Long Vacation - Advisable to be plugged in all the while?

[Deleted member 3147]

If you leave it plugged in, you will destroy your 12v battery.

-Phil

Phil has stated this with the emphasis it needs. I did just notice that a far weaker statement has finally been added to Page EV-24 of my 2013 Owner's Manual:

If the vehicle will not be used for an extended period of time, charge the Li-ion battery using the long life mode once every 3 months. Do not operate the charging timer repeatedly while the charge connector is connected to the vehicle after the Li-ion battery charging is completed. Doing so may discharge the 12-volt battery.

May discharge?? Make that, "is guaranteed to beat it to death".

Ray

Typical Nissan. Don't fix the bug, document it!

Old saying from the computer industry: a feature is a bug that's documented!

 

[Reddy]

I just came across a 2013 Leaf (govt plates) that has been plugged in (and not charging) for more than a week. I wasn't sure whether Nissan fixed this problem on the 2013, so did a quick search, and hah, there's the answer. I suppose it's my duty now to go talk to the people who are responsible for the vehicle. It's a shame to see an EV sitting while all the govt trucks cruise around here wasting gas.

 

[johnrhansen]

Don't let the car sit. Have one of your ICE driving friends drive it once in awhile. Hopefully it will turn them on to electric so that they will buy one too.

 

[Reddy]

Agreed. Unfortunately, I just happened to be driving by and notice a Leaf. I don't know anybody and probably can't even walk in the door without security jumping on me.

 

[DNAinaGoodWay]

Say you leave the LEAF plugged in at an airport from Friday afternoon to Monday noontime. Time the charge to finish as you're landing on Monday. Would the 12 volt do OK for that amount of time?

 

[Klayfish]

The car draws more heavily on the 12v battery when plugged in, and worse, fails to do the every 5-day charge up.

I read through this thread, and this is the only question I have. If I ever leave town for more than a few days, I'll simply disconnect my 12V. Easy enough. But I didn't realize that the car draws more heavily on the 12V when it's plugged in. Why does it do that? I would think it would draw any power it needs from the outlet?

 

[Reddy]

Say you leave the LEAF plugged in at an airport from Friday afternoon to Monday noontime. Time the charge to finish as you're landing on Monday. Would the 12 volt do OK for that amount of time?

From all I've read, yes, you should be fine over a 3-day weekend.

 

[DNAinaGoodWay]

Thanks

 

[Levenkay]

The car draws more heavily on the 12v battery when plugged in, and worse, fails to do the every 5-day charge up.

I read through this thread, and this is the only question I have. If I ever leave town for more than a few days, I'll simply disconnect my 12V. Easy enough. But I didn't realize that the car draws more heavily on the 12V when it's plugged in. Why does it do that? I would think it would draw any power it needs from the outlet?

My understanding of the issue (at only about 70% confidence level) is that the load on 12V is not heavier while you're plugged in, it's simply that the steady load that IS on the 12V must be replaced, and the policies built into the firmware for doing that replacement are curiously flawed when the car is plugged in. When you're plugged into an EVSE, the car only transfers energy from the main battery pack to the 12V system if it thinks it can do so without depleting the main battery; in other words, during those times when the main battery is being charged. But the main battery HASN'T got much of a load on it (discharge time constant on the order of a month or two, I gather), so once the main battery gets charged up to whatever its current goal is (80% or 100%, depending on settings), the main battery stops being charged, and so the 12V system gets drained without any source of resupply.

I've not needed to leave the LEAF for longer than a week or so, and I'd be the national Laziest Person Alive trophy winner (if I could just muster up the initiative to send in my entry form), so I just leave the LEAF completely unplugged with some decent 50-80% charge in its main battery. Apparently, when you're NOT plugged in, the system firmware is willing to transfer energy from the main battery to the 12V one as needed to keep the 12V system at its anemic charge level.

 

[smkettner]

Say you leave the LEAF plugged in at an airport from Friday afternoon to Monday noontime. Time the charge to finish as you're landing on Monday. Would the 12 volt do OK for that amount of time?

You could set timer 1 to charge an hour Saturday and Sunday morning for an hour or 80% then timer 2 end timer set to be charged upon return 100%.
Verify status through carwings. Has worked for me during a week trip and L1 at LAX back in the days of free parking.

 

[planet4ever]

But I didn't realize that the car draws more heavily on the 12V when it's plugged in. Why does it do that? I would think it would draw any power it needs from the outlet?

Unless I'm badly mistaken there is no 240v AC to 12v (or 15v) DC charger built in to the car. Not even a 120v AC to 12v DC charger. So the only way the 12v battery can draw power from the outlet is for the (water cooled) 240v AC to 400V DC charger to charge the traction battery and then for the (water cooled) 400v DC to 12v DC converter to draw power from the traction battery. It should be obvious that both of those processes are inefficient, and (because of pump and fan) use a significant amount of 12v energy themselves. The logic is not clear to us, but for some reason the Nissan engineers decided that the 400v to 12v converter should never run when the car was plugged in unless it was charging. On possible reason would be that if the battery was fully charged, then the occasional converter load could trigger recharging, which is precisely the case that they warn will void the warranty.

Note: I'm not disagreeing with Levenkay's response, which I believe is correct, just approaching the question from a different angle.

Note 2: All voltages are approximate.

Ray

 

[DNAinaGoodWay]

Say you leave the LEAF plugged in at an airport from Friday afternoon to Monday noontime. Time the charge to finish as you're landing on Monday. Would the 12 volt do OK for that amount of time?

You could set timer 1 to charge an hour Saturday and Sunday morning for an hour or 80% then timer 2 end timer set to be charged upon return 100%.
Verify status through carwings. Has worked for me during a week trip and L1 at LAX back in the days of free parking.

Interesting. Might try that, thanks.

Could you expand that into a longer term plugged in strategy? Leave the car plugged in at some low SOC, say 30-40%, with timer 1 set for a half hour, every other day, but no timer 2. Then, use Carwings to top it off when you're coming back. Or, something like that? Might be able to get 2 weeks out of it?

 

[Mmen]

Just a question I can't seem to find an answer to on the threads on this topic.
I try to top off my 12v battery with a battery tender. (I made an extension to the wires and have it going all the way to the regular charging port so I do not need to pop the hood every time.)
Is it ok to have the car plugged in - but not charging - while the battery tender does it's job, and at 5:00 in the morning the charger starts charging the main traction battery while the battery tender is still plugged in? I thought I read somewhere that something gets messed up if both of them are plugged in together, but I can't seem to find I clearly where the problem is.
Thank you anyone for clarifying this for me.

 

[smkettner]

I don't think you will have any issues.

 

[LeftieBiker]

It probably depnds on which Battery Tender you are using. The 0.75 amp BT Jr. might not always keep up, while a larger unit, with more than one amp output, should.

 

[QueenBee]

It probably depnds on which Battery Tender you are using. The 0.75 amp BT Jr. might not always keep up, while a larger unit, with more than one amp output, should.

.75 amp will have no trouble keeping up with the little bit of draw from the LEAFs computers before they go to sleep...

 

[QueenBee]

It probably depnds on which Battery Tender you are using. The 0.75 amp BT Jr. might not always keep up, while a larger unit, with more than one amp output, should.

.75 amp will have no trouble keeping up with the little bit of draw from the LEAFs computers before they go to sleep...

Specifically Ingineer recommends this .8 amp charger: http://www.amazon.com/gp/aw/d/B006CQ9BMO/ref=mw_dp_mpd?pd=1" onclick="window.open(this.href);return false;

 

[apvbguy]

I was away for 10 weeks last year, I left the car unplugged at 50% and returned to a car with 50%. I charged it up and drove it like I was never away. YMMV

 

[Mmen]

Well, I tried it out last night, j1772 plugged in with the battery tender and it was NOT able to keep up. I have the Battery Tender Jr. which gives out .750 amps, and after 12 hours the red light was still on. Next time I will try not to have them both plugged in at the same time.
Oh well...

 

[QueenBee]

Well, I tried it out last night, j1772 plugged in with the battery tender and it was NOT able to keep up. I have the Battery Tender Jr. which gives out .750 amps, and after 12 hours the red light was still on. Next time I will try not to have them both plugged in at the same time.
Oh well...

Probably not that it couldn't keep up, probably just that it was still charging the battery. I'm sure it actually was charging the battery the whole time.