jmurtagh13
Active member
I do not keep the car in the garage. We use our garage for projects. It sits in the sun above half the day. The car is white so that probability helps.
Astral said:Hi all, I am interested in your opinion...
A free "fast" DC public charger has been opened recently near my location, it can give up to 18kwh to my 2018 Leaf. What do you think will this negatively affect my battery long term if I use it once per week let's say to top up from 30 to 80%. Approx 1h of charging.
Usually when travelling we are putting stress on a battery discharging fast then charging fast then discharging fast again, but this scenario would not have any such demands, just simple 2min drive to the charger, leave it for 1h and then 2min back home.
I could also use the AC 6.6kw option but it would take 3 times longer to do the same charge. Is it worth it if I plan to keep this car for a long time?
My current SOH is 87%.
Hit the nail on the head.aneesh84 said:But if the ambient temperature is already at 35 degrees, then its another issue.
hornstudio said:Our 2018 40kWh battery was slow charged 1550 times and 8 times fast in 60.000 miles and SOH is 85% and 3 cell pairs are weak.
Pretty much sums up about 75% of the discussions on this Forum for the last 10+ years (with the rest seemingly about 12v battery behavior).Astral said:So far actually it was quite easy to live with a Leaf. 5 months passed, if it had thermal management and CCS charging, it would be a sweet sweet car.
I would just use it whenever you want: when free DC charging was still available at Lidl Belgium. I made sure to make use of it, so I drove through Belgium instead of the Netherlands when going to South Holland.Astral said:Thank you, nevertheless I will try to use it only when necessary.
aneesh84 said:hornstudio said:Our 2018 40kWh battery was slow charged 1550 times and 8 times fast in 60.000 miles and SOH is 85% and 3 cell pairs are weak.
Do you live in a very hot climate? what mV cell difference you see and at what SOH?
Do you charge to 100% or 80%?
SageBrush said:The LEAF pack does not have thermal control, so it is up to the owner to do what they can/choose to do to mitigate pack temperatures excursions.
Pack heating is due to charging, driving, and ambient. The more aggressive the driving or higher rate the charging, the more heat in the pack. OP: you can only manage this issue if you know the pack temperature, and the gauge in the LEAF is not good enough. Get an OBD2 adapter and pay the couple of dollars for TorquePro App. If your charging session ends up with a pack temp of around 75F or less you are in good shape to minimize the rate of long term degradation.
This is summer, so discussion is focused on high temperatures. In cold winter the same problem exists in reverse: it is a bad idea to use 0.5 C-rate charging into a cold pack
You are looking for a magic temperature threshold, but it does not exist. As pack temps climb, degradation accelerates. In the winter as pack temps drop, the degradation accelerates. Do your best to keep the pack in the 50F - 75F range. Here is the most useful and important point: high (or low) pack temps are particularly a problem at SoC over 85% -- ish, and particularly so when the pack stews in those conditions for hours. If you could charge the pack quickly to 90% SoC and then cool off the pack within an hour, you would not have a worry. But you cannot, so try to avoid that behavior.
Oh -- don't sweat a hot pack day here or there. If it is most days -- not so great.
It is possible to 'manage' pack temperature so long as your climate is not too extreme, but it can be annoying. Do yourself a favor and next time you buy a car, get an EV with thermal control.
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The underlying arithmetic:
18 kW charging dumps 4x the heat into the pack as 9 kW
36 kW charging dumps 16x the heat into the pack as 9 kW
... the relationship is quadratic
My local climate has 90 - 100F daily temperatures for about two months a year. Lucky for us though, the car lives outside in the shade and nights are cooler so the pack tends to hang out at the average of peak and nadir daily temperatures when not driven, and some 5 - 10F degrees hotter depending on daily driving.aneesh84 said:Very well said. However 75 Farenheit (24 degree celcius) is quite impractical since my ambient temperatures are higher than that during the day most of the summer.
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