Strange charge light behavior

[adric22]

I just walked into my garage and noticed one of the charge indicator lights on the dash was flashing. The weird thing is, the car was not plugged in. It wasn't the center light either (such as for a charge timer) it was the far right light (right if you are standing in front of the car looking at it) and it was just flashing steadily as if the car was charging. I powered the car on and everything seemed normal. The battery had a full charge on it. It hasn't been driven since yesterday. When I turned it back off, the light didn't come back on. Anyone seen anything like that?

 

[LeftieBiker]

It does that when charging the 12 volt battery while off, when the battery heater is on, and I think, when it's sending data to Nissan while the car is off.

 

[MikeD]

adric22: I think in any case it means the DC to DC converter is on (most of the time it is off in "Off" mode). I think you could check this by placing a voltmeter across the battery terminals and verifying that there is ~13.1 v or more -- less than that (like normal at rest battery voltage) would mean the converter is off.

 

[TimLee]

Yes, it does that under various normal situations.
But make sure you check the resting 12V battery voltage.
The LEAF also will start charging the 12V if it is in ON mode (single button push) but it does not do that until the 12V battery drops to a dreadfully discharged point of 10.5 volts.

Some people have experienced double tap when shutting the LEAF off and inadvertently left it ON.
You probably didn't do that, but need to be sure.
Just because LEAF started does not mean 12V was fully charged.
Check the 12V battery voltage.

 

[MikeD]

TimLee: You wrote "The LEAF also will start charging the 12V if it is in ON mode (single button push) but it does not do that until the 12V battery drops to a dreadfully discharged point of 10.5 volts.". Could you please elaborate a bit more? In particular, which model year Leafs are you referring to (if not all), and where is the 10.5 v threshold documented?

edit update:
I have found it reassuring to have a 12v battery monitor (http://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0" onclick="window.open(this.href);return false inserted continuously in the power receptacle, since I often listen to the radio in "Acc" mode (BTW I think this is the mode you meant to refer to?). When I see it has dropped to around 12.00v or so, I change to "Ready" mode and charge until the volts monitor drops from the initial ~14.4v to its secondary ~13.1v charging level, when I revert to "Acc" mode again.

 

[TimLee]

Could you please elaborate a bit more? In particular, which model year Leafs are you referring to (if not all), and where is the 10.5 v threshold documented?

I have a fairly early 2011, no cold weather package.
I read the 10.5 from LEAF Spy.
I had the car charging to 100%.
Put foot on the brake and pushed Start button once which is what I normally do if waiting in the car while doing DCQC or L2.
Once the charging stopped, I came back to the car and discovered the vehicle is actually in On mode.
Once 12V battery voltage dropped to 10.5 V it activated the DC to DC and started charging the 12V.

This is one of the more stupid things in the LEAF programming.
Using the LEAF in On mode listening to radio is how my first 12V battery ended up replaced at no cost under warranty at two years.
What idiot engineer would think letting 12V sag to 10.5V is reasonable?
Only mostly charging at 13V is extremely marginal in my opinion.
But 10.5V?
Do you not care how many 12V batteries you destroy prematurely?

 

[aarond12]

I saw this yesterday when my 2-year-old daughter was playing in my car. I wondered what button she pushed...

 

[LeftieBiker]

edit update:
I have found it reassuring to have a 12v battery monitor (http://www.amazon.com/INNOVA-3721-Batte" onclick="window.open(this.href);return false; ... B000EVWDU0) inserted continuously in the power receptacle, since I often listen to the radio in "Acc" mode (BTW I think this is the mode you meant to refer to?). When I see it has dropped to around 12.00v or so, I change to "Ready" mode and charge until the volts monitor drops from the initial ~14.4v to its secondary ~13.1v charging level, when I revert to "Acc" mode again.

12.0 volts is far too low, and indicates a nearly-dead battery. Use "On" or "Ready" modes to listen to the radio.

 

[TimLee]

I have found it reassuring to have a 12v battery monitor (http://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0" onclick="window.open(this.href);return false inserted continuously in the power receptacle, since I often listen to the radio in "Acc" mode (BTW I think this is the mode you meant to refer to?). When I see it has dropped to around 12.00v or so, I change to "Ready" mode and charge until the volts monitor drops from the initial ~14.4v to its secondary ~13.1v charging level, when I revert to "Acc" mode again.

No.
I meant ON mode.
Use of either Accessory or ON mode in the LEAF is unwise unless the vehicle is charging.
The only mode in the LEAF that makes any effort to keep the 12V battery charged somewhat adequately is Ready mode.
And that is extremely marginal.
Under ideal conditions it might keep the 12V battery charged to around 60%.

Having a 12V battery monitor is a good idea.
But if you switch out of Ready mode when the LEAF decides to drop back to 13 or 13.1V you are badly discharging the 12V battery.
Likely down to less than 45% to 50% charge level.

 

[MikeD]

LeftieBiker & TimLee: Well, looks like we will just have to be in disagreement!

My 2011 original battery lasted over 3 years (and almost 30,000 miles) and I listened the hell out of my XM radio in "Acc" mode (why would Nissan allow me to use it then, it must be coincidence that mode is the least power hungry, and unlike "On" mode turns itself off after ~60 minutes (in case I fall asleep?) to prevent heavy discharge), and I only changed it out because the dealership said I ought to at the car's 3rd year checkup. Since I had the battery monitor, the resting voltage still seemed not low enough to replace (which I normally would have done myself).

Three years seems fine to me for a Leaf battery to last, even though it is slightly less than I am used to. Just as the Ecopia tires don't last as long as I would like (I realize that a heavier, longer lasting tire likely means lower efficiency), I am willing to replace my 12v battery more often if it means I get higher range.

Sorry, you guys -- I just don't find your authoritarian and simplistic pronouncements very persuasive! I need more evidence -- so please indulge me, if you will.

 

[MikeD]

aarond12: Could be just coincidence? I need to read up in the 2015 "Owner's Manual" to see what all has changed since 2011 model...

 

[jpadc]

I think the real issue is how much time the car spends in Ready mode. I drive under 2 miles to work, but usually add miles driving kids to school/practices/lessons - you know Dad stuff. Still, I need to watch my 12 volt battery level carefully. If you commute a lot of miles per day, likely your car spends enough time is Ready mode that the charge is adequate. The rest of us need to do things to help protect the 12 volt battery. I try to leave my car in Ready mode all the time when I'm going to stores etc and I just turn off the Heat/AC. I'm sure I could run down the 12 volt and get a warranty replacement, but that might leave me stranded sometime and I would like to avoid that.

 

[MikeD]

jpadc:
1) We have probably all had annoying past experiences with a battery that failed or at least struggled to start a ICE car, but realize the Leaf's 12v battery never has to output a lot of current (like to crank an engine) which suddenly reduces its voltage and thereby prevents proper Leaf functioning. So although the Leaf's battery can fail (i.e. voltage drops too low to start car electronics) for other reasons (like from a suddenly shorted cell), it is not subject to the starting failures we are most familiar with.
2) The Leaf charges its 12v battery at a higher voltage (and for a longer time) when it considers it necessary (presumably inadequate voltage) -- and this includes when you are charging its main battery pack.
3) If you find it reassuring to monitor the 12v battery (as I do), get the convenient-to-use voltage monitor (link provided earlier) plugged into the power outlet that you can look at regularly. You can easily verify its resting voltage when starting by cycling thru "Acc" mode before "Ready" mode.
4) Another possible approach is to replace the battery on a scheduled basis (like every 3 years) if really concerned about sudden battery failure (like from a shorted cell or other age related problem).