Is SOH in Leaf Spy affected by temperature? (Mine seems low)

[marcelg]

I just started using Leaf Spy, and it's showing my SOH at 86%, with 2,459km on it. It had 25km on it when I got it.

My Leaf is a 2017 S (30kwh), which I took possession of in early September, so I've had it for 3.5 months. Charging has been mostly L1 once or twice per week, only getting to 100% a couple of times. I've done one DCFC, from 30% to 57%. Two L2 charges, also not to 100%.

Current temperature here is -3C, but recently it's been averaging between -10 and -20C.
Leaf Spy is showing:
AHr = 68.76
SOH = 86%
363.96V
Hx = 83.60% (what does Hx stand for?)
3QCs & 52 L1/L2s
Temp = 0C
14.56V
SOC=53.9%

On the summary page:
171GIDs 47.9%
SOC-> 53.5% (I was using the heater while trying to figure out how to read Leaf Spy)
13.3kwh remain

Is the SOH affected by temperature? (0C should be a 10% loss of capacity)
Or do I have a dud? (did a dealer leave it parked at 100% too much?)
Or do I need to charge to 100% and then run it to turtle to reset the SOH reading?

Thanks,
Marcel

[LeftieBiker]

These 30kwh packs seem to be Bad News.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=23606

[marcelg]

These 30kwh packs seem to be Bad News.

http://www.mynissanleaf.com/viewtopic.php?f=30&t=23606

Wow, that seems like a really long thread to go through. I started reading it, but didn't find any reference to temperatures affecting the SOH.

If I get a chance, I'll read some more of that thread, but if there's anyone else who knows off hand if the 0C battery temp affects the SOH reading I'd appreciate it.

thanks
marcel

[marcelg]

This thread seems to indicate it is temperature dependent. I'll have to check again a few more times over the winter, and again in the spring when it warms up.

Also, another factor might be that I haven't discharged the battery very much. I usually plug it back in with 50% SOC, and have only taken it below 40% a few times. Once I got down to 19%, but that's the lowest it's been.

[goldbrick]

My story is much like yours. I have a 2017 S that I bought in August. Currently have around 3k miles on it and LeafSpy says SOH = 92%. AHr and Voltage seem to indicate this is the correct reading. It has fallen quite a bit since the summer and I'm wondering if it's the temperature or a bad battery. My commutes are very short so I have no range anxiety and the battery has the 8 year warranty so I'm not that concerned but it is somewhat alarming for a new Leaf owner.

FWIW, my charging habits are very similar to yours. I drove it down to 9% last week and that was the first time I ever encountered the LBW (low battery warning) which came on at 14%.

[LeftieBiker]

The short answer is that the packs do worse in Hot weather, but will still lose capacity rapidly in anything but a cool climate.

[ElectricEddy]

I just started using Leaf Spy, and it's showing my SOH at 86%, with 2,459km on it. It had 25km on it when I got it.

My Leaf is a 2017 S (30kwh), which I took possession of in early September, so I've had it for 3.5 months. Charging has been mostly L1 once or twice per week, only getting to 100% a couple of times. I've done one DCFC, from 30% to 57%. Two L2 charges, also not to 100%.

Current temperature here is -3C, but recently it's been averaging between -10 and -20C.
Leaf Spy is showing:
AHr = 68.76
SOH = 86%
363.96V
Hx = 83.60% (what does Hx stand for?)
3QCs & 52 L1/L2s
Temp = 0C
14.56V
SOC=53.9%

On the summary page:
171GIDs 47.9%
SOC-> 53.5% (I was using the heater while trying to figure out how to read Leaf Spy)
13.3kwh remain

Is the SOH affected by temperature? (0C should be a 10% loss of capacity)
Or do I have a dud? (did a dealer leave it parked at 100% too much?)
Or do I need to charge to 100% and then run it to turtle to reset the SOH reading?

Thanks,
Marcel

Assume the dealer did have it charged close to 100%. The best thing is to check the build date on the drivers door jam. Hopefully it didn't sit too long on the lot (IMPORTANT- in warm weather say above 70 F, which is considered warm north of the 40th where we live.)
When purchasing an EV especially one without temp mgnt like the Leaf it is best to order and p/u same day or next after arrival as the Nissan factory shipping charge level seems to be about 40% for new Leafs.
Don't worry about your stats, your battery pack is probably in hibernation at the last level you left it after the warm weather finished for the year.
Go ahead and charge to 100% when the temp is cold, it should zero affect on the capacity degradation, ( I routinely charge and leave the vehicle at 95% and charge to 100% probably 3 times a week (again this applies only to cold climate conditions), my stats are 76.5 AH, 96% SOH ,91.37% Hx c/w 27.1 kWh 12,000 Kms
Hx is a term given to measure the internal resistance of the pack ( it's conductivity) as a percentage of mho's which all packs have and we Leaf owners try to limit that # and thus reduce degradation.
A good way to keep your capacity as large as possible before winter is to "drive the car" don't baby it before the cold sets in. Also don't routinely drive the car to a low state of charge so below 10% and keep it there for long.
Enjoy

The majority of the degradation seems to happen in warmer climates including south of the border and in Canada during the summer. Try not to leave at a high state of charge during warm weather. I tend to leave my pack at the highest level that will allow max regen during the summer which on my pack is about 90%.

[marcelg]

thanks for the replies. so what you're saying @ElectricEddy is that the SOH reading is affected by the temperature, and the battery's history. Which means that when the temps warm up, the SOH reading might go up again? Basically, the batteries lose capacity when they get cold, and that's what LeafSpy is reading?

If the battery is at 0C, it should be about 10% down, so if it warmed up to 20C, it might come back up to 90%+ SOH?

we did have a warmer than normal November, and then the temps abruptly dropped in December and have mostly stayed quite cold.

[ElectricEddy]

thanks for the replies. so what you're saying @ElectricEddy is that the SOH reading is affected by the temperature, and the battery's history. Which means that when the temps warm up, the SOH reading might go up again? Basically, the batteries lose capacity when they get cold, and that's what LeafSpy is reading?

If the battery is at 0C, it should be about 10% down, so if it warmed up to 20C, it might come back up to 90%+ SOH?

we did have a warmer than normal November, and then the temps abruptly dropped in December and have mostly stayed quite cold.

The capacity will come back and so will the #s to what degree depends on the above.
Leafspy reads what your pack is now
Check your manufacture date

[goldbrick]

Leafspy reads what your pack is now

That answers my question. I guess I was wondering if the BMS or LeafSpy accounted for the temperature of the battery pack and used that to calculate some sort of 'normalized' capacity. Sounds like the answer is no.

I'll try to do some measurements in the future when time allows. We get crazy temperature swings here in CO so it would be easy to do a couple of measurements across a wide temperature swing while the car was sitting. Eg, yesterday the high was 64 here. Tonight's low is supposed to be 13. This kind of swing isn't uncommon in this part of CO during the winter so even allowing for the high thermal mass of the battery pack, it should be possible to see the effect of temperature on the estimated battery capacity.