map40home
Posts: 18
Joined: Sat Oct 26, 2019 11:41 am
Delivery Date: 26 Oct 2019
Leaf Number: 009238

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 5:40 am

jkenny23 wrote:
Wed Nov 20, 2019 6:53 pm
map40home wrote:
Wed Nov 20, 2019 6:34 pm
goldbrick wrote:
Wed Nov 20, 2019 5:52 pm


Buffering a signal means putting some sort of (usually) active component between the signal (which is the output of some circuit) and the inputs to the circuit it has to drive. A mechanical relay can do this or an electronic circuit can be used.

The basic idea is that if the output from one circuit component isn't compatible with the the inputs of the circuits it is connected to, something is inserted in between them to isolate or buffer the output from one circuit from the input to the next circuit. The incompatibility can be the amount of current required, rise/fall rate, voltage level, impedance characteristics, etc.

In this particular case, the concern is the amount of power (current * voltage) required to drive both relays, including the voltage drop through the longer wiring.
Got it. A mosfet or a triac circuit driving the load of the contactors drawing the power from the battery upon receiving the signal from the vmc comming from the control cables. Anybody has one already used in this application I can copy? Otherwise I can just do a generic one.
N-MOSFET or NPN relay circuit from here (non-inverting logic) will work: https://www.electronics-tutorials.ws/bl ... rcuit.html
Thanks!. I alfready got 5 double mosfet circuit boards on order (I know I am going to screw up at least one :))

map40home
Posts: 18
Joined: Sat Oct 26, 2019 11:41 am
Delivery Date: 26 Oct 2019
Leaf Number: 009238

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 6:09 am

Irling wrote:
Wed Nov 20, 2019 6:30 pm
map40home Congratulations on your purchase of an extra battery. What is your body? Zeo? Azeo?
How do you want to connect an extra battery, before or after the current sensor? How do you want to solve the turtle problem after using all 285 GiDs ?
Thanks. I am going to hookup right out of the battery. I don't know yet how I will address the 285 GIDs issue, but I will be happy to have that problem. Right now my car (a first gen 2011 US version with 27K miles) has 190 GIDs. Battery degradation is around 67%. The battery I bought should be around the same level, Gen 1, fully assembled, undameged, for $2K delivered to my house.
My plan is to lift the car, slide it under, hook it up and check it. Charge it while I am at it. Once I see the condition, take it apart, assemble it in a custom made aluminum or fiberglass box in the trunk, equilize voltage to the main battery, hook it up to the control mosfets and power cables and see what happens.
I also plan to upgrade the 12v battery because I am already seeing that the little lawn mower battery they put in will die very fast dragging all the extra electronics. I want to have a "always on" USB port to keep my tablet running with Leafspy pro charging all the time.
I normally carry a 240V split phase 6KW inverter generator for emergencies, which now I will need to relocate or not carry anymore.
I installed the heater upgrade yesterday and that worked great.
I'll keep everybody posted.

Daklein
Posts: 33
Joined: Fri Sep 06, 2019 7:58 pm
Delivery Date: 02 Sep 2019
Location: Hartland, MI

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 8:13 am

map40home wrote:
Thu Nov 21, 2019 6:09 am
plan is to lift the car, slide it under, hook it up and check it.
The control harness probably will not reach, without removing the main pack and putting the new one nearly into place.

Has anyone identified the round control connectors Nissan uses on the battery (and pdm/inverter)? Must be possible to purchase both sides and the terminals?
2014 Leaf S w/ 6.6kw charger & Chademo port, 24kWh ->=> 62kWh !! :o (working on it)

jkenny23
Posts: 99
Joined: Sat Aug 19, 2017 12:49 pm
Delivery Date: 19 Sep 2017
Leaf Number: 009318

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 10:29 am

Daklein wrote:
Thu Nov 21, 2019 8:13 am
map40home wrote:
Thu Nov 21, 2019 6:09 am
plan is to lift the car, slide it under, hook it up and check it.
The control harness probably will not reach, without removing the main pack and putting the new one nearly into place.

Has anyone identified the round control connectors Nissan uses on the battery (and pdm/inverter)? Must be possible to purchase both sides and the terminals?
They're custom and probably impossible to buy other than from an actual Leaf. You can try 3d printing one: https://www.diyelectriccar.com/forums/s ... source=amp

map40home
Posts: 18
Joined: Sat Oct 26, 2019 11:41 am
Delivery Date: 26 Oct 2019
Leaf Number: 009238

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 11:22 am

Daklein wrote:
Thu Nov 21, 2019 8:13 am
map40home wrote:
Thu Nov 21, 2019 6:09 am
plan is to lift the car, slide it under, hook it up and check it.
The control harness probably will not reach, without removing the main pack and putting the new one nearly into place.
I was thinking of getting the wire loose and putting the battery forward. I think I have enough reach, otherwise, I'll just drop the other battery and raise this one up for a few hours.
Once I reconnect the original battery, the error code should disapear, right?

mux
Posts: 233
Joined: Sat Jan 13, 2018 3:52 am
Delivery Date: 13 Oct 2011
Leaf Number: 6177

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Nov 21, 2019 11:38 am

jkenny23 wrote:
Thu Nov 21, 2019 10:29 am
Daklein wrote:
Thu Nov 21, 2019 8:13 am
map40home wrote:
Thu Nov 21, 2019 6:09 am
plan is to lift the car, slide it under, hook it up and check it.
The control harness probably will not reach, without removing the main pack and putting the new one nearly into place.

Has anyone identified the round control connectors Nissan uses on the battery (and pdm/inverter)? Must be possible to purchase both sides and the terminals?
They're custom and probably impossible to buy other than from an actual Leaf. You can try 3d printing one: https://www.diyelectriccar.com/forums/s ... source=amp
They're not custom, they are a catalog part from Yazaki. The trouble in getting those is that Yazaki doesn't sell through distributors so you have to be lucky that a japanese broker may stock a batch. Also, as with anything in Japan: good luck navigating anything there without speaking Japanese *very well*.

So in practice you can consider them custom and 3D printing is the best course of action. The pins mate well with a variety of standard issue connector pins like TE TH/.025 pins.

nlspace
Posts: 93
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Dec 12, 2019 3:51 pm

mux wrote:
Wed Nov 13, 2019 10:19 am
If parallelling each cell individually, the BMS will likely have too little balancing current available in the long term. The BMS in the Leaf uses table look-up for determining SOH, internal resistance, allowable charge and discharge rate, etc., which is chemistry-specific and really even cell-specific. Parallelling cells together with potentially different chemistries will make this useless and will possibly cause the battery to determine the wrong SOH, SOC and allowable current at different times.

Parallelling the entire pack together means one pack will not have cell-level balancing and monitoring. This will cause fire and death. You can't have a BMS-less pack.

If the Leaf's BMS were designed a little bit better, the first approach could actually work fine, but it's got the 285 GID maximum as well as monotonic degradation memory (meaning a battery can never get 'better', only 'worse' according to the BMS), which makes it hard to properly gauge capacity and SOC with the existing BMS. This can't really be solved with a CAN MITM workaround.
i didn't want to believe that this was really TRUE--that they are not actually measuring internal resistance, but that appears to be the case and it is a stupid, lazy approach in the software.

User dala has posted some CAN buss findings on github that identify PIDS based upon Nissan technical documents, https://github.com/dalathegreat/leaf_ca ... an_ZE0.dbc, looking at his files it appears to confirm some of these low-priority x5xx series pids. Real progress will require decoding and understanding the highest priority (lowest numbered) pids.

HX is the lookup table value of the internal resistance, a percentage of the original value. If HX is greater than 100%, then the IR is increasing (meaning cells are degraded). But how can code know if it is not really measured?
[edit: invert the ratio such that HX decreases as IR increases, then it should be less than 100%]

SOH is the capacity degradation rate, the monotonic factor mentioned above. Likely another table lookup possibly based upon time. This may be the Gradual Capacity Loss factor discussed in the FSM. Always less than 100%?

gids is the remaining capacity. It is likely the result of a calculation of the percentage of the original capacity available and sent to the dash segment meter. 3 gids is 1% of a 24 kwh pack.

Temperature is also a factor used in the calculation of available capacity, most likely for the IR table in addition to other items.

possible calculation scheme:
[CAPR]Remaining Capacity = [PID#]Original Cap x [SOH]degrade factor(t) x [HX]IR factor(T)
Last edited by nlspace on Thu Dec 12, 2019 6:55 pm, edited 1 time in total.

lorenfb
Posts: 2295
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Dec 12, 2019 5:12 pm

nlspace wrote:
Thu Dec 12, 2019 3:51 pm

HX is the lookup table value of the internal resistance, a percentage of the original value. If HX is greater than 100%, then the IR is increasing (meaning cells are degraded).
Typically on the pre-2018 (40 kWh) Leafs the Hx (%) decreased over time following the SOH, which indicates a ratio of conductances (GX/G0),
where G0 is the initial conductance of a new battery. Using resistance as the value and having the percentage decline over time,
then the ratio for resistance is R0/RX. Sample data from my Leaf have indicated a declining value for Hx over time. At least now there's
agreement that Hx is a ratio and not some actual value.

Here're my resistance values over time as SOH declined:

11/20/14 -13,700 miles, 76 mohms per LeafDD, 20 Deg, 73% SOC
11/27 -13,800 miles, 67 mohms per LeafDD, 25 deg, 63% SOC
11/30 - 13,900 miles, 56 mohms per LeafDD, 27 deg, 71% SOC
12/2 - 14.100 miles, 55 mohms per LeafDD, 28 deg, 67% SOC
12/16 - 14,500 miles, 89 mohms per LeafDD, 15 deg, 93% SOC
12/27/14 - 14,800 miles, 103 mohms per LeafDD, 11 deg, 24% SOC
3/10 - 17,400 miles, 60 mohms per LeafDD, 30 deg, 73% SOC
3/14 - 17, 550 miles, 56 mohms per LeafDD, 32 deg, 47% SOC
4/14 - 19,100 miles, 59 mohms per LeafDD, 25 deg. 38% SOC
5/4 - 19,989 miles, 64 mohms per LeafDD, 24 deg. 48% SOC
5/15 - 20,400 miles, 73 mohms per LeafDD, 20 deg. 41% SOC
5/22 - 20,700 miles, 58 mohms per LeafDD, 28 deg. 50% SOC
12/10/15 - 28,000 miles, 90 mohms per LeafDD, 19 deg. 92% SOC
4/5 - 32,000 miles, 74 mohms per LeafDD, 24 deg, 55% SOC
5/16 - 33,700 miles,89 mohms per LeafDD, 22 deg, 47% SOC
5/16 - 33.700 miles, 58 mohms per LeafDD, 31 deg, 76% SOC
10/5 - 39,300 miles, 100 mohms per LeafDD, 22 deg, 50% SOC
10/6 - 39,400 miles, 61 mohms per LeafDD, 30 deg, 51% SOC
10/7 - 39,500 miles, 80 mohms per LeafDD, 25 deg, 56% SOC
10/15 - 40,000 miles, 71 mohms per LeafDD, 27 deg, 45% SOC
10/30 - 41,000 miles, 74 mohms per LeafDD, 23 deg, 66% SOC
12/26/16 - 43,000 miles, 110 mohms per LeafDD, 13 deg, 77% SOC
6/10/17 - 49,600 miles, 89 mohms per LeafDD, 19 deg, 70% SOC
7/1/17 - 51,000 miles, 62 mohms per LeafDD, 33 deg, 44% SOC
8/15/17 - 53,400 miles, 61 mohms per LeafDD, 35 deg, 57% SOC
4/2/18 - 62,100 miles, 110 mohms per LeafDD, 18 deg, 94% SOC
6/13/18 - 65,000 miles, 84 mohms per LeafDD, 26 deg, 52% SOC
9/14/18 - 68,000 miles, 84 mohms per LeafDD, 27 deg, 57% SOC
10/30/18 - 70,000 miles, 93 mohms per LeafDD, 22 deg, 84% SOC
11/9/18 - 70,000 miles, 104 mohms per LeafDD, 22 deg, 89% SOC
11/30/18 - 70,400 miles, 88 mohms per LeafDD, 23 deg, 88% SOC
12/6/18 - 70,800 miles, 116 mohms per LeadDD, 13 deg, 33% SOC
1/30/19 - 72,300 miles, 86 mohms, per LeadDD, 23 deg, 45% SOC
5/29/19 - 74,476 miles, 102 mohms, per LeafDD, 19 deg, 89% SOC
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

nlspace
Posts: 93
Joined: Mon Jun 05, 2017 10:21 pm
Delivery Date: 06 Jun 2017

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Dec 12, 2019 7:09 pm

That's good data, and i like your resistance ratio better as it makes an easier calculation of multiplication factors.

It appears that the internal resistance increases as the temperature drops, that makes sense in that the cell chemical reaction is slower when colder.
HX factor from dala's github:
PID x5C0
SG_ LB_HistData_Degrade_IntRes_Coeff : 33|7@1+ (1,0) [0|100] "%" Vector__XXX


Does the SOH factor always decrease and is less than 100%. If you multiply the original pack Ahr size by the SOH %, to get the current Ahr.
Last edited by nlspace on Thu Dec 12, 2019 7:37 pm, edited 1 time in total.

lorenfb
Posts: 2295
Joined: Tue Dec 17, 2013 10:53 pm
Delivery Date: 22 Nov 2013
Leaf Number: 416635
Location: SoCal

Re: Extra Battery, How to Integrate with 24kWh Traction Battery?

Thu Dec 12, 2019 7:16 pm

nlspace wrote:
Thu Dec 12, 2019 7:09 pm

Does the SOH factor always decrease and is less than 100%. If you multiply the original pack Ahr size by the SOH %, to get the current Ahr.
That's correct. Ahr is basically the only battery parameter I follow, whether its to evaluate battery degradation or my remaining range.
For my basic range calculation, I use about 2 miles/Ahr, with a minimum of about 15 Ahrs as my minimum.
#1 Leaf SL MY 9/13: 74K miles, 48 Ahrs, 5.2 miles/kWh (average), Hx=70, SOH=78, L2 - 100% > 1000, temp < 95F, (DOD) > 20 Ahrs
#2 Leaf SL MY 12/18: 4.5K miles, 115 Ahrs, 5.5 miles/kWh (average), Hx=98, SOH=99, DOD > 20%, temp < 105F

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