The 40KWH Battery Topic

[danrjones]

Not bigger but several hundred pounds heavier. Definitely more thermal mass. More mass period. Same surface area.

Correct, which implies a longer thermal time constant to heat/cool.

Which with rapid-gate could mean they needed a fan......... maybe

[DougWantsALeaf]

If they had just build a couple head sinks and a fan into the 62kw design, it would have killed most of the whining about the car battery.

[jlv]

I have heard Teslas at Superchargers that sound like little airplanes with propellers.

I'd describe the noise more like a jet getting ready to take off.

[danrjones]

If they had just build a couple head sinks and a fan into the 62kw design, it would have killed most of the whining about the car battery.

Is that like Torgo's executive powder? A Nissan executive in every Leaf?

[Astros]

FYI; the full rate on "most" chargers around here at 90% SOC would be higher than 44 KW. That is only 366 volts. Do you have a charge curve you can post?

I'm afraid I don't have charge curves. We almost never stay with the car while it's charging, and I've found that LeafSpy loses its connection after a minute or so if the car is turned off. Do you have a trick to keep it recording while you are away?

I was actually surprised to see ~44kW above 90% SoC. With previous Leafs I thought it would only get about half that above 85%. Have I mis-remembered the typical charge taper?

[DaveinOlyWA]

FYI; the full rate on "most" chargers around here at 90% SOC would be higher than 44 KW. That is only 366 volts. Do you have a charge curve you can post?

I'm afraid I don't have charge curves. We almost never stay with the car while it's charging, and I've found that LeafSpy loses its connection after a minute or so if the car is turned off. Do you have a trick to keep it recording while you are away?

I was actually surprised to see ~44kW above 90% SoC. With previous Leafs I thought it would only get about half that above 85%. Have I mis-remembered the typical charge taper?

Plus could be different although I doubt it. The 40 kwh LEAF would be well less than half that rate.

[danrjones]

Looks like i just finished my second big adjustment since i have had the car. As already mentioned I'm not sure these numbers reflect reality. But if they do, my battery is dropping like a rock. I've had the car for about 4 months. We just hit ~ 1500 miles.

Date SOH AMPHr Hx
5/03/2019 97.63 112.70 97.50
5/06/2019 97.62 112.69 97.94
5/07/2019 97.61 112.68 98.03
5/10/2019 97.60 112.67 98.39
5/13/2019 97.59 112.66 98.55
5/15/2019 97.58 112.65 98.73
5/19/2019 97.57 112.63 98.84
5/27/2019 97.55 112.61 99.27
6/01/2019 97.53 112.59 99.61
6/04/2019 97.50 112.55 100.12
6/11/2019 97.44 112.48 101.03
6/12/2019 97.43 112.47 101.25
6/13/2019 97.42 112.46 101.25
6/14/2019 96.49 111.39 101.58
6/15/2019 96.28 111.15 101.58
6/16/2019 95.64 110.41 101.67
6/17/2019 95.42 110.15 101.82
6/19/2019 95.40 110.13 102.15
6/20/2019 95.38 110.11 102.25
7/15/2019 95.19 109.89 103.22
7/24/2019 95.10 109.78 104.04
8/11/2019 94.90 109.55 104.95
8/30/2019 94.73 109.36 106.05
9/05/2019 94.68 109.30 106.27
9/10/2019 94.65 109.26 106.45
9/11/2019 94.64 109.25 106.48
9/12/2019 94.50 109.09 106.47
9/13/2019 93.73 108.20 106.48
9/14/2019 93.30 107.71 106.45
9/15/2019 93.29 107.69 106.45

[danrjones]

I am curious, to anyone / everyone that has a 2018 40, what is the lowest SOH that anyone has?

Mine today is sitting at SOH 93.29%, AHr = 107.69. HX = 106.40%. 17 mV on the Shunting Screen (What is normal for the cell disparity anyway?)

3 QC's (none that I did) and 101 L1/L2 (not sure that is right either)

[LeftieBiker]

I'll know next month, when I do my 6 month LeafSpy check.

[danrjones]

If you plot out my data, the big drop is EXACTLY 3 months apart, just like someone else here said it would be . My next drop should be on Dec 12-14th.

This whole thing sure looks like a computer is controlling the curve rather than simply reporting data. You SOH drops exactly 0.01% every day no matter what, then every 3 months like clockwork it must re-compute / evaluate the data its been collecting. But does that mean it artificially adjusts your capacity at that three months interval, or it simply "catches up" to reality that existed based on your heat and usage?

It looks really artificial in nature.

Anyone remember apple getting caught artificially down rating phone batteries? They said it was to keep the phone optimized, but many suspected it was to push you toward buying a new product. Of course Nissan also has to be able to honor their warranty, which is 8 years / 1000,000 miles promised to what, 70% of original capacity? You'd think artificially down-rating would be a dumb thing to do.