ICE comes on when car stopped, every day during driving

[Neil]

I've read numerous other posts about people who are wondering about why the ICE is coming on in different situations (going down a hill for example) but I thought I'd share my experience because I haven't seen anything about my specific case happening. Forgive me if I missed a previous thread in my search.

• The car is sometimes not using up the full battery charge for my regular commute of 48-55 miles, instead keeping the battery charged at higher levels and using gas
• Happens in Econ and Normal mode
• Car did not do this during first ~2 weeks
• ICE comes on every day before battery is drained. It occurs both when:
  
  
  • car is stopped (power flow shows that gas engine is charging battery as seen in picture) and
    
    
    
    
  • car is moving (power flow shows both gas and battery being used, accelerator is not being pushed hard and the solid blue arc is not there on the bottom)
    
    
  • It does use EV for at least the majority of the drive

I brought it into my dealership and asked about this and was told simply that the car cannot operate without gas and that the car decides when to use the ICE. I found it particularly strange that the engine would come on to recharge the battery when it is showing full capacity and the car is at a stop, but they could not explain this to me. Just said it was normal. Has anyone else had similar experiences?

 

[jdonalds]

Sounds wrong to me.

 

[insightman]

My Clarity went many months without using gas. Perhaps your dealer's service personnel are confusing the Clarity with Honda's non-plug-in hybrids, the Accord Hybrid and the Insight.

Perhaps your Clarity was built the same day as BobCubsFan's Clarity. You'll have to compare serial numbers with him.

 

[KentuckyKen]

That is atypical behavior (unless you parked next to Bob’s Clarity).
Seriously though, it sounds like its in some kind of state between HV and non-HV (“EV”). Did the delaer check to see if any diagnostic codes were recorded like faulty sensors messing up the algorithm?

Have you tried a reset by disconnecting the negative terminal of the 12v battery? That’s all I can think of. It’s definitely not acting like it’s supposed to.

 

[Kranberry]

I've read numerous other posts about people who are wondering about why the ICE is coming on in different situations (going down a hill for example) but I thought I'd share my experience because I haven't seen anything about my specific case happening. Forgive me if I missed a previous thread in my search.

• The car is sometimes not using up the full battery charge for my regular commute of 48-55 miles, instead keeping the battery charged at higher levels and using gas
• Happens in Econ and Normal mode
• Car did not do this during first ~2 weeks
• ICE comes on every day before battery is drained. It occurs both when:
  
  • car is stopped (power flow shows that gas engine is charging battery as seen in picture) and
    
    
    
    
  • car is moving (power flow shows both gas and battery being used, accelerator is not being pushed hard and the solid blue arc is not there on the bottom)
    
    
  • It does use EV for at least the majority of the drive

I brought it into my dealership and asked about this and was told simply that the car cannot operate without gas and that the car decides when to use the ICE. I found it particularly strange that the engine would come on to recharge the battery when it is showing full capacity and the car is at a stop, but they could not explain this to me. Just said it was normal. Has anyone else had similar experiences?

I've had this happen to me on a few occassions. Generally, this happens when I have a full charge, and then I push the car hard enough that the ICE comes on and then it switches to this mode. It happend about 2 times in the past few weeks. Also had it happen one time when I was in Sport mode, again pushed into the ICE and when I switched to ECON mode shortly after it stayed on ICE as you have above.

 

[kevosuki]

Happens to me randomly when my car is fully charged. The engine will randomly turn on when braking (doesn't matter the intensity of braking.) I've mitigated this by setting my charge timers to reach 80% charge so I get full braking regeneration and no chance of unexpected ICE operation on weekdays. It's annoying to set the charge timers every day and Honda should have rethought their way when designing the battery and motor. The Chevy Volt was able to be charged "100%" and have full regen and ICE would never come on unless there's "0%" charge, why can't the Clarity do it?

 

[Carro con enchufe]

According to your screen:

-you have a full battery charge
-you’ve driven a mile since your charge

Therefore, the ICE has come on with a known issue on this forum - you have a full battery and regen (including from braking) caused the engine to kick in.

If you didn’t have a full battery, I’d agree that this is strange. But since you have a full battery, it’s explainable and happens to many of us.

Plus the ICE will stay on for 5-10 minutes until it warms up. Which is why it’s on while stopped.

 

[Neil]

A few responses:
-The dealer replaced the voltage sensor because I am also having issues keeping it charging, but that didn't change anything
-Will look into 12v battery reconnect
-I agree this happens if you push the pedal down far enough, it will go into using ICE and stay there. However this is happening when I am not pushing peddle down past the ICE-start point
-It does seem to occur more frequently when battery is full or nearly full, however it will still sometimes switch to hybrid or charge mode when the battery is above 2 bars but less than full. I will keep watching to see how often it happens. Difficult to take a picture of it when not stopped though Sounds like this particular behavior happens is not consistent with other owners' experience

 

[AnthonyW]

Neil, see the post I just created that explains this behavior. The next time it comes on while driving try to take note of the exact circumstances and conditions when it comes on but the battery is less than full. Ambient temperature, speed, charge level, where you were at on the blue acceleration curve, sudden or hard breaking having just occurred. Anything you can remember about what was going on when it came on. I have never had the ICE come on when less then full and I didn’t want it to. If we know the conditions, other folks might be able to recreate it.


Sent from my iPhone using Inside EVs

 

[insightman]

Happens to me randomly when my car is fully charged. The engine will randomly turn on when braking (doesn't matter the intensity of braking.) I've mitigated this by setting my charge timers to reach 80% charge so I get full braking regeneration and no chance of unexpected ICE operation on weekdays. It's annoying to set the charge timers every day and Honda should have rethought their way when designing the battery and motor. The Chevy Volt was able to be charged "100%" and have full regen and ICE would never come on unless there's "0%" charge, why can't the Clarity do it?

I'd love to know what the Volt does with the electricity regenerated during braking when it can't send it to the fully charged battery. Do you feel the seats suddenly get warmer?

 

[ab13]

Happens to me randomly when my car is fully charged. The engine will randomly turn on when braking (doesn't matter the intensity of braking.) I've mitigated this by setting my charge timers to reach 80% charge so I get full braking regeneration and no chance of unexpected ICE operation on weekdays. It's annoying to set the charge timers every day and Honda should have rethought their way when designing the battery and motor. The Chevy Volt was able to be charged "100%" and have full regen and ICE would never come on unless there's "0%" charge, why can't the Clarity do it?

They designed it as a hybrid with a large battery, not a battery vehicle with a backup generator. The reason is most likely cost. When you make a product, you have to consider cost, size, weight, manufacturability, etc... In order to get this type of drivetrain into many other vehicles over the next several years, the cost needs to be kept down if not reduced. For example, the hybrid Accord uses the same system, but with only a small hybrid battery. The comparable vehicles like Camry or Malibu hybrid are about $3000 more. A Volt has a similar price to the Clarity, but it's smaller than a Prius in capacity, while the Clarity is larger than the Camry in capacity. These are the trade offs in regards to cost.

This kind of issue might be solved by allowing the user to set the charge percentage, such as 97% or whatever number they want. This could be done by software, but whether it will be provided is TBD.

 

[kevosuki]

I'd love to know what the Volt does with the electricity regenerated during braking when it can't send it to the fully charged battery. Do you feel the seats suddenly get warmer?

Nope. I believe they just have a bigger buffer (20%-80% is the operating range as I've read.). I imagine taking on miles of downhill on a full charge might cause Clarity like behavior but it's a bit disappointing that my mild hill sometimes triggers ICE. The interior is much nicer than the volt which is why I switched, but I prefer the volts drive train more.

 

[ab13]

Nope. I believe they just have a bigger buffer (20%-80% is the operating range as I've read.). I imagine taking on miles of downhill on a full charge might cause Clarity like behavior but it's a bit disappointing that my mild hill sometimes triggers ICE. The interior is much nicer than the volt which is why I switched, but I prefer the volts drive train more.

A bigger battery is more cost and less interior space. Lower cost was chosen over a bigger battery buffer. The Volt has an additional clutch to disengage the ICE, but that's more cost and space requirement. The other option is to go to friction brakes like a BEV would do. That is less desirable on the brakes.

 

[bfd]

Sometimes, just regenerative braking on level ground can cause this to happen. I haven't seen a satisfying explanation yet for why this happens, but I've read enough educated guesses to be somewhat satisfied that the ICE start up with full battery trying to accept further charge while the vehicle is being operated is probably normal behavior.

 

[AnthonyW]

In your picture which direction is the green energy flowing?

 

[insightman]

Nope. I believe they just have a bigger buffer (20%-80% is the operating range as I've read.). I imagine taking on miles of downhill on a full charge might cause Clarity like behavior but it's a bit disappointing that my mild hill sometimes triggers ICE. The interior is much nicer than the volt which is why I switched, but I prefer the volts drive train more.

So the Volt lugs around a bigger battery and leaves a big part of it as a giant uncharged buffer that doesn't normally contribute to range just to ensure regen braking is possible? What happens when the giant buffer gets full?

 

[Kranberry]

Okay so it happened 2 days in a row. On highway at low speeds, the backup is over and I accelerate not really hard, but hard enough that in Sport mode, my ICE turns on. No issues there, however, exit highway and ICE remains on (around 60% charge) and the EV mode disappears and the entire semicircle is white. No blue for EV. Even when I get to a stop, ICE is running pretty much non-stop charging my battery at a light and it is still white. If I hit Hybrid mode button, engine shuts off and a little blue comes back, turn it off, all white again. ICE doesn't immediately turn on but sure enough it will. So it isn't a 100% charge issue. I have in the past 2 months primarily using Econ mode, but tried Sport mode as I can now charge at work. But if ICE is going to turn on and stay on while using it, it is deterring me from wanting to use this mode. I understand if ICE turns on the engine may stay on a while before shutting off to protect the engine, but 30 minutes after it starts it is still going on.

 

[Carro con enchufe]

Okay so it happened 2 days in a row. On highway at low speeds, the backup is over and I accelerate not really hard, but hard enough that in Sport mode, my ICE turns on. No issues there, however, exit highway and ICE remains on (around 60% charge) and the EV mode disappears and the entire semicircle is white. No blue for EV. Even when I get to a stop, ICE is running pretty much non-stop charging my battery at a light and it is still white. If I hit Hybrid mode button, engine shuts off and a little blue comes back, turn it off, all white again. ICE doesn't immediately turn on but sure enough it will. So it isn't a 100% charge issue. I have in the past 2 months primarily using Econ mode, but tried Sport mode as I can now charge at work. But if ICE is going to turn on and stay on while using it, it is deterring me from wanting to use this mode. I understand if ICE turns on the engine may stay on a while before shutting off to protect the engine, but 30 minutes after it starts it is still going on.

The longest I’ve seen is 20 minutes, but usually it’s 5 or less. Let it do it’s thing and don’t obsess over it.

 

[ab13]

So the Volt lugs around a bigger battery and leaves a big part of it as a giant uncharged buffer that doesn't normally contribute to range just to ensure regen braking is possible? What happens when the giant buffer gets full?

The generator motor runs to burn the energy and create additional load.

Regardless, the purpose of the buffer is to protect the battery. Each person would have a different requirement if it was to accept regenerative charging on "full charge." They guy at the top of the hill needs more while the guy at the bottom needs almost none. That's why I say the charge level should be user selectable, that sets the "arbitrary" buffer level. If someone consistently gains say 1kw going downhill then it makes sense to charge 1kw less, otherwise that 1kw is thrown away.

I read that BEV owners in the mountains don't fully charge their vehicles commonly. That's why I point out that they chose to design it as a hybrid, knowing the ice could be used at times when necessary.

 

[Kranberry]

The longest I’ve seen is 20 minutes, but usually it’s 5 or less. Let it do it’s thing and don’t obsess over it.

Mine was a good 30+ minutes. Not really obsessing over it, but why would it behave as if it was in a mix of HV/HV Charge mode when HV is not turned on. However, if I go into Hybrid mode, I can accelerate slowly and stay in EV type usage (i.e. only battery). Yet in non HV mode the car acts more like HV Charge mode. I just find it odd, this never happened to me before when I was in Econ mode. In fact it happened again at lunch when I went out and used Sport mode again. Although I shortly parked after it turned on (within 2 mins).