The 40KWH Battery Topic

I did initially consider that, but my breaker panel is flush mounted and I have stucco, so getting the conduit out of the panel would not be trivial nor clean looking.

My thought was to actually run wire up out the panel in the wall (just like the rest), into the attic, over about four feet, and drop down again. That would avoid trying to drill and pull wire horizontally through studs inside the wall.

I could still hardware it in that design as well, just as a junction box with conduit coming out instead of a plug.

Check your local requirements, but you should be able to run indoor cable to the wall, then UF (Underground Feed) rated hard-plastic-encased cable through the wall and into the back or side of the EVSE, or UF cable for the whole run. UF cable is a PITA to strip, though.

Thanks guys

I'll figure out something

Back to battery questions

Why did my level 1 / 2 charges jump from 6 to 13 in one night?

I'm sure its total statistical noise but I'm loosing .01 soh each day, same with AHrs but HX has been going up about 0.1 per day.

Timer charges tend to get counted twice. It's a known, longstanding glitch. Were there any brownouts, no matter how brief?

Not that I'm aware of.

I'll see what it does tonight on lvl 1.

I charged last night for 8 hours exactly on 120v and it went from 48% to 74%, which actually seems pretty reasonable given 1400 watts it says its doing. (~ 1400x8 = 11.2 Kw, 74% - 48% = 26%, not including losses and such, but its close)

I have noticed, as someone here pointed out, that there doesn't seem to be much heat generated from Lvl1. At 10pm the battery temp bar was exactly in the middle and at 6:30am, right when it finished charging (10:30p to 6:30a) the battery temp bar was actually 2 notches below half. So despite charging all night it actually got colder due obviously to the lower temperatures outside.

So my question, even though I do need lvl 2 charging, I'm wondering if charging lvl1 sometimes when its very hot at night would be better for the battery. Once I get a lvl2 installed I can compare.

danrjones said:

the battery temp bar was actually 2 notches below half.

Click to expand...

Is your temp gauge segmented (notches)?

danrjones said:

So my question, even though I do need lvl 2 charging, I'm wondering if charging lvl1 sometimes when its very hot at night would be better for the battery. Once I get a lvl2 installed I can compare.

Click to expand...

Yes. The battery power dissipation is I^2 X R (battery resistance) while charging;

Power (L1) = I ^2 X R
Power (L2) = (2I) ^2 X R = 4 X Power (L1)
but T2 = T1/2

So the heat energy (power X time) supplied to battery is 2X for L2 versus L1.

You can adjust the numbers based the actual L1 versus L2 currents and times.

lorenfb said:

danrjones said:

the battery temp bar was actually 2 notches below half.

Click to expand...

Is your temp gauge segmented (notches)?

danrjones said:

So my question, even though I do need lvl 2 charging, I'm wondering if charging lvl1 sometimes when its very hot at night would be better for the battery. Once I get a lvl2 installed I can compare.

Click to expand...

Yes. The battery power dissipation is I^2 X R (battery resistance) while charging;

Power (L1) = I ^2 X R
Power (L2) = (2I) ^2 X R = 4 X Power (L1)
but T2 = T1/2

So the heat energy (power X time) supplied to battery is 2X for L2 versus L1.

Click to expand...

hmmm...
L2 may be twice the current but it is also twice the voltage so
T2 = 0.25 of T1

SageBrush said:

lorenfb said:

danrjones said:

the battery temp bar was actually 2 notches below half.

Click to expand...

Is your temp gauge segmented (notches)?

danrjones said:

So my question, even though I do need lvl 2 charging, I'm wondering if charging lvl1 sometimes when its very hot at night would be better for the battery. Once I get a lvl2 installed I can compare.

Click to expand...

Yes. The battery power dissipation is I^2 X R (battery resistance) while charging;

Power (L1) = I ^2 X R
Power (L2) = (2I) ^2 X R = 4 X Power (L1)
but T2 = T1/2

So the heat energy (power X time) supplied to battery is 2X for L2 versus L1.

Click to expand...

hmmm...
L2 may be twice the current but it is also twice the voltage so
T2 = 0.25 of T1

Click to expand...

You can adjust the numbers based the actual L1 versus L2 currents and times.

Click to expand...

It sounds like Lvl2 produces more heat total, but even it was the same heat it would be a much shorter time, which wouldn't allow for it to disperse.

I checked at lunch and the single long lvl 1 charge increased my charge count in leafspy by 3.


I also noticed today my Hx jumped up by a full 0.1. SOH stayed the same so far today.
Reading through the threads here I have discovered Hx was the old battery health meter before SOH was created / discovered.
There didn't seem to be a consensus for what it mean now, especially for the 2018's.

anyway, 1 lvl 1 night = 3 charges.

lorenfb said:

SageBrush said:

lorenfb said:

Is your temp gauge segmented (notches)?



Yes. The battery power dissipation is I^2 X R (battery resistance) while charging;

Power (L1) = I ^2 X R
Power (L2) = (2I) ^2 X R = 4 X Power (L1)
but T2 = T1/2

So the heat energy (power X time) supplied to battery is 2X for L2 versus L1.

Click to expand...

hmmm...
L2 may be twice the current but it is also twice the voltage so
T2 = 0.25 of T1

Click to expand...

You can adjust the numbers based the actual L1 versus L2 currents and times.

Click to expand...

Click to expand...

Remember, during any charge mode (L1/L2/L3) the battery voltage is basically the same, approx. 370 - 400. During L1/L2 the EVSE output voltage is changed (scaled) by the inverter to the 370 - 400. For L3, The DC source is in the same D.C. range.

This will be interesting in July.

Last night at 10pm it was 80f and the battery temp was smack in the middle,
lvl 1 charged all night, 60f this morning at 6am, and the battery temp was down a couple chunks (not sure if its bars, all I see is a constant bar left to right)

But in July when its 105 at 10pm and 78 at 6am, I'm wondering if lvl 1 charging all night (8 hrs) or lvl 2 charging for say 2 hours (4am to 6am) will end up thermally better / worse.

I guess I can try both and see.

^^^
Use Leaf Spy instead of guessing with the bars.

danrjones said:

This will be interesting in July.

Last night at 10pm it was 80f and the battery temp was smack in the middle,
lvl 1 charged all night, 60f this morning at 6am, and the battery temp was down a couple chunks (not sure if its bars, all I see is a constant bar left to right)

But in July when its 105 at 10pm and 78 at 6am, I'm wondering if lvl 1 charging all night (8 hrs) or lvl 2 charging for say 2 hours (4am to 6am) will end up thermally better / worse.

I guess I can try both and see.

Click to expand...

While you should avoid charging at all if the battery temp is 7 bars/60% or higher, I agree that L-1 usually produces less battery heat. My GUESS is that it adds heat at about the same rate the pack radiates it away.

lorenfb said:

lorenfb said:

SageBrush said:

hmmm...
L2 may be twice the current but it is also twice the voltage so
T2 = 0.25 of T1

Click to expand...

You can adjust the numbers based the actual L1 versus L2 currents and times.

Click to expand...

Click to expand...

Remember, during any charge mode (L1/L2/L3) the battery voltage is basically the same, approx. 370 - 400. During L1/L2 the EVSE output voltage is changed (scaled) by the inverter to the 370 - 400. For L3, The DC source is in the same D.C. range.

Click to expand...

I had to write this out. I compared

L1 at 120v, 16 Amps
L2 at 240v, 32 Amps
L3 at 480v, 100 Amps

The arithmetic worked out as
L1: H heat energy per energy E
L2: 4H heat energy per energy E
L3: 25H heat energy per energy E

Any mistakes ? If not then I'll say that compared to DCFC, L2 is a gentle charging routine

The actual charging rate to the car, after parasitic losses, for L-1 is more like 11 amps. There are 16A L-1 EVSEs but they are not the norm and require a 20A circuit rather than the usual 15A household circuit. 12A units are typical.

cwerdna said:

^^^
Use Leaf Spy instead of guessing with the bars.

Click to expand...

Thanks

2 month update 2019 Leaf S - no QC port, San Diego

Date-------- SOH--- Ahr---- Hx----- Odo--- # L1/L2-- Days -- Loss- Yearly SOH Loss Run Rate
3/8/2019 99.39% 114.74 104.14% 649 24
3/15/2019 99.31% 114.64 106.01 882 32 7 0.08%
4/7/2019 99.06% 114.35 110.42 1606 56 30 0.33% 4.0%
5/8/2019 97.84% 112.95 113.36 2698 91 61 1.55% 9.3%

I usually charge 80-90% and never go below 20%.

2018 SV - 40 kWh - 2018/09 Manufacture Date - In Service 2019 January.

AHr 111.47 - SOH 96.56 - Hx 115.05 - ODO 6,176 mi - QC 57 - L2 155

Thoughts on how this compares to other 2018 units?

Northwest car 2018 SV, in service Mar 29/18
AHr 106.86 - SOH 92.57 - Hx 118.60 - ODO 25,512 km- QC 7 - L2 443