Leaf is dead after vacation...

[RegGuheert]

keep in mind; this battery does not turn an engine over so charging it for "hours" is a waste of energy. i would charge it no more than 15-20 minutes assuming you are back from your trip and will resume daily driving.

Allowing a lead-acid battery to sit for even a few days at below 100% SOC can cause irreversible capacity loss in the battery. This is because the lead sulfate which is formed during the discharge reaction will harden to the point where it will never again participate in the charge reaction. The rate at which the lead sulfate hardens is a function of temperature. If the battery is hot, the lead sulfate can harden in as little as three days.

FWIW, ICE vehicles are carefully designed so that the lead acid battery gets fully charged soon after the vehicle is started. This way even if the car takes short trips it does not sit at any SOC below 100% for a long period of time.

 

[TonyWilliams]

input charge voltage to lead acid is usually 14.4 volts. a "12 volt" battery that reads 12 volts is nearly dead. lead acid cells run about 2.2-2.3 volts per cell or a minimum of 13.2 volts. keep in mind; this battery does not turn an engine over so charging it for "hours" is a waste of energy. i would charge it no more than 15-20 minutes assuming you are back from your trip and will resume daily driving.

Again, generic XX minutes of charge with no data on actual starting and ending open current resting voltage is just a guess.


****Flooded Lead Acid Battery SOC at Resting Voltage and 80f (Source Trojan Battery)*****
100% = 12.73
90% = 12.62
80% = 12.50
70% = 12.37
60% = 12.24
50% = 12.10
40% = 11.96
30% = 11.81
20% = 11.66
10% = 11.51

 

[TonyWilliams]

One side note; it won't matter if the heater is on or off. The car will automatically heat or cool the car to 25C / 77F degrees.

Is that how it works? I didn't know that! Then that could be a problem if you did this with a low traction battery in 10F weather!

Well, only an absolute problem if you're charging at 100-120 volts at 12 amps and the heater load exceeds that. For a 200-240 volt 16 amp charge, the car's heater isn't likely to pull more power than that continuously unless the door or window is left open. At some point, the cabin will stabilize at 77F, and hopefully will draw less than 3000 watts. But, maybe not !!!! Caveat emptor !!!

 

[SanDust]

But, Reg claims that if you want to charge your traction battery AND you 12V battery while plugged in, use the remote app to turn on climate control. This will both engage the EVSE AND charge the 12V battery.

I haven't looked but you have to expect that the charger runs off the 12v, which means the 12v has to be charged whenever the traction battery is being charged, probably with a separate charger. I don't doubt that the 12v will be charged if you use a remote app to turn on climate control, but I expect it would also be charged if you just plugged it in.

 

[QueenBee]

but I expect it would also be charged if you just plugged it in.

One would certainly expect that, huh? It's pretty clearly evident by the recurrences of this issue that the complicated system is not getting the job done.

 

[TonyWilliams]

But, Reg claims that if you want to charge your traction battery AND you 12V battery while plugged in, use the remote app to turn on climate control. This will both engage the EVSE AND charge the 12V battery.

I haven't looked but you have to expect that the charger runs off the 12v, which means the 12v has to be charged whenever the traction battery is being charged, probably with a separate charger. I don't doubt that the 12v will be charged if you use a remote app to turn on climate control, but I expect it would also be charged if you just plugged it in.

A case of applying logic to an illogical situation !!!! Sorry, doesn't work that way.

 

[SanDust]

A case of applying logic to an illogical situation !!!! Sorry, doesn't work that way.

Which part or parts? Does the charger not run off the 12v?

 

[TonyWilliams]

A case of applying logic to an illogical situation !!!! Sorry, doesn't work that way.

Which part or parts? Does the charger not run off the 12v?

Well, I don't know!!!! But, we do know that the 12 volt battery isn't being charged when left plugged in after NUMEROUS reports of dead 12 volts while left plugged in. I leave my car stored unplugged and put the 12 volt on a battery tender.

 

[SanDust]

Well, I don't know!!!! But, we do know that the 12 volt battery isn't being charged when left plugged in after NUMEROUS reports of dead 12 volts while left plugged in. I leave my car stored unplugged and put the 12 volt on a battery tender.

Not questioning the reports. I don't, however, see a dead 12v as being inconsistent with it being charged when the traction battery is. After the charging event the 12v wouldn't be discharged. If there are sufficient parasitic losses over a long enough period of time after charging is complete the 12v would end up dead as a doornail. The critical event(s) would occur after charging not during.

Your solution of using the tender will of course work. I'm just questioning the need for the remote app and the accessories.

I'll test it after and before a charge. If it's higher afterwards then obviously it's being charged. If it's the same then either the 12v is not running the charger or the charger is just maintaining it. If it's lower then it's running the charger and not being charged, but I'd be very surprised to find this.

 

[QueenBee]

I'll test it after and before a charge. If it's higher afterwards then obviously it's being charged. If it's the same then either the 12v is not running the charger or the charger is just maintaining it. If it's lower then it's running the charger and not being charged, but I'd be very surprised to find this.

Check out the service manual. It goes into detail about exactly how long and when the 12 volt battery is charged. It seemed really complicated and it seems like they missed the mark for when someone simply plugs the car in and leaves it.

 

[RegGuheert]

Not questioning the reports. I don't, however, see a dead 12v as being inconsistent with it being charged when the traction battery is. After the charging event the 12v wouldn't be discharged. If there are sufficient parasitic losses over a long enough period of time after charging is complete the 12v would end up dead as a doornail. The critical event(s) would occur after charging not during.

Your solution of using the tender will of course work. I'm just questioning the need for the remote app and the accessories.

I think you are correct on all counts, but I will point out that using climate control instead of the charging feature has two benefits: 1) You can turn it on and leave it on even when the battery is fully charged (understood that may also be a drawback!) and 2) it can be turned off. It is the only way I know to both start AND stop charging of the LEAF remotely.

I'll test it after and before a charge. If it's higher afterwards then obviously it's being charged. If it's the same then either the 12v is not running the charger or the charger is just maintaining it. If it's lower then it's running the charger and not being charged, but I'd be very surprised to find this.

More simply you can just measure the voltage *during* charging. If it is ~13V or above, then it is charging. (It's possible this is not true at very low SOC's, but since the DC/DC converter can put out over 130A, it will get to 13V pretty quickly!) I just checked and it charges the 12V battery while the car is charging.

Ultimately I think the posters who plug into L1 while gone and have the car charge just enough each day to get back to 80% or so when they return have the best approach, since it maximizes 12V charging time and keeps the SOC on the traction battery in the middle of the range during the sitting period while still charging the battery for the return. They can trigger it to go to 100% remotely before boarding their return flight, if needed.

 

[GerryAZ]

The 12V battery is charged during charging of the traction battery and when the car is in normal running mode. It is not charged when the car is plugged-in but not charging.

The DC-DC converter puts out a little over 14V (exact value depends on temperature) to quickly charge the battery after powering on the car. Once the 12V battery is charged enough to cause the charging current to drop to a low level, the DC-DC converter drops the charging voltage to 13.0-13.4 (depending on temperature) to avoid overcharging the small battery.

I routinely leave my Leaf unplugged at about 60% SOC for extended periods of time at my office or the airport and have never had a problem. The amount of energy drawn from the traction battery every few days to charge the 12V battery is so small that I have never seen more than the 1 SOC bar difference between parking and returning that is normal due to just turning the car off and back on.

Gerry

Edited to delete statement about not charging in accessory mode.

 

[MikeD]

GerryAZ: I have found that the 12v battery can actually be charged in "Accessory Mode", but only, I think, when the traction battery is being charged. So someone might want to listen to the radio while the car is being charged -- without having the normal worry at other times that listening to the radio in "Accessory Mode" is excessively discharging the 12v battery.

 

[GerryAZ]

GerryAZ: I have found that the 12v battery can actually be charged in "Accessory Mode", but only, I think, when the traction battery is being charged. So someone might want to listen to the radio while the car is being charged -- without having the normal worry at other times that listening to the radio in "Accessory Mode" is excessively discharging the 12v battery.

You are probably right. I have never been able to get it into a mode that will charge the 12V battery and run climate control with it plugged in, but others have noted that it is possible to run climate control (without using t6he remote app). If it is possible to run climate control while plugged-in, the 12V battery would probably charge.

Gerry

 

[planet4ever]

I'm not sure which mode MikeD was referring to, but I think many of us find it very confusing that there is what Nissan calls an ON mode (that is often called an accessory mode) and also an ACC mode.

• ACC: Press power button once with foot off the brake. Central console lights up, but dash doesn't.
• ON: Press power button a second time with foot off the brake, or press power button once when plugged in and foot on the brake. Dash and console both light up, but there is no green car showing on the dash and you can't shift into gear.
• READY: Press power button once with foot on the brake and not plugged in. This is the only mode you can drive in.

I know the radio works in all three of these modes, but the windows work only in ON and READY modes. I'm fairly certain you can't get any heating or cooling of air in ACC mode, but the fan might work. I don't know which ones allow charging.

Ray

 

[davewill]

I'm not sure which mode MikeD was referring to, but I think many of us find it very confusing that there is what Nissan calls an ON mode (that is often called an accessory mode) and also an ACC mode. ...

They are the same "modes" that a regular car has. You can turn the key partway to get "ACC" mode (mainly just the radio works), you can turn the key to "ON" mode (windows and other stuff works), or can depress the brake and start the engine for "READY" mode (you can drive).

 

[RegGuheert]

I'm not sure which mode MikeD was referring to, but I think many of us find it very confusing that there is what Nissan calls an ON mode (that is often called an accessory mode) and also an ACC mode.

I certainly didn't get it until you explained it to me previously. I wrote up the confusion over the modes and the poor explanations in the manual of how the different modes are triggered in my JD Power survey response.

I don't know which ones allow charging.

If you are referring to 12V battery charging, I know that READY mode charges the 12V battery and OFF mode allows charging if you turn on climate control remotely. I have not observed any 12V charging in ACC mode or ON mode. (Of course that doesn't mean it can't happen.)

Here's a theory: Suppose you turned off the display in the center console and put the car in ACC mode accidentally by double-pressing the main button from READY with your foot off the brake. Would that drain the battery quickly?

 

[ztanos]

I'm not sure which mode MikeD was referring to, but I think many of us find it very confusing that there is what Nissan calls an ON mode (that is often called an accessory mode) and also an ACC mode.

• ACC: Press power button once with foot off the brake. Central console lights up, but dash doesn't.
• ON: Press power button a second time with foot off the brake, or press power button once when plugged in and foot on the brake. Dash and console both light up, but there is no green car showing on the dash and you can't shift into gear.
• READY: Press power button once with foot on the brake and not plugged in. This is the only mode you can drive in.

I know the radio works in all three of these modes, but the windows work only in ON and READY modes. I'm fairly certain you can't get any heating or cooling of air in ACC mode, but the fan might work. I don't know which ones allow charging.

Ray

I know that the Altima has the exact same setup. Including having to press the brake to get it to go into "ready" mode.

 

[RegGuheert]

Here's a theory: Suppose you turned off the display in the center console and put the car in ACC mode accidentally by double-pressing the main button from READY with your foot off the brake. Would that drain the battery quickly?

According to the 2011 LEAF Owner's Manual Revised, this cannot happen:

12-VOLT BATTERY SAVER SYSTEM
When all the following conditions are met for 60
minutes, the battery saver system will cut off the
power supply to prevent 12-volt battery discharge.
. The power switch is in the ACC position,
. All doors are closed, and
. The vehicle is in the P (Park) position.

Of course, that does not mean it doesn't happen, only that it is not SUPPOSED to happen.

It is interesting that it does not say this "BATTERY SAVER SYTEM" functions in "ON" mode.

 

[MikeD]

To clarify my last post, by "Accessory Mode" I meant the documented "ACC Mode", but 12v battery charging also occurs in "ON Mode" as well. I am able to verify this by observing that a voltmeter that I leave permanently connected via the 12v accessory outlet reads ~13.1 (or ~14.4 when initially charging at a higher rate) ONLY when 1) in "READY Mode" while not car charging or 2) in "ACC Mode" or "ON Mode" when car charging.

I sometimes listen to the radio for extended periods in "ACC Mode" while not car charging, so I monitor the 12v battery's voltage and switch to "READY Mode" if necessary to prevent that battery from discharging too far (below ~11.9v).