Leaf is dead after vacation...

[RegGuheert]

For reference, here is a chart from 2011 LEAF Owner's Manual Revised showing what features are available in each mode:

Power switch position                       LOCK/OFF         ACC          ON         READY to drive
--------------------------------------------------------------------------------------------------
Fan                                            -              -        Available       Available
Heater and air conditioner                     -              -        Available*1     Available
A/C-Heater Timer (Climate Ctrl. Timer)     Available*2        -            -               -
Remote control                             Available          -            -               -
*1: Can only be used during charging.
*2: The charger must be connected.

 

[TonyWilliams]

As I posted many times, if the battery is below about 20%, the heater will not work in any mode while charging.

 

[RegGuheert]

As I posted many times, if the battery is below about 20%, the heater will not work in any mode while charging.

Thanks! That's probably a good thing! I wonder if they will change this for 2013, assuming the heat pump is a standard feature.

I took a little data on the 12-V battery in our LEAF. It's not overly scientific since I did not disconnect the battery from the car nor measure the load current on it and that is almost certainly not zero, but perhaps something can be gleaned from this information:

- Battery voltage with car plugged in having sat for ~30 hours after being driven last: 12.45 V.
- Battery voltage with car plugged in 30 minutes after an L2 charge from 3 bars to 10 bars: 12.62 V.

Since I do not know the tare current for the car in these conditions I cannot really say that these are resting voltages for the battery. Since the current may be 10s of mAs, this is probably lower than the resting voltage. I *suspect* SOC is close to 100% in the second measurement, but that is not definite. If I assume battery was fully charged both after the drive and after the charge and that the current in the two measurements above was the same, it appears that the battery might be losing about 13% of its charge each day, which is consistent with a dead battery after nine days.

Anyway, I may make some more measurements of this type over time as well as some tare measurements on the car to try to determine how quickly the battery drains. I would like to use the LEAF as my airport car, but because of the distance I *must* charge at the airport to get home, so I can't simply leave it unconnected as others here do.

BTW, does anyone know the Ah capacity of the OEM 12-V battery in the LEAF?

 

[RegGuheert]

- Battery voltage with car plugged in 30 minutes after an L2 charge from 3 bars to 10 bars: 12.62 V.

Yesterday the car was on continuously for 4.5 hours and then it charged again this morning from 3 bars to 9 bars. But instead of letting the charging finish, I pulled the plug and then let the car sit for an hour before taking a measurement:

- Battery voltage with car unplugged 60 minutes after an L2 charge from 3 bars to 9 bars: 12.76 V.

At this point I will say that I am confident that our LEAF's 12-V battery is almost certainly fully charged. Once the charge timer expires at 8:00 AM this morning I intend to plug in the LEAF again and let it settle down for 30 minutes or so and take a measurement. I expect to see a lower voltage since I think the draw is higher with the plug in than with it out.

The car will not be used today, so it will be interesting to see how much the resting voltage drops with the plug in.

 

[RegGuheert]

I did a plugged-in test to see how quickly the 12V battery would get drained. I had hoped to get about five days of uninterrupted time in, but life happened and the test only lasted for 45 hours before our LEAF needed to be driven. Still, the results should get us some ballpark figures.

The battery voltage at the start of the plugged-in test, but after settling for some time, was 12.44V and had dropped to 12.36V after 45 hours. I had the charging timers set to charge only 0.5 hours each week and the timer did not occur during this test. In this region of SOC, a 10% drop in SOC equates to about 130mV, so extrapolating from 80mV in 45 hours means 130mV in 73 hours or about 3 days for a 10% drop in SOC. That means a fully-charged battery would be completely dead after 30 days if plugged in and no charging occurred (which is probably a bad assumption since SOME charging should happen). In my case, the 12V battery was not fully charged, but rather it appeared to start around 80%, meaning it would have only taken about 24 days to become fully dead.

I guess this doesn't explain why some vehicles have lost their charge while plugged in in much less than 24 days. Still, this is a little bit of data. I will try to redo this testing again when I can have longer to run the test.

 

[DaveinOlyWA]

I did a plugged-in test to see how quickly the 12V battery would get drained. I had hoped to get about five days of uninterrupted time in, but life happened and the test only lasted for 45 hours before our LEAF needed to be driven. Still, the results should get us some ballpark figures.

The battery voltage at the start of the plugged-in test, but after settling for some time, was 12.44V and had dropped to 12.36V after 45 hours. I had the charging timers set to charge only 0.5 hours each week and the timer did not occur during this test. In this region of SOC, a 10% drop in SOC equates to about 130mV, so extrapolating from 80mV in 45 hours means 130mV in 73 hours or about 3 days for a 10% drop in SOC. That means a fully-charged battery would be completely dead after 30 days if plugged in and no charging occurred (which is probably a bad assumption since SOME charging should happen). In my case, the 12V battery was not fully charged, but rather it appeared to start around 80%, meaning it would have only taken about 24 days to become fully dead.

I guess this doesn't explain why some vehicles have lost their charge while plugged in in much less than 24 days. Still, this is a little bit of data. I will try to redo this testing again when I can have longer to run the test.

i think an explanation would be probably be a combination of

**various levels of draw on the 12 volt battery making any extrapolation a dicey calculation

** non linear voltage drop as SOC declined in battery

having ZENN'd about for 3½ years using lead acid, I spent a good portion of my driving watching voltage levels of the batteries and they act very different depending on the level of current draw they were experiencing. the voltage does tend to stay higher for longer periods but then hits a point where the rate of voltage drop increases very rapidly.

 

[RegGuheert]

The current is so low (like C/600) that my readings are very close to resting voltages. Extrapolating SOC drop versus time is not impacted by voltage nonlinearities.

Previously, I had estimated the tare current draw on the LEAF battery to be C/600, but that was based on battery voltage measurements rather than direct current measurements. This morning, I measured the tare current for the LEAF 12V battery with the EVSE unplugged. Here is what I found:

- For the first ten minutes or so the car drew 330mA.
- After about 10 minutes, the tare current dropped to a lower value. It normally sat at 15mA, but pulsed up to 24mA every two seconds or so.
- Occasionally it would rise up to 115mA for a few seconds. I do not know how often this occurs.

According to this post, the pubished capacity of the factory 55B24L(S) battery is 45Ah at a 20-hr rate. Let's suppose it has about 50Ah at very low rates. If we suppose the tare current is a constant 15mA, then that equates to a discharge rate of C/4000. But since it pulses above that level, sometimes significantly so, the average current must be higher than that.

My C/600 estimate was based on how much the voltage dropped over muliple days, so it should take all tare currents into consideration. Given a battery capacity of 50Ah, that equates to an average tare current of about 80mA. That number seems a bit high based on my measurements, but perhaps there are fairly frequent excursions to currents higher than those I saw.

 

[Leafboy]

If the accessory battery is dropping below start-up threshold, then just attach a Battery Tender to it while on vacation. I have not had an issue so far, even with a 3 week vacation.

 

[DaveinOlyWA]

the voltage drop of "C/600" is against the 12 volt battery?

if so, what exactly is a C? as i understand it, its a charge/discharge rate so the the rate of discharge is equal to 1/600th the capacity of the battery. so a good battery would drain in 600 hours?? but then again, its lead acid and we cant use the entire capacity or anywhere near it so are we considering what SOC as to be the bottom limit? i would hesitate to go below 50% so if our usable C is 300 that could conceivably mean 300 hours/24 hours per day or 12.5 days?

sorry, but something has to be missing here. in all cases, a new battery should hold up at least double the time of a used battery. yours i would think is more than old enough to be considered used, so i would not go more than 4-5 days if plugged in unless you turn something off.

is it possible that where you were parked has cellular signal blocked which could reduce power usage because the car cannot communicate with Carwings?

 

[DaveinOlyWA]

If the accessory battery is dropping below start-up threshold, then just attach a Battery Tender to it while on vacation. I have not had an issue so far, even with a 3 week vacation.

if your LEAF is not plugged in, your LEAF should boost the 12 volt battery periodically so you have nothing to worry about

 

[Stanton]

is it possible that where you were parked has cellular signal blocked which could reduce power usage because the car cannot communicate with Carwings?

Actually, I envision the OPPOSITE to be true. That is, when a wireless device (in this case the Leaf) cannot "find" coverage, it launches into a constant search mode thereby draining the battery (same thing for cell phones). That's why I always check to make sure I have coverage bars in the center console when I park at the airport (or anywhere else) and why it's good to engage "airplane mode" on your phone while in the air (or marginal coverage): saves battery. Don't know if this was his problem, but it's something I pay attention to and have never had dead 12V battery problems.

 

[DaveinOlyWA]

is it possible that where you were parked has cellular signal blocked which could reduce power usage because the car cannot communicate with Carwings?

Actually, I envision the OPPOSITE to be true. That is, when a wireless device (in this case the Leaf) cannot "find" coverage, it launches into a constant search mode thereby draining the battery (same thing for cell phones). That's why I always check to make sure I have coverage bars in the center console when I park at the airport (or anywhere else) and why it's good to engage "airplane mode" on your phone while in the air (or marginal coverage): saves battery. Don't know if this was his problem, but it's something I pay attention to and have never had dead 12V battery problems.

that is a possibility but i thought Phil (who ran a 12 volt usage analysis) said that if there is no signal, the car would only check every so often which was like every 10 minutes instead of every 10 seconds.

i kinda sorta "think" i remember a lot of comments as to why Nissan felt it necessary for the LEAF to check in with Carwings so often?? but maybe i wrong on that

 

[garygid]

I believe the following to be true:

There is a 5-day timer for re-charging the 12v battery when the car is not
being used, plugged in or not.

When charging, the 12v battery is also being charged.

When the car attempts to charge, but cannot due to the battery already
being "full" (at either the 100% level or the 80% level), this 5-day timer
gets reset, even though the 12v battery has not been topped up.

So, if you want to remain plugged in for extended periods, set your charging
Timer to allow at least 5 consecutive days of no-charging during the week.

Then, the car's 12v battery should remain charged, unless there is some
excessive drain on the 12v battery.

Due to this "feature" that an ATTEMPT to charge resets the 5-day top-up
timer for the 12v battery, too-frequent futile charging attempts will inhibit
the 12v top-ups and allow the 12v battery to severely discharge.

 

[RegGuheert]

There is a 5-day timer for re-charging the 12v battery when the car is not
being used, plugged in or not.

Thanks! Your theory was one thing I had hoped to verify with this test. I had the charge timer set to charge for only 30 minutes ech week, but it got cut short before I could get to the five-day mark. I'll report back later if I manage to get a test result that goes beyond the fifth day.

 

[RegGuheert]

Oops! I had meant to quote a post earlier in this thread. Unfortunately, I edited it, erasing most of what was there originally.

Anyway, here is the post I intended to make today:

The current is so low (like C/600) that my readings are very close to resting voltages. Extrapolating SOC drop versus time is not impacted by voltage nonlinearities.

Previously, I had estimated the tare current draw on the LEAF battery to be C/600, but that was based on battery voltage measurements rather than direct current measurements. This morning, I measured the tare current for the LEAF 12V battery with the EVSE unplugged. Here is what I found:

- For the first ten minutes or so the car drew 330mA.
- After about 10 minutes, the tare current dropped to a lower value. It normally sat at 15mA, but pulsed up to 24mA every two seconds or so.
- Occasionally it would rise up to 115mA for a few seconds. I do not know how often this occurs.

According to this post, the pubished capacity of the factory 55B24L(S) battery is 45Ah at a 20-hr rate. Let's suppose it has about 50Ah at very low rates. If we suppose the tare current is a constant 15mA, then that equates to a discharge rate of C/4000. But since it pulses above that level, sometimes significantly so, the average current must be higher than that.

My C/600 estimate was based on how much the voltage dropped over muliple days, so it should take all tare currents into consideration. Given a battery capacity of 50Ah, that equates to an average tare current of about 80mA. That number seems a bit high based on my measurements, but perhaps there are fairly frequent excursions to currents higher than those I saw.

 

[KillaWhat]

Kind of lame. I thought the main battery was supposed to keep the 12V charged. Maybe it only does this when the car is on?

It will, but not with the EVSE connected.
There are threads all over the place on here about this.

But I'll summarize.
Charge the leaf, but not over 80%
Unplug it.
Go on vacation
Come back.
Drive Leaf.

There you go!

 

[evnow]

It will, but not with the EVSE connected.
There are threads all over the place on here about this.

But I'll summarize.
Charge the leaf, but not over 80%
Unplug it.
Go on vacation
Come back.
Drive Leaf.

There you go!

Resurrecting this old thread ...

Unfortunately the above isn't correct. I left my '13 for 19 days - charged to 80%, unconnected to EVSE. Leaf was completely dead when I returned - and had to jump start the car, leave it on for 40 minutes (manual says 20 minutes) before the 12v battery got charged enough to let me re-start Leaf.

Looks like we have to disconnect the battery or(and ?) put it on a tender.

 

[Leafboy]

My Leaf is a 2011. I usually only charge it to 80%. I have left it many times, some for a two week stretch. It has the orgional 12v battery and I have never had a problem with starting issues. I do keep it plugged in when I leave it. I never leave it unplugged for any reason if it is in my garage.

 

[bowthom]

Hello,
I'll chime in too. Have left my 2011 leaf for 2 weeks, unplugged, at 50% charge a few times and all is well when I return. Battery at 50% etc. Car turned on fine, however, I did not check the status of the 12V battery before driving it. Next time I will.

 

[Berlino]

There are threads all over the place on here about this.

But I'll summarize.
Charge the leaf, but not over 80%
Unplug it.
Go on vacation
Come back.
Drive Leaf.

What if the LEAF is parked outside and it will be -4F or lower for the week you'll be gone?