almost 14 volts under varying conditions during a trip. It reads off the OBD II port.
I still think you should have this ckecked, as it is not normal. anything under 12.8 is basically straight battery voltage and anything below 12.6 will drain the battery. I've done many tests, including city driving, highway driving and even going through a drive thru in all 3 driving modes and the voltage never dipped below 13.9.
My 2005 Civic had this behavior and it would kill a brand new battery in less than 2 years.

It was due to driving thru high water (hydro-locked).
Damn, that's rough. Are you planning to engine swap or something? Or can the engine be saved?
 

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It has been this way since car was bought brand new and through 1 under hood battery replacement. When car is in accessory I have seen as low as 11.5 and driving the car with auto stop etc I have seen variation. as I said. These are actual data points using the Scan Gauge II as I said. I believe it is working as designed and the Scan Gauge II through the OBD II port is just able to more accurately measure the battery voltage. The same scan gauge showed a steady voltage on my Alternator equipped previous car it was bought for till that car had an alternator issue. The same scan gauge showed the low voltage. The same scan gauge showed a low temperature issue on the previous car. I trust the device.

I have driven this car for now over 75000 miles and have seen the variations I mentioned. Maybe my particular car or the device are just different than the car and device you are using?

I may have inherited from my Dad an accessory socket voltmeter and can bang the two against each other but I will continue to trust the scan Gauge II over that very cheap Voltmeter.

In summary I don't think there is an issue and the Scan Gauge II is just more accurate.



I still think you should have this checked, as it is not normal. anything under 12.8 is basically straight battery voltage and anything below 12.6 will drain the battery. I've done many tests, including city driving, highway driving and even going through a drive thru in all 3 driving modes and the voltage never dipped below 13.9.
My 2005 Civic had this behavior and it would kill a brand new battery in less than 2 years.
 

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It has been this way since car was bought brand new and through 1 under hood battery replacement. When car is in accessory I have seen as low as 11.5 and driving the car with auto stop etc I have seen variation. as I said. These are actual data points using the Scan Gauge II as I said. I believe it is working as designed and the Scan Gauge II through the OBD II port is just able to more accurately measure the battery voltage. The same scan gauge showed a steady voltage on my Alternator equipped previous car it was bought for till that car had an alternator issue. The same scan gauge showed the low voltage. The same scan gauge showed a low temperature issue on the previous car. I trust the device.

I have driven this car for now over 75000 miles and have seen the variations I mentioned. Maybe my particular car or the device are just different than the car and device you are using?

I may have inherited from my Dad an accessory socket voltmeter and can bang the two against each other but I will continue to trust the scan Gauge II over that very cheap Voltmeter.

In summary I don't think there is an issue and the Scan Gauge II is just more accurate.
I was checking the voltage as detected by the ECU with OBD USB scanner and Torque pro android app. In theory the voltage can drop below the voltage of DC-DC converter if you are close to or exceed the converter's maximum current, which is I believe around 60 amp. Thb, I never noticed it dropping, even with headlights on and music playing with full volume, the voltage stayed at 13.7V. maybe if I turned more systems then it would drop, but I usually don't listen with full volume.
 
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