The issue of no Cool Air in "ON" Mode until 12 volt battery depletes

[Electryic]

I'm a rideshare driver and much of my range gets used waiting for a call with the climate control on.

The issue is that the AC (cool air) won't work until the 12 volt drops to a certain point, at which point the main battery kicks in and starts recharging the 12 volt battery. While the main battery recharges the 12 volt, the AC works, but not until the 12 volt battery is depleted.. until then even though Climate Control is on in "On" mode.. you are only getting the Fan.. there is no Air Conditioning.

What I have found is that you use about 5-6 miles of range per hour sitting with the AC on in "ON" Mode (not "ready to drive").. that's once the 12 volt drops and the main battery kicks in.

Here's the issue that I am hoping someone might have some new info on: *Most* of the time, if I take a nap or something waiting for a call, everything is fine.... once the main battery kicks in, it stays on, and keeps the cabin nice and cool while it uses about 5 miles of range per hour.

This is good, as recharging is not an issue at all, there are plenty of quick charge stations around my area. The problem is that every once in a while, for some reason or another, the main battery will disengage, I assume probably because it reads that the 12 volt battery is at a sufficient level, so no longer needs charging. The problem with this of course, is that if I'm taking a nap, the AC suddenly turning off brings the cabin up to a dangerous level of heat.

I am wondering if anyone has any further info on this.. i.e. possibly being able to keep the main battery on in "ON" mode.
The issue with keeping it in Drive mode is that it appears to use the battery much much faster.

 

[Firetruck41]

I just leave it in "drive" mode, it doesn't seem to use all that much energy for the A/C, maybe a couple percent per hour. I make sure headlights, etc are off, if I am sitting with the AC on for a while. I don't want to stress the 12v batt or get stranded, as 12v charging is notoriously weak on the Leaf.

 

[jpadc]

I'm a rideshare driver and much of my range gets used waiting for a call with the climate control on.

The issue is that the AC (cool air) won't work until the 12 volt drops to a certain point, at which point the main battery kicks in and starts recharging the 12 volt battery.

That is really hard on your 12 volt battery and you are likely to get yourself "stuck" in that the car won't take over charging before the 12 volt battery is too low to make the car "Ready." I'm actually surprised it works at all. You should just leave the car in Ready mode all the time you're sitting and waiting.

 

[Electryic]

Thanks for the advice. I will try leaving it in Drive rather than "ON" I was under the impression that in Drive mode other systems are engaged that use alot more energy than if your in ON.

Regarding the 12 volt battery.. . I'm pretty sure the main battery kicks in well before the 12 volt is down to a level that will negatively impact it. "Depleted" was not a good choice of words... I think its more like as soon as the 12 volt can benefit from being charged, the system probably kicks in. I doubt the Leaf would be designed to wait until the 12 volt is at a point that could degrade its overall lifespan to then kick in the main recharge system.

I will try leaving it in Drive though and see how it effects the range. Right now in "ON" it seems to use about 7% per hour.

 

[jpadc]

Regarding the 12 volt battery.. . I'm pretty sure the main battery kicks in well before the 12 volt is down to a level that will negatively impact it. "Depleted" was not a good choice of words... I think its more like as soon as the 12 volt can benefit from being charged, the system probably kicks in. I doubt the Leaf would be designed to wait until the 12 volt is at a point that could degrade its overall lifespan to then kick in the main recharge system.

You won't have to spend much time on this site to learn that many (but by no means all) members here have found (after very careful tracking) the LEAF 's 12 volt charging algorithm completely inadequate under "normal use" resulting in premature battery failures. Here is just one example:

http://www.mynissanleaf.com/viewtopic.php?t=19471

And you will also find lots of threads here about how a low 12 volt battery level will result in the car acting very strangely. Again just one example

http://www.mynissanleaf.com/viewtopic.php?t=19282

Some more things will require some power in "Ready" mode like the power steering (don't turn the wheel) and, of course the AC will cool all the time (unless you cycle it) but you will save yourself a lot of grief.

 

[TimLee]

... I'm pretty sure the main battery kicks in well before the 12 volt is down to a level that will negatively impact it. "Depleted" was not a good choice of words... I think its more like as soon as the 12 volt can benefit from being charged, the system probably kicks in. I doubt the Leaf would be designed to wait until the 12 volt is at a point that could degrade its overall lifespan to then kick in the main recharge system.
...

I thought that too but learned that the LEAF On mode was incompetently designed.

It lets the 12V sag very low 10.8V if I recall correctly.
Did what you are doing but just for listening to tadio in garden and first 12V died in two years and was replaced free under the 3 year 36,000 mile warranty.

Ready mode does use a bit more power but only correct way to do what you want.

If you have 2011 or 2012, keep in mind that you cannot just sleep with AC in Auto at a normal set point.
Because any setting >60F it also can run the heat some which is another design error.

Someone in Norway is selling a plug and play cable kit for the 2011 and 2012 with switch with off low heat and full heat postions that appears to be a good solution to the problem.

See http://www.mynissanleaf.com/viewtopic.php?f=37&t=20446.

 

[GerryAZ]

Electryic,

What year and model Leaf do you have? The 2011s and 2012s will turn the resistance heater on without warning if the cabin temperature set point is higher than ambient temperature. Also, the controller will turn the heater on under certain combinations of ambient temperature and cabin temperature set point with the A/C running. The power draw of the resistance heater will reduce range significantly. The 2013 and later models have better HVAC controls which allow the driver to keep the heater turned off while still having ventilation. If you have a 2011 or 2012, you may want to consider the kit being offered by someone in Norway.

As Tim noted in an earlier post, the 2011/2012s will let the 12-volt battery discharge very deeply in ON mode before turning on the main contactor to allow the DC-DC converter to recharge it. The later models may not be as bad, but I have not checked the 2015.

Gerry

 

[Electryic]

... I'm pretty sure the main battery kicks in well before the 12 volt is down to a level that will negatively impact it. "Depleted" was not a good choice of words... I think its more like as soon as the 12 volt can benefit from being charged, the system probably kicks in. I doubt the Leaf would be designed to wait until the 12 volt is at a point that could degrade its overall lifespan to then kick in the main recharge system.
...

I thought that too but learned that the LEAF On mode was incompetently designed.

It lets the 12V sag very low 10.8V if I recall correctly.

.

Right but is that necessarily a design flaw? The Leaf doesn't require anything close to the 12V needed to start an ICE.
Would some people's report of issues actually indicate a design flaw in the Leaf?
What is the maximum draw on the 12V? Surely its nothing even in the ballpark of the full 12V that a regular car needs to start.
From my experience, it seems that the main power oversees everything, including keeping the 12V battery sufficiently charged for those times when the car is in ON/Accessory.

Is the 12V battery really needed to "start" the computer? That sounds a little odd. I would guess that the car could probably operate without the 12V battery completely, aside from a few safety features that keeps the main power in check in case of emergency etc.

And even if the 12V battery is needed to "start" the car... I highly doubt it is anywhere close to the 12V needed to start a combustion engine.
Would be happy to hear anyone's thoughts on this, as I'm not an expert.

 

[dhanson865]

... I'm pretty sure the main battery kicks in well before the 12 volt is down to a level that will negatively impact it. "Depleted" was not a good choice of words... I think its more like as soon as the 12 volt can benefit from being charged, the system probably kicks in. I doubt the Leaf would be designed to wait until the 12 volt is at a point that could degrade its overall lifespan to then kick in the main recharge system.
...

I thought that too but learned that the LEAF On mode was incompetently designed.

It lets the 12V sag very low 10.8V if I recall correctly.

.

Right but is that necessarily a design flaw? The Leaf doesn't require anything close to the 12V needed to start an ICE.
Would some people's report of issues actually indicate a design flaw in the Leaf?
What is the maximum draw on the 12V? Surely its nothing even in the ballpark of the full 12V that a regular car needs to start.
From my experience, it seems that the main power oversees everything, including keeping the 12V battery sufficiently charged for those times when the car is in ON/Accessory.

Is the 12V battery really needed to "start" the computer? That sounds a little odd. I would guess that the car could probably operate without the 12V battery completely, aside from a few safety features that keeps the main power in check in case of emergency etc.

And even if the 12V battery is needed to "start" the car... I highly doubt it is anywhere close to the 12V needed to start a combustion engine.
Would be happy to hear anyone's thoughts on this, as I'm not an expert.

Yes, the 12V is required to start the computer AND to connect the main battery.

No the car can't operate without a 12v battery if you took the 12v out of the loop you wouldn't have a working dash, headlights, radio, turn signals, etcetera.

When the car is OFF the main battery is disconnected.

If the 12v dies the car will NOT turn on.

Computers don't work reliably if the input voltage is too low. You are guaranteed to have issues if you let the 12v get low. It isn't that you might have issues, You will have issues.

You might want to grab a CTEK 3300 and charge the 12V manually in addition to the Leafs charging.

You definitely need to check the fluid levels in the battery as the Leaf OEM battery isn't sealed and your past usage habits were abnormal enough that you may have gotten the battery low enough that it has received permanent damage. Keeping the fluid up and using a desulphinating charger might prolong the 12V usable life.

Whatever you do take this seriously and check and maintain the 12V if you don't want to call a tow truck.

 

[GerryAZ]

The 12-volt battery is needed to power the various control modules (computers), the brakes, power steering, HVAC fan, and the main contactor that connects the traction battery to the DC-DC converter (which charges the 12-volt battery) and high-voltage power modules which supply the traction motor, heat pump or A/C compressor, and resistance heater. The car will not start (boot up) if the 12-volt battery is too low or too weak to power the computers and close the main DC contactor.

A relatively new battery that is discharged may be able to supply enough current at low voltage to start the car while an old, weak battery may not be able to supply enough current to boot the car even with no-load voltage that appears normal. This is why we recommend periodic load testing of the 12-volt battery to avoid getting stranded by a simple 12-volt battery failure.

As noted by several experienced LEAF drivers earlier in this thread, use READY mode to run the HVAC system while parked to avoid deep cycling the 12-volt battery and unnecessary opening/closing of the main DC contactor.

Gerry

 

[TimLee]

... Right but is that necessarily a design flaw? ...

It is a design flaw because letting the 12V battery sag that low substantially shortens its service life.

Bad design practice to give the customer an operating mode they presume is OK, when in reality they are substantially shortening the 12V battery life.

And then to make it worse the LEAF does a poor job of recognizing the 12V battery is bad.
Instead it continues to operate in an unsafe manner with dangerous bad effects like scary no braking.

Horribly bad design.

 

[Levenkay]

Computers don't work reliably if the input voltage is too low. You are guaranteed to have issues if you let the 12v get low. It isn't that you might have issues, You will have issues.

Five volts is the highest supply voltage used by a cursory Googling of automotive-rated microcontrollers that I can see. One thing that still has me completely stumped by all these reports of 12V battery degradation sending LEAF control systems into software la-la land is: What kind of lack-wits can't come up with a 5V (or more likely, 3V) computer supply that'll hold up from even a 6V rail? Or at the very least, hold up long enough to notice that power is failing and to set an error code to that effect?

 

[Electryic]

Thanks for the heads up. I am still slightly concerned with leaving it in Ready mode for extended periods. Would you guys suggest keeping an eye on anything else .. example being like power steering fluid... since it appears the power steering is engaged in Ready mode.

Basically at times I am keeping it in Ready mode for sometimes up to a couple hours while I nap waiting for a call. If anyone has any other suggestions of things to keep an eye on in terms of maintenance or what is being used in Ready mode, I'd appreciate it.

 

[GerryAZ]

Keep it in Park with the doors locked. The power steering is electric and has no fluid to worry about.

Gerry

 

[TimLee]

I leave the 2011 electric parking brake double set.

I leave it in Ready to keep the AC running while away from the vehicle sometimes.
Just be sure you've used the door button to lock it :shock: :!:
And yes, if someone breaks the window or uses tool to unlock the door they can drive it away :shock:

 

[knightmb]

I leave the 2011 electric parking brake double set.

I leave it in Ready to keep the AC running while away from the vehicle sometimes.
Just be sure you've used the door button to lock it :shock: :!:
And yes, if someone breaks the window or uses tool to unlock the door they can drive it away :shock:

I've read that a lot here, but when I tried it on my 2013, (with no key fob present), it just puts the car in neutral, unable to "steal" it, so is this a design flaw on just the earlier 2011 or 2012 models?

 

[TimLee]

...
I've read that a lot here, but when I tried it on my 2013, (with no key fob present), it just puts the car in neutral, unable to "steal" it, so is this a design flaw on just the earlier 2011 or 2012 models?

The LEAF has to recognize the key fob for the lock / unlock button on the door handle to function.

 

[knightmb]

...
I've read that a lot here, but when I tried it on my 2013, (with no key fob present), it just puts the car in neutral, unable to "steal" it, so is this a design flaw on just the earlier 2011 or 2012 models?

The LEAF has to recognize the key fob for the lock / unlock button on the door handle to function.

How does that allow someone to drive away with the vehicle (steal it) when it is already powered on?

I regularly leave my Leaf running with the AC on when I make a quick stop into the post office or other places because I know someone can't come in behind me, get in the vehicle and drive off without my key. Is this behavior different on the earlier model years? A lot of vehicles are stolen when the owner leaves the vehicle running, goes into a convenience store for example, someone hops in the vehicle and drives away gas vehicles for example.

 

[Firetruck41]

Yes, you can drive off without the keys if the car is left in "ready" mode. I did it right after we got the car and my wife left it on while we switched cars (she had the key in her purse), and I drove it several miles with no key in the car. There was a warning on the dash that there was no key sensed in the car. This was in a 2013.

 

[Firetruck41]

I regularly leave my Leaf running with the AC on when I make a quick stop into the post office or other places because I know someone can't come in behind me, get in the vehicle and drive off without my key. Is this behavior different on the earlier model years? A lot of vehicles are stolen when the owner leaves the vehicle running, goes into a convenience store for example, someone hops in the vehicle and drives away gas vehicles for example.

I wouldn't do that, see my post above. Now if you lock the car when you leave it, you at least have that measure of safety in place.