Long Term Leaf Storage

I been scouring the blogosphere here for tips on long term storage of my Leaf.
Most discussions I've found consider 'long term' to be 2-3 weeks.
How about months?
I will be traveling overseas soon, and will be gone for 3-4 months.
In this case, what would be recommended?
50% charge, unplugged?
80% charge, plugged in?
Perhaps 80% charge, plugged in, and timer set for once a week?
Any thoughts and experiences would be appreciated.
Thanks!

P.S...how about the 12V battery?
Get a trickle-charge for it like I have for my now dormant Infiniti?
Or, does the main charger take care of that?

I stored mine for 6-7 weeks, at 50% charge, unplugged.

When I came back later to get the car, it had not depleted. The CarWings system won't be able to find the car after a while, but all went well.

I would recommend leaving it unplugged so that the 12v accessory battery will periodically receive a booster charge from the large battery....

Randy

Make sure you do not set alarm. Have known a lot of people that did just that with ice vehicles and battery depleted fast.

Not a problem on the Leaf.

walter said:

Make sure you do not set alarm. Have known a lot of people that did just that with ice vehicles and battery depleted fast.

Click to expand...

Someone can answer this for sure but reading the manual seems to hint that the 12v battery is monitored and if the vehicle is plugged in, it will recharge if necessary. This doesn't apply to the main battery, just the aux battery. If it is not plugged in, it doesn't appear that it can be recharged while the car is sitting via the DC to DC converter. If I park the car for any time period, I use a small 1 amp trickle charger to keep the aux battery charged. There seems to be a .1 to .2 amp draw on the 12v battery when the car is idle.

walter said:

Make sure you do not set alarm. Have known a lot of people that did just that with ice vehicles and battery depleted fast.

Click to expand...

what alarm?

kraff55 said:

I been scouring the blogosphere here for tips on long term storage of my Leaf.
Most discussions I've found consider 'long term' to be 2-3 weeks.
How about months?
I will be traveling overseas soon, and will be gone for 3-4 months.
In this case, what would be recommended?
50% charge, unplugged?
80% charge, plugged in?
Perhaps 80% charge, plugged in, and timer set for once a week?
Any thoughts and experiences would be appreciated.
Thanks!

P.S...how about the 12V battery?
Get a trickle-charge for it like I have for my now dormant Infiniti?
Or, does the main charger take care of that?

Click to expand...

From the owner's manual of my 2011 LEAF, page Ev-3:
"The Li-ion battery discharges gradually if the
vehicle is parked for a long time. NISSAN
recommends charging the Li-ion battery every
3 months using the long life mode charging
method to keep the Li-ion battery in good
condition. Do not leave the Li-ion battery fully
discharged or with a very low charged level for a
long period of time."

The "long life" charging mode merely means setting the charging timer(s) to charge to 80% instead of to 100%, as on page CH-20:
"NISSAN recommends charging the Li-ion battery
using the long life mode to help maximize
the Li-ion battery useful life.
Long life mode can only be set using the
charging timer function.
The long life mode is set by changing the [%
Charge] to [80% Charge (Improves Battery
Longevity)] using the following procedure."

Last winter I left my 2013 LEAF in the garage undriven from mid-January until the beginning of May. I left the traction battery charged at 50% according to the display and disconnected the 12 V battery. The SOC was 41% when I returned, and I had no problems after reconnecting the 12 V battery. The conventional wisdom on this forum is that the ideal charge for storage is around 40-50%, based on published Li battery data. However, the LEAF 2013 manual recommends storage at 80% charge, recharging to 80% every 3 months.

My first capacity readings were around 64 Ah (Leaf Spy) in mid-September 2013, 6 weeks and 850 miles after buying the car (ordered, it did not sit charged on the lot. Some 2103 LEAFs have been reported to arrive with slightly lower measured capacity than 2012 but similar range.) When I left in January 2014 after 3000 miles it was still reading 64 – I suspect overcompensation for cold temperatures because there had been earlier readings down to 62.

My first reading after returning in May 2014 was 59 Ah. I thought the battery would be very happy chilling during on our unusually cold 2014 winter (lowest outside low temperature around 5°F, a bit warmer in the unheated garage) at what I thought was an ideal 50% charge level, so I was surprised to see this large drop. But it may well be some kind of artefact, because capacity has been steady at around 59 since May (health also steady at about 90%). (The battery gets deluxe treatment, charged mostly at 80% and no QC. We had only a few days last summer over 90°F, and on summer nights I open the garage windows and pull in cooler air with a gable fan.) If the baseline reading was 64 (i.e. no significant loss in the first 6 weeks), the capacity loss to date is 8% over 16 months and 8500 miles, close to expectation for NJ.

So like the OP, my question is, for future winter storage should I go with the Nissan manual and charge to 80%, or is 50% better?

Loan it to someone you can trust, problem solved!

JonathanT said:

So like the OP, my question is, for future winter storage should I go with the Nissan manual and charge to 80%, or is 50% better?

Click to expand...

All available data on lithium batteries says that 50% should be better than 80% for long term storage. I'd chalk your Ah reading anomalies up to just that - anomalies in the way the BMS estimates capacity of the battery pack.

I have done this before leaving the Leaf unattended for 2-3 mths.
Charge it to 80%. Leave it unplugged. Park the vehicle outside on your driveway where the sun can shine on the rear solar panel. Let the solar panel keep the 12V aux battery charged.
You'll lose 2-3 bars when you get back after 3 mths but that's normal.

kraff55 said:

I been scouring the blogosphere here for tips on long term storage of my Leaf.
Most discussions I've found consider 'long term' to be 2-3 weeks.
How about months?
I will be traveling overseas soon, and will be gone for 3-4 months.
In this case, what would be recommended?
50% charge, unplugged?
80% charge, plugged in?
Perhaps 80% charge, plugged in, and timer set for once a week?
Any thoughts and experiences would be appreciated.
Thanks!

P.S...how about the 12V battery?
Get a trickle-charge for it like I have for my now dormant Infiniti?
Or, does the main charger take care of that?

Click to expand...

mxp said:

I have done this before leaving the Leaf unattended for 2-3 mths.
Charge it to 80%. Leave it unplugged. Park the vehicle outside on your driveway where the sun can shine on the rear solar panel. Let the solar panel keep the 12V aux battery charged.
You'll lose 2-3 bars when you get back after 3 mths but that's normal.

Click to expand...

The solar panel does not "keep the 12V aux battery charged". In your case, the 12V battery was kept charged by the traction battery. But it also got abused at the same time, since the traction battery only "charges" the 12V battery once every 5 days, and even then it does not come close to fully charging it.

There have been reports here of the 12V battery dying while parked outside in the sun unplugged.

If you are going to leave your LEAF for more than a week, I recommend the following:
- Charge the EV battery to between 30% and 50% SOC.
- Unplug the EVSE.
- Disconnect the 12V battery.
- Charge the 12V battery to full using a high-quality trickle charger.
- If you will be gone for a month or more, leave the 12V battery on a high-quality trickle charger.

drees said:

JonathanT said:

So like the OP, my question is, for future winter storage should I go with the Nissan manual and charge to 80%, or is 50% better?

Click to expand...

All available data on lithium batteries says that 50% should be better than 80% for long term storage. I'd chalk your Ah reading anomalies up to just that - anomalies in the way the BMS estimates capacity of the battery pack.

Click to expand...

Yes, I'll go with that, thanks. Any idea why Nissan doesn't also advise 50%?

JonathanT said:

Yes, I'll go with that, thanks. Any idea why Nissan doesn't also advise 50%?

Click to expand...

For the reason that Reg mentioned above - for really long term storage the main battery will eventually drain down as the car wakes up periodically to charge up the 12V battery, which will slowly drain the main battery. You really need to leave the car parked a long time for this to be an issue, though. A couple months will be fine. And if you disconnect the 12V battery, the car won't wake up to charge the 12V battery so the main battery will discharge very little over even very long periods of time.

Reg,
I disagree with your comment. The Solar Panel does help maintain the 12V aux battery. I will add that it won't recharge a depleted 12V battery, IIRC. And, those reports, I recall, with the 12V battery dying were the ones kept indoors and with the charge plug inserted.

Again, I have done what I did with both my 2011 Leafs and they work fine even after 3 months of not driving them. They've only lost 2-3 bars when I turned them back on again.

To each his own, I'll stick to what worked for me.

RegGuheert said:

< cut >
The solar panel does not "keep the 12V aux battery charged". In your case, the 12V battery was kept charged by the traction battery. But it also got abused at the same time, since the traction battery only "charges" the 12V battery once every 5 days, and even then it does not come close to fully charging it.

There have been reports here of the 12V battery dying while parked outside in the sun unplugged.

Click to expand...

So...leaving for 6 months...have a great state-of-the-art trickle charger.
Will have the LI battery at 50% isn, and leave the charger unplugged.
But, my question is...if you have a great trickle charger...WHY detach the lead-acid battery?
Why not leave its contacts attached?

I wouldn't want to store my car outside in the sun for 3 months. The average temp of the traction battery would be higher degrading it faster, and the sun would bleach the paint and the upholstery I'd rather disconnect the 12v battery and keep it in a nice cool dry garage.

Not the question at all.

Did you read?

Do you read?

The car will be inside in a garage for 6 months.

LI battery charged to 50% ish.

The thread says to disconnect the Lead Acid battery and attach it to a trickle charge.


MY QUESTION IS...

Why disconnect the battery?

Why not just leave it connected on a trickle charge?

With an ICE, leaving the trickle on all of the time is fine, because you aren't going to fire up the ICE and it's alternator. But with EV it boils down to having two chargers attached to the 12v at the same time. One being the trickle, and the other being the traction battery. As the charging function from the traction battery kicks in, it may not properly detect the voltage of the accessory battery. By disconnecting it, you isolate in to two systems, each working the way it was designed to.

Suggest charging to 80%
Remove 12 v and place on a trickle charger such as battery tender.

After 4 months I suspect your traction battery will be around 50-60% from natural loss.