The 62kWh Battery Topic

[LeftieBiker]

There is a section of connecting highway near here where you have a 65MPH road going down a steep hill for almost two miles. I was able to get not just top speed, but more than top speed, from my '86 Civic Si. Not many of those cars have done 125MPH box stock.

[DougWantsALeaf]

Question for the board. How bad do we think cool temp DC charging is for the battery?

This morning I charged (still enjoying my nctc for both Leafs) from 39% to 79% during a 1/2 hour charge. The battery temp went from 68F to 85F. It was 38F this morning, so temp starting dropping again as soon as I unplugged, and after the 8 mile freeway drive back home was already down to 83F. This was our SV+.

Do we think that these short sessions hurt the battery more than a long level 2 charge for same charge?

[WetEV]

Question for the board. How bad do we think cool temp DC charging is for the battery?

This morning I charged (still enjoying my nctc for both Leafs) from 39% to 79% during a 1/2 hour charge. The battery temp went from 68F to 85F. It was 38F this morning, so temp starting dropping again as soon as I unplugged, and after the 8 mile freeway drive back home was already down to 83F. This was our SV+.

Do we think that these short sessions hurt the battery more than a long level 2 charge for same charge?

Cool temperature DCQC might be worse than warm temperature DCQC. Issue is Li plating.

[DaveinOlyWA]

Question for the board. How bad do we think cool temp DC charging is for the battery?

This morning I charged (still enjoying my nctc for both Leafs) from 39% to 79% during a 1/2 hour charge. The battery temp went from 68F to 85F. It was 38F this morning, so temp starting dropping again as soon as I unplugged, and after the 8 mile freeway drive back home was already down to 83F. This was our SV+.

Do we think that these short sessions hurt the battery more than a long level 2 charge for same charge?

Hard to say since Nissan isn't very open about their chemistry's characteristics. I venture to say probably not but there is growing evidence that higher SOC is worse no matter how you got there. You are parking the car @ 75% which I think is worse for the long haul.

The biggest reason I got a larger pack is having the ability to do a greater range of experiments and the one I am currently running is centered around leaving SOC below 50% nearly all the time which I have done quite easily over the past few months. Granted, part of it was several canceled events making any trips out of town quite rare.

Like any experiment, the longer it runs the better the data. So we should know something by TG or so?

[DougWantsALeaf]

I can make keeping car under 80% work for all non-trip travel. I am not going to sweat whether car is kept under 60% all the time or not.

Our 2013 Leaf even at 11 bars really met most of our car needs, so not worrying to much about the Pluses being sufficient. Boy with the deals you can get now, maybe I should have waited a year on the first car (though i have enjoyed it in that year).

Chargepoint DC stations seem to be moving at warp speed now. The map is filling in quickly.

[SageBrush]

Question for the board. How bad do we think cool temp DC charging is for the battery?

This morning I charged (still enjoying my nctc for both Leafs) from 39% to 79% during a 1/2 hour charge. The battery temp went from 68F to 85F. It was 38F this morning, so temp starting dropping again as soon as I unplugged, and after the 8 mile freeway drive back home was already down to 83F. This was our SV+.

Do we think that these short sessions hurt the battery more than a long level 2 charge for same charge?

I would not worry at all about the sort of session you had today but as winter progresses the battery will be too cold to take high currents without Li battery plating.

I know you are still in high SoC/high-temp mode but without a TMS a cold battery and DCFC are also a bad combination. You will have to look up the temps where 50 - 70 kW charging (125 - 200 Amps) becomes a problem.

I've said it before, and here it is again: It is penny wise and pound foolish to DCFC just because it is 'free.' Reserve its use for when you are on trips and your battery will thank you.

[DaveinOlyWA]

I can make keeping car under 80% work for all non-trip travel. I am not going to sweat whether car is kept under 60% all the time or not.

Our 2013 Leaf even at 11 bars really met most of our car needs, so not worrying to much about the Pluses being sufficient. Boy with the deals you can get now, maybe I should have waited a year on the first car (though i have enjoyed it in that year).

Chargepoint DC stations seem to be moving at warp speed now. The map is filling in quickly.

Well, its your comfort zone you need to manage. For me, there are simply too many public charging options around to get into any real trouble no matter what level I choose to maintain.

I guess the real question becomes "how cold is too cold?" I doubt 68º or even anything in the 50's is much of an issue but really clueless here. Bolts throttle charging at very moderate temps like the 50's. Granted OAT and batt temps are generally not similar especially if you park in the garage. Even winter days when my car was gone from home 18 plus hours (too common at my previous job) the batt temps still stayed well above ambient.

When I was first aware of Bolt throttling issues, I kept my car outside overnight (just one time and I felt bad for weeks afterward. The look on her face when I closed the garage door for the night will haunt me forever) and batts hit the mid 40's (overnight low was high teens low 20's) which was only 5-9º lower than normal when left in the garage. So they cool somewhat rapidly to a point then slow way down.

I guess like overheating, its an issue in places but just not here.

[DougWantsALeaf]

Yeah only time wi tell with these batteries.

Ok, I didnt pay attention to this last year, but ir looks like before Nissan released the 62 batteries, they were considering a 64kWh battery.

https://iaspub.epa.gov/otaqpub/display_ ... 723&flag=1

A few weeks later they tested this one.

https://iaspub.epa.gov/otaqpub/display_ ... 724&flag=1

I wonder if it a voltage change or physically a different battery once they knew they had 200 miles in the bag.

[DaveinOlyWA]

Yeah only time wi tell with these batteries.

Ok, I didnt pay attention to this last year, but ir looks like before Nissan released the 62 batteries, they were considering a 64kWh battery.

https://iaspub.epa.gov/otaqpub/display_ ... 723&flag=1

A few weeks later they tested this one.

https://iaspub.epa.gov/otaqpub/display_ ... 724&flag=1

I wonder if it a voltage change or physically a different battery once they knew they had 200 miles in the bag.

hard to read on phone but didn't see 64 kwh designation anywhere. I did see a recharge event of 68.something kwh though which implies just under 62 kwh usable. That would be "about" 64 kwh pack.

[DougWantsALeaf]

The earlier recharge was to 70kWh and the later 68kWh. Assuming about a 10% loss for both.