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Hello, I received a new Nissan LEAF SVE (equivalent to Tekna) in Ireland in April this year and for several months have been very happy with it. However, in September after ca. 7500 km (less than 5000 miles) the battery performance seemed to drop off significantly. Up to that point I had averaged between 1.4-1.5km per 1% of battery charge. Now I’m averaging only 1km per 1%. I still have 12 bars on the display despite an apparent drop in performance of over 30%. I travel the same round trip of 56km every day. This trip used to use max 40% of the battery, now it uses 55%. The board computer indicates that the energy efficiency hasn’t changed much since I got the car, still averaging 14-15kWh per 100km. This indicated to me that the battery appears to have lost capacity rather than any other external factor such as weather or driving conditions. I drive very conservatively, always in eco mode, never over 80km/h (50mph) and have used the rapid charger only 3 times in total, charging each time to 80%. Can anyone explain the reason for the apparent deterioration in battery performance? Why is the display still showing 12 bars? Can the telemetry in the car be trusted? Can I expect any satisfactory explanation from the Nissan dealer? Any information/advice appreciated. Thanks.
 

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There may be nothing wrong.

This may be your problem...
I drive very conservatively, always in eco mode, never over 80km/h (50mph) and have used the rapid charger only 3 times in total, charging each time to 80%.
The Leaf battery does show a decrease in capacity if you never rapid charge. Also only ever charging to 80% means that it never gets to balance the cells which is only done when you to a 100% charge.

Before you take any other action over this I would do a couple of things first:
  • when you next charge overnight make sure you charge to 100%
  • do a few rapid charges... ideally all on the same day. They don't have to be to 100%, in fact I recommend only rapid charging to 80%, but the rapid charging seems to reset the battery management system and you may find your battery capacitty return to nearly new levels.
  • give it a bit of a blast now and then (within the speed limits of course) to push the battery a bit. It wouldn't be good all the time to stress the battery but in my experience it does help to do it now and then... and it is fun!
I would do a 100% charge at least once a month (I do 2 or 3) and I would also try to have a day a month when you do at least 1, but I try to do more than one, rapid charge to 80% on the same day.

Let us know how you get on :)

Regarding your other questions:
Why is the display still showing 12 bars?
You will not lose the first bar until your car has lost about 15% capacity. That usually doesn't happen in the UK/Ireland until about 3 years or 30,000 miles ish. It can happen earlier or a lot later. Some Leafs in Cornwall are on 100,000 miles and only ever rapid charge.

Can the telemetry in the car be trusted?
Not completely no.

Can I expect any satisfactory explanation from the Nissan dealer?
Depends on the dealer but probably not. I don't know any dealer myself that would be able to help much with this... not even the good ones!
 

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You can have 12 bars but still lose some range and capacity. In the early years of the battery life this is usually recoverable to some extent but later on it might not be.

It doesn't hurt to give it a good charge on the rapid chargers. Don't be afraid of them, it doesn't damage the battery especially the Gen2 models. The batteries need to be charged to 100% at times as well to allow the car chance to do some balancing of the individual cell voltages.

As a start try charging up overnight to 100% and leaving it like that for a few hours which should allow some balancing to take place. At some point take it to a rapid and charge it up good and proper which anecdotally can also kick some life into the battery. There are some threads on here about that and several people have seen range improve after a period of high charging and balancing.

Do you have Leafspy? If you get the Leafspy app and an ODBII wifi adapter you can snoop on the car systems and see all the cell voltages, so you can tell if they are out of balance. It also gives indications of the battery state of health and range etc so you can see if there's any noticeable deterioration.It's a bit nerdy but for a small investment you get an excellent stethoscope into your Leaf - you can always post the readings here and people will help ou interpret them.
 

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As an example... last weekend I started out with my battery capacity at about 60Ah. I drove 800+ miles over 3 days rapid charging all the way and when I returned my capacity was back up to 67Ah... a 10% increase :)

Without rapid charging I would expect that to drop back down again within a week or two.
 

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Cooler weather will affect the efficiency big time. With the last day or so being quite cool, I only got an average of 3.6 mi/kWh. Since the cooler weather has come I no longer am getting 1mile per 1%. Closer to 0.75 mile per 1%.
 

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As an example... last weekend I started out with my battery capacity at about 60Ah. I drove 800+ miles over 3 days rapid charging all the way and when I returned my capacity was back up to 67Ah... a 10% increase :)

Without rapid charging I would expect that to drop back down again within a week or two.
But after a day or two it will be back down to 60Ah. Mine never seems to stay up. It goes back down again.
 

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Discussion Starter #8
Thanks a lot for the replies. I will definitely give the rapid charging a go. (Though here in Ireland that's about to become a very expensive habit!). I should check out the Leafspy option too.
Cooler weather will affect the efficiency big time. With the last day or so being quite cool, I only got an average of 3.6 mi/kWh. Since the cooler weather has come I no longer am getting 1mile per 1%. Closer to 0.75 mile per 1%.
I don't think it's this - in my case the efficiency hasn't changed, just the battery's useable capacity. Also the weather was still very mild when I first noticed the change.
 

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And I risk sounding pedantic but when you let the car charge to 100%, leave it plugged in and switched on for about 3-4 hours after as this balances the cells.

I know others mentioned this but didn't fully clarify leaving it plugged in and switched on.
 

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And I risk sounding pedantic but when you let the car charge to 100%, leave it plugged in and switched on for about 3-4 hours after as this balances the cells.

I know others mentioned this but didn't fully clarify leaving it plugged in and switched on.
Hi, can you clarify what you mean by switched on?

Do you mean full ignition on, then just close the car and walk away (with the key on your person). ?
 

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when you let the car charge to 100%, leave it plugged in and switched on for about 3-4 hours after as this balances the cells.
Where have you seen that? If you look at the charging profile with LeafSpy then it looks like the balancing all takes place at the end of the charging cycle. By the time the lights go out the cells are balanced. It just extends the charging time and when the lights go out so it is charged and balanced. AFAIK if you leave it plugged in until the blue lights go out then it is balanced.

If I am wrong perhaps someone might point me in the direction of somewhere to confirm it. Thanks.
 

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When I've watched LeafSpy it seems to do the balancing at the end of the cycle after the charge. Maybe LeafSpy only runs when the car is still plugged into the mains, or maybe the balancing only occurs when still connected to the mains despite the 3 dash lights switching off.

It does seem to balance them with the 3 dash lights flashing, but also afterwards. Isn't that why it's bad to keep the car at 100% and plugged in for long periods?

I too could be wrong and only followed instructions which I'm sure I either got from this forum or mynissanleaf when investigating LeafSpy.
 

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It is bad to keep the battery at 100% because Lithium Ion batteries don't like it. No Li-Ion battery like it. If you are keeping the car unused for a while it is best kept at 45-50%. Any appreciable time spent at 100% or at below 20% can shorten its life.

I am not sure that keeping it plugged in matters much. Once the charge has finished, AFAIK, it doesn't charge again until the next time on the schedule or when you start it manually. Then yes, if you leave it plugged in and it starts charging again, with the charge already up at 80% or over, then it can reduce the battery life. That is why Nissan don't warranty damage caused by charging when it is already over 80%.

So, it doesn't matter if you leave it plugged in after a charge providing you unplug and use it to get SOC below 80% before plugging in again.

It is worth noting that this instruction not to start a charge when over 80% precludes a double charge at a rapid to get nearer 100%. I never start any charge, rapid or slow, if the car is up at 80% or more. Of course... sometimes we may not have a choice and I guess that is a risk we take but I'd suggest not to do it too often.

I would like to find the provenance of it balancing after the charge has finished because from what I have seen, or remember to have seen (may be remembering wrong!), the balancing all takes place at the end but with the lights on while it is still charging. If I am wrong then fine but either way it would be good to know :)
 

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Keeping it at 100% for a few hours before you use the car again isn't going to hurt it, only if you store it for extended periods like many days or weeks. This is not the case here.

I also understood the car did the balancing at the end but whether or not that's before or after all the blue LEDS go out I don't know. In practical terms it mostly doesn't matter for us since in normal use the charging finishes about an hour before the car is used and it stays plugged in. Might look at it with Leafspy one day when I have time and see what the sequence of events is.

This has reminded me, though, that we've not been on a rapid for a while so probably time for a wee road trip again :)
 

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Keeping it at 100% for a few hours before you use the car again isn't going to hurt it, only if you store it for extended periods like many days or weeks. This is not the case here.

I also understood the car did the balancing at the end but whether or not that's before or after all the blue LEDS gonout I don't know. In practical terms it mostly doesn't matter for us since in normal use the charging finishes about an hour before e car is used and it stays pkugged in. Might look at it with Leafspy one day when I have time and see what the sequence of events is.

This has reminded me, though, that we've not been on a rapid for a while so probably time for a wee road trip again :)
Shrewsbury rapid nearly ready if up this way again....;)
 

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Ooh likey likey! Yes, Portmeirion booked again just after Christmas until the New Year! Not sure what the trip would be like in the Leaf in mid-winter though, if it's dodgy it might be the 4WD diesel stinkpot - although might sit there ICEing the rapid just to savour a virtual EV experience :D
 
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Off-topic: @Steve Thayne where is the Shrewsbury rapid? Is it in town or on the A5/bypass?
 
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