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I commented in another thread that keypass is back with android auto - although apparently not for everyone yet. Anyway, I was testing it out and tried the remote lock feature. The car was already locked but the headlights flashed. I immediately saw the charger light come on. I thought it would probably turn off quickly but instead, it kept drawing a small amount of power - roughly .15 to .20kw according to the charger display. I checked on it for the next twenty minutes and the car continued to draw this small amount of power. Torque Pro showed the power draw but nothing going to battery or cabin heating.

I checked again almost an hour and a half later. To my surprise, the battery heater was drawing about 2kw. Nothing for cabin heat. It was almost 54 degrees in the garage. As soon as the battery temp hit 60, the battery heater stopped but the power draw continued at a steady .14 kw. It's still pulling that small amount of power almost two hours after hitting the lock button in the app.

Any idea what might be going on here? Does pressing the remote lock trigger a conditioning mode without cabin heat? My only thought is that the low power draw is maybe for charging the 12 v battery although I haven't had any low readings there.
 

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Any idea what might be going on here? Does pressing the remote lock trigger a conditioning mode without cabin heat? My only thought is that the low power draw is maybe for charging the 12 v battery although I haven't had any low readings there.
You can see 12 volt battery charging on Torque Pro. The one for the OBD II port reads 12 volts or a bit more when the car is off. If the charger kicks in it can jump to 15 volts. I just took these to show you. After shutting down preconditioning, it is still charging the traction pack for a few minutes.

car asleep.jpg car preconditioning.jpg car back asleep.jpg
 

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The nutshell version: Remotely locking my already locked Bolt triggered a long running, low power draw which eventually turned into battery heating which eventually reverted back to a low draw (altogether lasting two hours in total...on a relatively warm day). I haven't seen that behavior reported. I've checked my 12v when the car is "off" and it usually hovers around 12.8 volts. Seems fine. Could the low draw be battery leveling of the pack cells?
 

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The nutshell version: Remotely locking my already locked Bolt triggered a long running, low power draw which eventually turned into battery heating which eventually reverted back to a low draw (altogether lasting two hours in total...on a relatively warm day). I haven't seen that behavior reported. I've checked my 12v when the car is "off" and it usually hovers around 12.8 volts. Seems fine. Could the low draw be battery leveling of the pack cells?
When our Bolt is plugged in, any disturbance...touching the door lock button, touching the J1772 plug release button, or opening the door can trigger slow charging of the traction pack for some minutes. The battery will pick up a percent or two charge. The car may also decide to run the battery conditioning, and charge the 12 volt battery.

[edit] This only happens when I have Torque Pro on, attempting to connect to the car. Using the fob to lock or unlock the car is also communicating. I assume this can happen when you use the Chevy app too.
 

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Discussion Starter #6
When our Bolt is plugged in, any disturbance...touching the door lock button, touching the J1772 plug release button, or opening the door can trigger slow charging of the traction pack for some minutes. The battery will pick up a percent or two charge. The car may also decide to run the battery conditioning, and charge the 12 volt battery.

[edit] This only happens when I have Torque Pro on, attempting to connect to the car. Using the fob to lock or unlock the car is also communicating. I assume this can happen when you use the Chevy app too.
Understood. My curiosity is really about what the car was doing with that two hour session on a relatively warm day. I don't have the full charge profile but given the temperature (and based on experience), the battery heating probably lasted less than twenty minutes of that two hours. The car was charged to it's target charge level already and the .15 to .2 kW draw that made up most of the session seems too low for that anyway.
 

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Understood. My curiosity is really about what the car was doing with that two hour session on a relatively warm day. I don't have the full charge profile but given the temperature (and based on experience), the battery heating probably lasted less than twenty minutes of that two hours. The car was charged to it's target charge level already and the .15 to .2 kW draw that made up most of the session seems too low for that anyway.
This is what I love about Torque Pro. You know where that power is going. You know the car is pulling power from the wall, but now you can pinpoint where it is going.
 

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This is what I love about Torque Pro. You know where that power is going. You know the car is pulling power from the wall, but now you can pinpoint where it is going.
That's the thing. I was looking at Torque Pro but couldn't figure it out. During the low power draw, there was nothing going to cabin heat, nothing going to battery heat. I could see the tiny draw on the "CAC Power" gauge. What does that mean, exactly? Now that I think of it, it's possible there may be some logs on the phone.
 

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That's the thing. I was looking at Torque Pro but couldn't figure it out. During the low power draw, there was nothing going to cabin heat, nothing going to battery heat. I could see the tiny draw on the "CAC Power" gauge. What does that mean, exactly? Now that I think of it, it's possible there may be some logs on the phone.

If you look at the Torque Pro screen shots I posted a few posts ago, I have the charging PIDs arranged in what I think of as logical arrangement. The AC charging column CAC is to the left. It shows the AC power coming into the car in kW. Below that are how that power is delivered in volts and amps. Power is just volts times amps, so this is more for curiosity. The DC charging column CDC has the same information for the DC coming out of the onboard charger going to the HPDM bus. If you are DC fast charging, the left CAC column is showing nothing, of course. Only the CDC column will be active.

If the CDC is active, and none of the car's other loads are showing any activity, watch the pack and average cell voltages climb, because the power must be going to the traction pack.
 

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When our Bolt is plugged in, any disturbance...touching the door lock button, touching the J1772 plug release button, or opening the door can trigger slow charging of the traction pack for some minutes.
That makes sense to me. If the car is plugged in and fully charged, it seems logical to me that you'd want it to stay fully charged - so anything that causes the car to "wake up" would turn on the AC-->DC converter in order to draw whatever power is needed from the wall rather than the battery. That probably necessitates bringing the battery online, and once that happens it probably goes through its end-of-charge balancing or whatever the heck it does. It's essentially the same thing as if you unplugged it and then plugged it right back in again.
 

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Discussion Starter #11
I had a saved log from around the time the battery heater shut off.

<shamelessplug>I loaded it into my Piddle Torque Pro graphing software</shamelessplug> and got the following. You'll see the green line go up right as battery heating stopped. That's "MG Voltage". What is that exactly? You'll see the red line (Charger HV Power) hover just above 0 after that. I don't have logs beyond this but whatever it was doing continued for some time.

29011
 

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It could be the cell balancing that you triggered. As it is known, ONLY when the battery is charging, the battery heater is engaging. Yes, there is that situation when the battery temp is too low so, if plugged in, the battery heater engages even if there is no charging active, but this time it wasn't the case, being that your garage was 54F. IMHO you saw the cell balancing process.
 

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That's "MG Voltage". What is that exactly?
That is traction pack voltage....basically, the average cell voltage x 96. If that yellow line is average cell voltage, I don't understand how it is not changing. Wait. The whole graph is only six minutes. It must be cell balancing. But I don't understand why you are seeing pack voltage only show up in the last minute, and climbing from nothing to full in a minute.
 

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Discussion Starter #14
The car was charged earlier that day to a 75% target charge level. That's why average cell voltage shows as somewhere between 3.8 and 3.9 volts while not charging. Maybe I'm reading your comment wrong but the legend for the green line on that chart is on the left side of the graph - meaning it peaked just below 4.2 volts. Here's a zoomed in version of just the MG Voltage at the point it kicks in until the log ends.

29014
 

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Discussion Starter #15
Tonight I opened the garage and noticed the car was drawing a very small amount of power. It hadn't been driven in 24 hours and the temp was nearly 60. I turned on Torque Pro and logged until some time after the charger turned off. It looks it was still doing something even after the charger stopped (when the red line drops to 0). HV Current (the blue line) actually kicks in at zero and drops to -0.150...drawing from the pack? Gotta assume this is battery conditioning...I guess. The car was at it's target charge level of 75%.
29050
 
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