2013 Battery balancing

[siai]

I recently traded my 2012 LEAF for a 2013 to get the better heater and the 6.6 KW charger. I have a question about the charging sequence. When I charge to 80%, it doesn't take long to get there and if I watch the battery % of charge on the dash it charges at full power right up to 79 to 80% and then shuts down. When I charge to 100%, the charger runs at full power up to 98% and then goes to a very low power setting which may take an additional 40 to 60 minutes to reach 100%. I assume the battery is balancing at this point, however it seems like it taking a long time to do this. I never noticed this on my 2012 and the driving range on the 2013 seems to be in the ballpark. Has anyone else noticed this or is it something I should mention to the dealer?

 

[RegGuheert]

When I charge to 100%, the charger runs at full power up to 98% and then goes to a very low power setting which may take an additional 40 to 60 minutes to reach 100%. I assume the battery is balancing at this point, however it seems like it taking a long time to do this.

While I cannot answer your questions, I will say that this sounds like a much better algorithm than what is included in the 2011/2012s. This should be capable of fully balancing the cells with a single charge to 100%, which is something the older LEAFs did not seem able to do with the exception of L1 charging. The benefit here is that you can be assured that you are leaving with a full and balance pack, something I am never quite confident of unless I charge our 2011 at L1.

 

[Petecomp1]

My '13 SV is exactly the same. Very quick to 80% (sometimes 79%) but 3 more hours to reach 100%. I do know that the charge tapers off as battery voltage reaches maximum, but I don't know anything about balancing cells. More info would be useful -- anyone?

 

[LeftieBiker]

It may not be so much balancing the cells as just tapering the charge to avoid damaging them. Pretty much all battery chemistries benefit from a "bulk charge" to 80% or so, followed by a reduced rate to 100%. Quick charging to 100% is convenient, but not necessarily good for the pack.

 

[JasonA]

If you are talking about L3 or DCQC'ing then no, there is really no time for good balancing... But on 11 & 12's with the new FW/program update, the charger does taper off at or near 98% and throttle down to balance to top off the cells.

This is apparent if you have one of the devices like LeafDD, Canary, etc..

My 2012 never really did it before the update. As far as fast charging goes, L2/6.6kw (not really on a 2013 even).. it's not even 1/4c charge rate for the pack after losses, etc..

I'm shoving in 7.2kw+ (18amps) and that's hardly 1/4c rate. The pack only feels the burn on CHAdeMO.. LOLOLOL..

100+ amps into the pack!!

 

[Stanton]

If you are talking about L3 or DCQC'ing then no, there is really no time for good balancing... But on 11 & 12's with the new FW/program update, the charger does taper off at or near 98% and throttle down to balance to top off the cells.

This makes sense now that I'm getting more 10 bars @80% charges since the P3227 update. At first I just attributed it to the BMS "relearning" the pack, but after a month I'm more inclined to think that I get less premature charge terminations (ending @9 bars) since the charge "velocity" is slowing down. That doesn't mean that I ALWAYS get 10 bar charges (I still see some 9's on really hot nights), or that I won't see the 9 bars @80% trend again as I near another bar loss, but I'm still seeing my first 10 bars @80% charges in a long time.

 

[JeremyW]

The pack only feels the burn on CHAdeMO..

And that's my pack you see burning there. Went from about 24c in the morning to 38 or 39c when I got home, with two quick charges spaced about 5 hours apart. :? But hey it made the 140 mile journey at 65-75 mph speeds without issue.

 

[DaveEV]

If you are talking about L3 or DCQC'ing then no, there is really no time for good balancing... But on 11 & 12's with the new FW/program update, the charger does taper off at or near 98% and throttle down to balance to top off the cells.

This makes sense now that I'm getting more 10 bars @80% charges since the P3227 update. At first I just attributed it to the BMS "relearning" the pack, but after a month I'm more inclined to think that I get less premature charge terminations (ending @9 bars) since the charge "velocity" is slowing down.

I believe that you are seeing more 10 bar 80% charges simply because the Ah reading is higher post update for you.

I have had solid 9 bar 80% charges for the last month or so now - I saw a few last year at the end of Summer, but hadn't seen any yet this year until a few weeks after the P3227 update and Ah readings settled back down.

Also, I'm not seeing any extended time to charge to 100% post P3227 - I still see about 15-20 minutes from when the car starts tapering off the charge to charge completion as recorded by my Blink EVSE.

Wish it were true - I have a stubbornly low cell-pair that is typically around 6-7 mV below the next lowest cell-pair and about 20 mV below the average.

 

[Rauv]

deleted.

 

[GregH]

It may not be so much balancing the cells as just tapering the charge to avoid damaging them. Pretty much all battery chemistries benefit from a "bulk charge" to 80% or so, followed by a reduced rate to 100%. Quick charging to 100% is convenient, but not necessarily good for the pack.

Yes. I saw this when I had the 2013 loaner. The 2011/12s taper pretty quick and terminate soon after. The 2013 has a long taper and even at <1.0A can hover for 20-40 minutes. While it may be balancing here, the main purpose is probably to squeeze a few last electrons in without exceeding a cell voltage (I saw 4.123V max). Once a decision on balancing is made, the balancing can happen any time the car is on or charging regardless of the SOC. I think the new integrated OBC on 2013 has much finer current control during charge than the 2011/12 OBC which seemed to be in steps of 1.0A.

 

[voganni]

My 2013 behaves the same on 100% charging. Another thing I've noticed is the AV charging dock "vehicle charging" light starts flashing during this final phase of charge. A few times I've been in a hurry and didn't wait for the balancing part to finish, just stopped the charge and left. Range was still the same, and 100% SOC showing on the dash display. My wife and I love the Leaf! If the 2015's really can hit the 150 mi. range point, they won't be able to build them fast enough! And that's when my current lease ends............

 

[Rauv]

I have graphed "wall" watts versus time for my 2013 Leaf with 60 Ah battery, and it shows the charge tapering near 100% and then a rebalance. Now that I have an ELM and LBA, I will try to re-graph pack differentials voltages during the rebalance period. Maybe someone has already done that.

edit. deleted graph. having more problems posting.

 

[Graffi]

It really would be nice is NISSAN could put out a "Best Practices" list so those of us new to the EV arena can learn how to best protect our battery. I am learning a lot by reading this forum, but there is just soooooooooo much out there and in lots of threads. It is very exciting learning about all these things, but would be helpful if I did not learn it "too late" because it was buried in a non-related thread.

Thanks everyone.

 

[GregH]

It really would be nice is NISSAN could put out a "Best Practices" list so those of us new to the EV arena can learn how to best protect our battery. I am learning a lot by reading this forum, but there is just soooooooooo much out there and in lots of threads. It is very exciting learning about all these things, but would be helpful if I did not learn it "too late" because it was buried in a non-related thread.

Thanks everyone.

The problem is there is no single answer..
Batteries will last longer if they are cooler.
Batteries will perform better if they are warmer.
(Lithium) Batteries will last longer if they are at a lower voltage/SOC.
Batteries are obviously more convenient if they have more charge when you need it..

 

[joewaters]

Not really sure if this fits the topic, but can't see it being far off-topic. My 2013 SL, when set with end timer, always stops charging with 40 minutes remaining til full charge on either L1 or L2 EVSE. For reference, I have a Schneider EvLink v2.5 30 amp EVSE on a dedicated 30amp circuit breaker on the (separate) garage 100 amp Breaker box, though I almost know the issue is with the car since it did the same with the Panasonic Brick before the L2 was installed. I wonder if this is due to the cell balancing or accuracy of the charging timer? I did get my update notice yesterday, so maybe the Leaf tech will be able to answer this. But I am wondering if anyone else with a 13 had noticed the same thing.

 

[TomT]

The 2011 and 2012 do the same thing... It appears to be simple inaccuracy in the timer...

But I am wondering if anyone else with a 13 had noticed the same thing.

 

[joewaters]

Thank you ,Tom.
I searched for it but found no info in the wiki or forum posts, save this one. It is not of any real concern, since the small amount gained in that last "40" wouldn't be very much. I'll still check with my Leaf tech about it, as I would like the question answered by Nissan in some fashion.
I take it that many Leafers have noticed this and dismissed it out of hand as not worthy of concern.

 

[planet4ever]

Not really sure if this fits the topic, but can't see it being far off-topic. My 2013 SL, when set with end timer, always stops charging with 40 minutes remaining til full charge on either L1 or L2 EVSE.

Your statement confuses me. Are you saying that

• it stops charging 40 minutes before the time you set, regardless of whether the battery is fully charged? Or
• the battery is fully charged 40 minutes before the end time you set? Or
• the "charging Time" display shows 40 minutes more required, even though the car has stopped charging?

(b) is common, and is generally ignored. The other two possibilities sound weird and worth looking into.

Ray

 

[joewaters]

Your statement confuses me. Are you saying that

• it stops charging 40 minutes before the time you set, regardless of whether the battery is fully charged? Or
• the battery is fully charged 40 minutes before the end time you set? Or
• the "charging Time" display shows 40 minutes more required, even though the car has stopped charging?

(b) is common, and is generally ignored. The other two possibilities sound weird and worth looking into.

Ray

Sorry for the confusion, Ray
It is on an end timer, so I imagine, not being present when the charge cycle actually finishes, that it simply falls short of the goal of 100% as the appointed time is reached. The display shows need for the additional time on the 'time to reach full charge'.

 

[planet4ever]

It is on an end timer, so I imagine, not being present when the charge cycle actually finishes, that it simply falls short of the goal of 100% as the appointed time is reached. The display shows need for the additional time on the 'time to reach full charge'.

Possible, but unlikely. Most people find that the calculation is conservative, so charging finishes early. I would suspect that your Power Distribution Module has a problem. See this thread: Bad Power Distribution Module? Check In Here

Even if you haven't seen the dash warning lights discussed there, I suggest you call your dealer or other Nissan service center and find out if Campaign P3259 or NTB13-069 applies to your car.

Ray