Just purchased 2012 gen1 leaf, need advice on battery readings please.

Hi all,

Located in the UK, I have just purchased a 2012 gen 1 leaf that has covered 23000 miles.

I hav got a leafspy and plugged it in to see what was happening during the charge process, the car charger is cutting off at 90% state of charge, no timers are set.
The battery voltage on cut off was 393v, most cells were at 4.1v at this time, Minv was 4.085v maxv was 4.104v (19mv apart).

Bat stats Ahrs 57.95
Soh 88%
90% state of charge
82.9% gid (233)
18.1kwh
52.21 Ah

I don't know if the car should be charging to 100%, or stay close to that level to balance the cells, is there a way to force charge to 100% to enable a balance function, I do have 1 cell that was low all the way through the charge sequence.

Should I pump a few rapid charges into it to jiggle the cells up abit?

Any help greatly appreciated with this observation.

Thank you.

Truthfully I'd love to have numbers like yours, my '12 came from southern CA and is a fair amount worse than yours. At first mine refused to charge much up over the upper 80s SOC, then it would stop. After doing a couple full charge(well to upper 80s) and deep discharges(to VLB or even turtle once) it now regularly charges up to the lower 90s. Now I'm not sure if I've actually gained range/battery capacity, as I didn't have a way to measure capacity until after I did my deep cycles but it's just nice seeing it start off at the lower 90s vs upper 80s, even if I haven't actually gained any capacity
BTW on my most recent full charge my readings were, missing 2 bars:
SOH 58.84
SOC-92.94%
GID%-75.11(211)
Ah-50.9

Not sure about using the fast charge to balance cells, I always thought a slower charge was better for that....

Update, my SOH according to LeafSpy is 77%, NOT 58.84, the 58.84 was actually the Hx%

Soh 88% is all you need to see. Way better than my 77% SOH.

Quickcharge can help the numbers temporarily but doesn't do any long term change good or bad.

Slow charge to 100% and staying plugged in can balance but isn't needed really if you are seeing 19mv spread.

Drive and enjoy.

If yo want to worry about something keep a keen eye on your tire pressure. You have much more control on it and it will actually affect your range noticeably. I run very near sidewall max on mine year round (adjusting the tire pressures several times a year based on min temps I see per season).

Thanks for those replies,

On page 1 of leafspy where the cells are displayed in line, the ah states 57.8Ah, but during charge only 52Ah are being stored in the battery, albeit at 90% state of charge when my charger cuts off.

Should I plug in the granny charger 240v 8 amp charger, and leave it on overnight, or, run the car to vlbw then charge up slowly using the granny type brick charger to see if anything Improves.

I am showing 12 bars at the moment though. At what point in time do bars start to disappear, if I'm at 88% soh now, when does the loss of bars process begin, and foul goby what soh is the battery at when a warranty claim can be made?

Thanks again.

Anthony.

Glyndwr1998 said:

Thanks for those replies,

On page 1 of leafspy where the cells are displayed in line, the ah states 57.8Ah, but during charge only 52Ah are being stored in the battery, albeit at 90% state of charge when my charger cuts off.

Should I plug in the granny charger 240v 8 amp charger, and leave it on overnight, or, run the car to vlbw then charge up slowly using the granny type brick charger to see if anything Improves.

I am showing 12 bars at the moment though. At what point in time do bars start to disappear, if I'm at 88% soh now, when does the loss of bars process begin, and foul goby what soh is the battery at when a warranty claim can be made?

Thanks again.

Anthony.

Click to expand...

screen 1 is the only one that shows absolutes, the data on screen 4 or 3 is relative, don't worry about that data.

SOH% will be in the mid 80s when you lose the first bar, think 85%.

SOH hits about 65% at 4 bars lost, most here pay attention to AHr as it's finer grain but I do like watching SOH% because it's easy to do math in my head with a number that is normalized to 100% scale.

as to what to do, if you are in the UK and aren't taking the ferry or tunnel and driving to southern France or Spain or other warmer parts of Europe, I wouldn't bother the pack will take care of itself. Don't leave it charged to full more than a few minutes or an hour or two if you can help it, don't take it down to VLBW or Turtle unless you need to for a rare emergency.

Keep your tire pressure up near sidewall max if you don't mind a harsh ride. Keeping your tire pressure up is probably more important that your charging habits in a mild or cold climate.

You don't need to balance your pack often but when you do decide to do it schedule it with heat and time spent at full in mind

* Time spent at full in the heat is bad
* Time spent at full charging does the balancing
* Do you balancing in winter to offset those needs
* Or be ready to drive away very very soon after the charge hits full if it isn't winter.

It's not ultra critical for you in a northern climate but as a general rule I don't charge to 100% if it is short sleeve weather and I really don't worry about it much until its below freezing outside unless I have a long trip forcing the issue.

Otherwise I charge to 50% or 60% or 70% or 80% as I need. Nothing exact, just charge it somewhere above what I need.

Pack balancing works best at low amp charge rates.

High amps save you money on your electric bill.

So 99% of the time you should pick the charge rate that saves money and save special actions to balance the pack for rare occasions.

Thanks for the replies and advice.

My initial concerns were the state of charge and state of health.

Ok the car has done 23000 miles so I'd expect wear on the battery, it's learning to what is acceptable wear or extreme wear,

Also, I'd also expect the car to charge to 100% if it's set to do so, so I can't get my head around why leafspy
is reporting state of charge of 90%, and why the car stops charge at 90%,

For instance if the battery has a state of health of 88%, I'd still expect the car to charge to 100% of the 88% that's left and available.
So for instance, for easier numbers, lest say the range at 100% state of charge when new was 100 miles, the car has now a state of health of 88% so at a state of charge of 100% I'd expect a range of 88 miles, not 90% of 88 miles, if that makes sense.
Whatever the state of health is, if needed I'd expect the car to charge to 100%, I can set the charge level myself if required via timer or % charge level, I just can't get my head around why the car is stoping the charge at90%.

I'm reassured that as we have a colder climate here in the UK the battery lasts longer, so that's good, very good, I just want to understand the figures, why it's happening and monitor regularly for any sudden changes.

Thanks again for your help with this.

Anthony.

Leafspy shows you the data from the internal computer like what Nissan would see from the telematics and diagnostic reports.

The dash shows you massaged data to meet uninformed customers expectations.

The reality behind that isn't neat even or round numbers.

A full charge is called 100% on the dash but varies internally and on leafspy. It could be 92.7% one day and 95.4% another. Its based on how much energy was stored in the pack when charging stopped but charging stops not based on energy stored but because one or more cell pairs hit the maximum voltage or a temperature limit was reached. You'll see a different max charge in the heat vs cold, a different max charge when charging at low amps vs high. It isn't terribly significant what the end of charge percentage said.

SOH% has nothing to do with determining what SOC% is at full charge but conceptual they combine by way of multiplication to be representative of the total amount of energy stored. The actual amount of energy stored is in kWh but you can think of SOC% as related to what percent of kWh is in the pack currently and SOH% as related to how much lower the kWh max is compared to a new battery.

With a leaf miles pretty much don't matter, I'll leave you with my quote from another thread about what causes degradation for a Leaf battery pack.

1 Heat (ambient temp)
2 Heat (driving or charging)
3 Heat - because Nissan uses passive cooling the heat will remain for 10-20 hours after being generated or absorbed
4 Age
5 Heat - just making sure you saw this
6 any thing else

seriously you don't need to worry about speed of charging, number of charge cycles, or miles driven. Just pay attention to heat and age.

Click to expand...

hi dhanson865,

Thanks for the replies.

Since i have been driving the leaf over the last 2 weeks i havent seen the battery temp guage get higher than 4 bars, the ambient here in the UK at the moment is around 8c, we are quite a cold climate com,pared to many others, and I have read that heat has a bad effect on battery health and performance.

After the charge which was cut off by the car at 90%, most of the cells are sitting at around the 4.08v area, the highest is 4.095v, quit a conservative cut off, with being on various ev forums and self build EV forums, cutting off at 4.1 with a full blown auto balancing bms like the leaf has is very conservative.

I did see one pair of cells alittle higher before the charger cut off event, nothing significant though, wondering when the bms actually addresses these high cell pairs to bring them back in line alittle.

I have used a leaf battery in project build myself installing a 16kwh leaf pack into a prius converting it to a plug in hybrid, and i used even tighter tolerenace, i charged to 4.05v and discharged to 3.6v, using only about 70% of available capacity.

My brother has a 2014 leaf too and i drove that for about 6 weeks whilst he was having his evse charge pint fitted, and it seems his gen2 is much healthier than my 2012 leaf.

I`ll do a test this week to see the actual miles covered per charge, it does seem though that the firts 3 charge bars go quite quickly, within 15 miles, i didnt se this reductiuon in the gen2 leaf of my brothers, maybe his firmware is better and more accurate than the one in the gen1 leafs, the regen on his for sure is way more aggressive.

Many thanks,
Anthony.

Glyndwr1998 said:

it does seem though that the firts 3 charge bars go quite quickly, within 15 miles

Click to expand...

Since you have lost 12% battery capacity, and each bar represents about 8% charge, that means that each bar is now worth about 1.66 kWh of capacity, and 3 bars would be about 5 kWh. If you only got 15 miles out of 3 bars, that would be 3 miles/kWh, which might be right if you are running the heater and/or driving fast. I tend to average better than 4 miles/kWh. I would reset the energy use graph and compare. The more the battery degrades, the faster the charge bars drop. Also, once you get close to 85% capacity, the 12th charge bar tends not to always show with a full charge, or disappear quickly after you start driving. More faulty Nissan instrumentation. That is why we always recommend getting our data from LeafSpy instead.

Thanks Keydiver,

I will need to give the car a good drive to see how many miles its now capable of per 100% of the remaining capacity.

Id still like to see the car to charge to 100% though if and when required, not stop at 90%. It deoesnt mean alot i know as id probably charge t 80% anyway, but i would like to test what mileage is available at 100% soc and test periodically to verify and record the degradation of the battery.

Also, as indicated to earlier, stay away form any heat, i know from electronics, heat is a big issue with premature ageing.

Many thanks,

Anthony.

dhanson865 said:

1 Heat (ambient temp)
2 Heat (driving or charging)
3 Heat - because Nissan uses passive cooling the heat will remain for 10-20 hours after being generated or absorbed
4 Age
5 Heat - just making sure you saw this
6 any thing else

seriously you don't need to worry about speed of charging, number of charge cycles, or miles driven. Just pay attention to heat and age.

Click to expand...

[/quote]

In a cool climate, miles (aka battery cycles) matter relatively more. In case you have not seen this:

http://www.electricvehiclewiki.com/Battery_Capacity_Loss

If your city/climate has an aging factor over 1, heat then time are the keys.

If your city/climate is close to 0.6, and you are driving (US average) 12,000 miles (20,000 km) a year or so, the mileage loss would be greater than calendar loss, according to the battery loss model (about 60%:40%). If you drive half of that, the two losses would be nearly equal. Heat and time are what determines calendar loss.

WetEV said:

dhanson865 said:

1 Heat (ambient temp)
2 Heat (driving or charging)
3 Heat - because Nissan uses passive cooling the heat will remain for 10-20 hours after being generated or absorbed
4 Age
5 Heat - just making sure you saw this
6 any thing else

seriously you don't need to worry about speed of charging, number of charge cycles, or miles driven. Just pay attention to heat and age.

Click to expand...

In a cool climate, miles (aka battery cycles) matter relatively more. In case you have not seen this:

http://www.electricvehiclewiki.com/Battery_Capacity_Loss

If your city/climate has an aging factor over 1, heat then time are the keys.

If your city/climate is close to 0.6, and you are driving (US average) 12,000 miles (20,000 km) a year or so, the mileage loss would be greater than calendar loss, according to the battery loss model (about 60%:40%). If you drive half of that, the two losses would be nearly equal. Heat and time are what determines calendar loss.

Click to expand...

Stoaty, JP White, Surfing Slovak all did great work on the degradation model but the 1.0 value is based on Los Angeles climate and Nissan's claims about degradation.

I think if you look through these forums and / or the bar loss wiki data you'll see that charging cycles/mileage are heavily swamped out by Heat/Time.

I stand by my prior post on the subject. Feel free to go to the model thread and do the numbers there if you want to continue this discussion to the next level of detail.

Notice that the battery aging model thread started in 2012 before we had long term data and ended with a last post in spring 2013. Since then the battery loss wiki has more entries than I care to count and most of us that bother to update the wiki only do so for exceptional reasons.

Relying on projections from 2012 when we have newer data that we know contradicts the old model in a large number of cases isn't what I'd recommend.

dhanson865 said:

Stoaty, JP White, Surfing Slovak all did great work on the degradation model but the 1.0 value is based on Los Angeles climate and Nissan's claims about degradation.

Click to expand...

And the model was updated to more closely match experience.

It would be interesting to do another round of data collection, and see how close the model is tracking. Would be most interesting to get some cool climate Leaf data.

There is one cool climate Leaf that has lost 5 bars at 141,000 miles. http://www.mynissanleaf.com/viewtopic.php?f=31&t=20275#p431911


I'm not aware of any other cool climate Leafs that have lost more than 2. Warm climate, sure. Hot climates? Oh yea.

While the model is wrong, as all models are, I suspect that it is still useful.