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Re: The 40KWH Battery Topic

Posted: Wed May 08, 2019 9:43 pm
by LeftieBiker
jdcbomb wrote: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?
Your car was built a month earlier than mine, and after a year or so we both have about the same SOH. Good so far.

Re: The 40KWH Battery Topic

Posted: Wed May 08, 2019 9:44 pm
by lorenfb
danrjones wrote:Interesting

It seems resding through here that many notice their hx increase at first when new. It will be interesting to see how long it does.
That implies that the battery has become more efficient in the short term (a few months to a year) after being placed in service.
In the long run, it correlates with SOH.

Re: The 40KWH Battery Topic

Posted: Wed May 08, 2019 9:50 pm
by LeftieBiker
As far as I can tell, the Hx reading is no longer any help at all, starting with the 40kwh packs. It makes no obvious sense as it once did...

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 2:00 am
by kovadam
For me Hx has increased since I got the car to about 118.5% then declined to ~112%, now it started to increase again, and is now around 114%.

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 3:04 am
by LeftieBiker
kovadam wrote:For me Hx has increased since I got the car to about 118.5% then declined to ~112%, now it started to increase again, and is now around 114%.

That's what I mean. I assume that your SOH has done nothing but drop?

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 6:11 am
by kovadam
Yep, it drops more or less constantly. Now aftet 13000km I have 96.93% SOH, it was 99.36% when I got the car from the dealer. It dropped 0.01% every day in autumn, stopped to drop in winter (like only 0.01% per week or so), then in february there was 1 bigger drop, like 0.5% and in march agai . Now it is like in winter, dropping 0.01% every few days/week .
When Hx goes upwards, it drops slower, when going down, SOH drops faster... This is my experience.

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 7:11 am
by danrjones
jdcbomb wrote: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?
Mine is really early in its "in service" life, but a fact I didn't report before is that the build date was 3/18 according to the door.
So it was sitting for a full year, through a hot Palmdale summer, before I got it a week ago.

As of this AM:

AHr 112.68 SOH 97.61 Hx 98.16 QC 3 L1/L2 16 REAL ODO 228

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 8:55 am
by lorenfb
LeftieBiker wrote:As far as I can tell, the Hx reading is no longer any help at all, starting with the 40kwh packs. It makes no obvious sense as it once did...
To most before, it didn't make much sense. Never really could understand the preoccupation some have/had. SOH or the ratio of present
Ahrs to max Ahrs are more than adequate to assess the battery's condition.

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 8:58 am
by SageBrush
lorenfb wrote:
LeftieBiker wrote:As far as I can tell, the Hx reading is no longer any help at all, starting with the 40kwh packs. It makes no obvious sense as it once did...
To most before, it didn't make much sense. Never really could understand the preoccupation some have/had. SOH or the ratio of present
Ahrs to max Ahrs are more than adequate to assess the battery's condition.
That is mostly my opinion too although I thought Hx was a marker of battery resistance.

Re: The 40KWH Battery Topic

Posted: Thu May 09, 2019 9:11 am
by lorenfb
SageBrush wrote:
lorenfb wrote:
LeftieBiker wrote:As far as I can tell, the Hx reading is no longer any help at all, starting with the 40kwh packs. It makes no obvious sense as it once did...
To most before, it didn't make much sense. Never really could understand the preoccupation some have/had. SOH or the ratio of present
Ahrs to max Ahrs are more than adequate to assess the battery's condition.
That is mostly my opinion too although I thought Hx was a marker of battery resistance.
Hx declines as the battery ages, as has been noted on MNL. Battery resistance increases with battery age. Given that, a logical
conclusion is that Hx represents the ratio of the new/original battery resistance to the battery resistance as it ages (present),
or the ratio of conductances (present/new).

With regard to the 40kWh battery and Hx, it's possible that the original BMS firmware for Hx wasn't tweaked for compatibility.