Gas motor out of the blue

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Geor99

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I was just eating lunch with the car turned on and in park.

AFTER about 20 minutes the ICE rumbled to life for 3-5 minutes. The screen showed it sending green to the battery (charge.) I have 32 miles of charge on the battery.

The ice ran yesterday on the freeway for at least 15 miles, so it did'nt start today due to a long period of no use.

Any clue what's happening here? It's no big deal. Temp is 72F, fyi.
 
It was probably after-effects of the lunar eclipse. I've heard lining up large celestial bodies can affect magnetic fields and cause electronics to hiccup. Point your car directly at the moon tonight and all will be well in the morning.
 
Alright, alright, I get your point. It's not a big deal to burn 10 cents worth of fuel. I'm an engineer and things like this interest me.
 
Hey, I'm right there with you. It seems strange for the engine to start and it would be nice to be able to know why. The 10 cents worth of fuel helps in in the pain of not being able to decipher, but doesn't keep one from wanting to know...
 
Happen to mine as well since last week ICE running on/off although 100% charged (EV range 40+ mile) and start a day as cruised downhill. Few cents of gas wasn't a problem, but why? not suppose likes that for PHEV after full of charge.
-capt3450
 
Geor99 said:
Alright, alright, I get your point. It's not a big deal to burn 10 cents worth of fuel. I'm an engineer and things like this interest me.
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My understanding is ICE will come to life if the traction battery cannot meet the demands of the user(which output is governed by the chemistry temp).
Before you start the car next time, and it's freaking cold out(~10f), make sure the climate control is off. You'll notice the blue EV bar has been truncated due to temp.. While driving the car with the climate off, you might also notice that bar will grow as the battery chem warms up..
It seems like the traction battery runs a budget equation, heavily influenced by the operating temp. Since running climate heat consumes so much energy, the deficit forces the car to compensate by running the generator.

I'm guessing this is why the engine will ignore the warmup routine under this scenario, and go straight to free-revving, for the sake of load balancing.
 
capt3450 said:
Happen to mine as well since last week ICE running on/off although 100% charged (EV range 40+ mile) and start a day as cruised downhill. Few cents of gas wasn't a problem, but why? not suppose likes that for PHEV after full of charge.
-capt3450
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I know this one. The ice motor starts when you are obercharged- like going downhill on a full battery. It disappates the excess energy through fighting the output of the ice.

That's how I understand that situation. My situation is still a mystery to me;)
 
Geor99 said:
I know this one. The ice motor starts when you are obercharged- like going downhill on a full battery. It disappates the excess energy through fighting the output of the ice.

That's how I understand that situation. My situation is still a mystery to me;)
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It's a different situation as I only had 30 miles of charge left and it was 70F outside. I was nowhere near a full charge.
 
On another thread a user posted below. Could the ice be charging my 12v battery as I was just sitting there listening to the radio for 20 minutes? --

As perhaps an aside, does anyone know if the Accessory mode on Clarity is confined to the 12v battery or if it uses the larger battery?
i.e. I remember with older cars having to be careful not to kill the 12v. In my family as likely others, this sort of became a rule to not use radio or anything that draws power when parked (to avoid any related problems).
 
Geor99 said:
On another thread a user posted below. Could the ice be charging my 12v battery as I was just sitting there listening to the radio for 20 minutes? --

As perhaps an aside, does anyone know if the Accessory mode on Clarity is confined to the 12v battery or if it uses the larger battery?
i.e. I remember with older cars having to be careful not to kill the 12v. In my family as likely others, this sort of became a rule to not use radio or anything that draws power when parked (to avoid any related problems).
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Radios draw milliamps. Unless you leave it on for weeks while the car is off, a radio is never going to be what kills a battery.
 
Geor99 said:
Alright, alright, I get your point. It's not a big deal to burn 10 cents worth of fuel. I'm an engineer and things like this interest me.
Click to expand...
I'm actually interested too! I've given up on figuring out the algorithm the car uses to run the ICE, so I've had to hide behind some humor to save my sanity. My wife thinks it's the hamsters in the engine compartment that need to exercise on their wheel when our ICE runs. o_O
 
petteyg359 said:
Radios draw milliamps. Unless you leave it on for weeks while the car is off, a radio is never going to be what kills a battery.
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What you say may be true, but I remember with my 2012 Plugin Prius, I remember sitting in the cell phone lot with the car in accessory mode waiting to pick someone up at the airport and listening to podcasts on bluetooth, after a relatively short time (10 minutes??) I would get a warning message and the accessory mode would turn itself off. If I wanted to continue to listen, I would have to turn the whole shebang on.
 
On an older car, probably with a dying battery, I one time had the key turned forward as far as possible without actually starting the motor; and 20-30 minutes later; it needed a jump.

The battery worked fine afterwards for a few months.

On thus car, as most, you could turn the key backwards for the radio, or halfway forward for lights and other things.

I blew the battery charge going forward that time. So perhaps, it uses more than just the radio milliamps. And perhaps my Clarity did crank up the ice to give the 12v battery a charge?

I'm just guessing:) Once again, this is all academic as it doesn't really matter at all in the big picture.
 
petteyg359 said:
Radios draw milliamps. Unless you leave it on for weeks while the car is off, a radio is never going to be what kills a battery.
Click to expand...
Years ago, when radios were single DIN units with no screens and small amps driving a couple speakers, this may have been the case. It is definitely not now. A typical head unit, with touch screen interface and an amp driving several speakers, requires up to 10 amps. Pioneer recommends operating their touch screen head units only with the engine running to avoid depleting the vehicle’s battery. I don’t know what brand head unit is in the Clarity, but I’m certain it uses at least a few watts even listening quietly to the radio, which is far more than milliamps. It would take more information to know exactly how long a particular starting battery would run a particular radio, but depleting a starting battery by leaving a vehicle in accessory mode to use the head unit could be a risk. The question is whether that’s a concern in the Clarity and could explain the ICE starting.
 
I have the following observations. I agree that it has to do with the 12V battery. The other night in Toronto around -20C. I drove to dinner and parking outside for around 90 minutes. On the way back the car battery still have 35km left (around 65% on EV) I noticed the ICE came on even though there are enough battery left. It happened at the moment when I turned on the front windshield air defrost. Upon further testing, it is related to the internal fan blower. When the fan blower is set to 4 bars or more the ICE would turn on, reducing it to 3 bars, the ICE turns off. Interesting that by turning on/off the seat heater, rear/mirror defrost, it had no effect on turning on the ICE. I suspect the fan motor is drawing off too much from the 12V battery and the ICE turns on to charge it. When the outside temperature warms up like yesterday, ICE did not turned on even when the fan is at MAX.

Other interesting observation is that the battery warmer draws about 2A from the 240V kicking in for around 15-20 min every few hours when the car is plugged into the charger. This happens at very cold temperature. Also the charging rate for the main battery is reduce to 20A from 30A when the temperature is very cold. I found these readings when checking my charger logs.
 
Your observation confirms what @LegoZ wrote in the Clarity Issues thread: The ICE will start up in response to the climate-control system. However, because there is no alternator, the ICE never directly charges the 12v battery. The ICE can charge the high-voltage battery though the starter motor/generator and then the high-voltage battery charges the 12v battery through the DC-to-DC converter.

However, @JimW in the "Honda dishonest about EV Range (in cold climates)" thread doesn't believe the climate-control system will cause the ICE to start unless the high-voltage battery is nearly depleted.
 
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I'm confused. I was thinking that the behavior was solved- until the last post:)

So, the ice doesn't charge the 12v because there is no alternator? If I never charge the car, the 12v battery is doomed to go dead?

Especially on a long freeway trip with no regenerative breaking- the 12v would die every time, no?
 
The Clarity starts its ICE to generate power when the charge in the high-voltage battery gets too low. So it makes sure there is always power available to send through the DC-to-DC converter to the 12v battery.

So don't worry about being on a long freeway trip with no regenerative braking, because when your EV range runs out the Clarity will use its ICE to make sure the charge in the high-voltage battery never goes below two bars.
 
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From my post, there was sufficient HV battery left (36km) and yet the ICE turns on when I turn the fan on beyond 4 bars. I think there is a temperature dependency as it didn't happen before/or after. Only that night when the outside temperature is at -20C. It makes sense the car want help to power the inverter as it doesn't want to drain the HV battery faster than it needs to.
 
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