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[herculeesjr]

It was a nice Saturday night and I wanted to go for a ride. I wanted to just cruise and see how far I can ride going 75mph on the interstate with saddlebags and everything else attached, plus I wanted to measure how many KWh go back into the bike charger with a fully depleted battery. So I rode nonstop one direction on the interstate with Custom mode set to 75mph. Once I reached 45% I took the next exit to turn around and headed back home. I was at 4% battery left on the dash pulling off the interstate and an average of 135Wh/mile. It was constant 75mph with zero slowdowns except taking the exit to turn around at the halfway point, mostly level terrain too.

I rode further doing 55mph till it dropped to 0%, dash said I had 4.8miles left. I then rode around town within a mile of my house till it dropped to 1.2miles left and I rode back home not wanting to push it further or literally have to push it home. A total of 60miles riding from 100% to 0% on the dash with 1.0miles range remaining once I parked.

I pulled the logs; when I pulled in the driveway and parked the logs state I still had 3% battery left (0% on the dash) with a battery voltage of 93.696v, and 1.0miles of remaining range on the dash. So unlike what multiple forum posts state, 95.000v is not battery pack minimum. I'm curious if anyone has done any research as to what the real battery cutoff voltage is?

Also, the charger took 9.87KWh to fully recharge the battery, but I can't find any other posts where people measured how many KWh were used to recharge their bike from dead to full. I have a 2017 DS ZF13.0.

[TheRan]

Well technically the cells are good down to 2V so that's 56V for all 28 cells, plus a little bit because they won't be perfecting balanced and some will be above that minimum. However that's just the resting voltage and it will sag under load to below that minimum so for actual usage it would need to cut out a fair bit higher than 2V.

As for the state of charge reading it's not an instantaneous measurement of the battery voltage because then it would jump around constantly, dropping under load and then recovering. Like wise while your battery may have dropped to 93V it probably would have recovered to 95V or more if you let the bike sit for a while. As the Unofficial Manual states the SoC can be correlated to a certain voltage at rest, but under an actual load there will be filtering and averaging going on.

https://zeromanual.com/wiki/State_of_Charge

[herculeesjr]

Looking through your link, followed by a ton of looking around the unofficial manual website, I found this "Zero will let you discharge to about 88 volts" at https://zeromanual.com/index.php?title=BMS/SoC_Estimation .
So I guess the bike had a decent bit of life left in it before it cut out and shut down, but I'm not sure I want to ride around that low ever again. I pulled the BMS logs today to see the full discharge and then recharge. This was at its lowest:

Code: [Select]

07947     05/01/2021 19:02:22   Discharge level            092 AH, SOC:  2%, I:000A, L:3432, l:3447, H:3449, B:017, PT:039C, BT:034C, PV:96425, M:Bike On
 07948     05/01/2021 19:02:22   SOC:88224,89877,92553,104000,12,5,2,17   
 07949     05/01/2021 19:02:22   Discharge cutback          45%
 07950     05/01/2021 19:02:22   354AWhich I'm not sure what most of that means, I imagine more digging through the unofficial manual will give me a breakdown on all those numbers. This is right before the charger shut off:

Code: [Select]

08058     05/02/2021 02:49:14   Discharge level            000 AH, SOC:100%, I:000A, L:4153, l:4149, H:4160, B:007, PT:026C, BT:044C, PV:116432, M:Idle
 08059     05/02/2021 02:49:14   SOC:0,94677,0,104000,100,100,100,-5   
 08060     05/02/2021 02:49:33   Voltage Across Contactor: 104467mV (Okay)
I think it's saying I was limited to 45% of max torque, 2% charge remaining, lowest cell was 3.432v, highest cell was 3.449v, 96.425v pack voltage, and I had used 92Ah from the battery (not sure if that includes regen)? Which suggests like you said the bike sitting let voltage go back up a bit.

With this info how can I go about comparing my battery capacity to a new battery pack?

[TheRan]

A 2017 would use 29Ah cells. So if that 92Ah used is correct then I would assume 4x 28 cells in series for a total of 116Ah, and with that large a difference I would also assume regen is probably taken into account.

You're correct on most of those other points, although it wouldn't be 45% torque because the power needed to achieve that amount of torque will vary so it will just be 45% of whatever the maximum current draw is (I think about 460A continuous and 800A for 10 seconds) and thus 45% power. The PT and BT relate to temperatures, PT probably being pack temperature because PV is pack voltage but not sure what BT would be. B would be the difference in cell balance, so 0.017V when discharged and 0.007V when fully charged. The lowercase l is probably the average voltage.

[MVetter]

A 2017 would use 29Ah cells. So if that 92Ah used is correct

That may be what Farasis stamps on the cells but Zero's BMS only uses 26Ah. The ZF13 is a 104Ah pack. The ZF14.4 cells are recognized as 28.5AH by the bike for a total of 114Ah.

Seeing that the 13 pack is 104Ah with a nominal 102vdc, I would expect a full charge to be no more than 10.6kWh.

[herculeesjr]

So if I wanted to do a completely perfect battery health test I would want to disable all regen and redo this test, getting as close to 88v as possible, then seeing how many Ah I used in the BMS logs? Or is there a more preferred way? I can't seem to find any complete info on how to test the battery health so I guessed up most of this.
I don't believe there is anything wrong with my battery, I'm just curious to find out how good of condition it's in since I'm now the bikes third owner.

[MVetter]

The standard capacity test I recommend is to buy or borrow a Kill-A-Watt meter. Ride the bike to empty. As in it absolutely refuses to go any further. Done. Dead. Finito.

Attach the meter to a wall outlet and do a full charge with the onboard charger. Report those numbers back here.

[Richard230]

I found my old post regarding riding my 2018 Zero S with PT down to "00" SOC and then recharging it overnight. A full recharge took 15.1 kWh at 120V as measured by a Kill A Watt meter:  https://www.electricmotorcycleforum.com/boards/index.php?topic=8343.0

[MVetter]

Hm. That's actually a bit higher than I would have expected.

[herculeesjr]

Well with my battery pack down to 93-95v and a full overnight charge it took 9.87kWh from the outlet. So it sounds like my battery is pretty healthy if I were to assume there was even 0.2kWh left in it from me not riding it till it was completely dead. It still said I had 1.0miles left on the dash. I'm within 1kWh of your quoted 10.6kWh.

[flynnstig82r]

I’m only getting a maximum of about 6.8 kWh of charging into my ‘17 SR 13.0 so I think I have a pretty good case for a warranty replacement. I need to get a copy of last night’s power usage from Evercharge (my apartment building’s EV charger company) and then I’ll have my ducks in a row to submit a claim.

[Auriga]

I’m only getting a maximum of about 6.8 kWh of charging into my ‘17 SR 13.0 so I think I have a pretty good case for a warranty replacement. I need to get a copy of last night’s power usage from Evercharge (my apartment building’s EV charger company) and then I’ll have my ducks in a row to submit a claim.

I admire your independence, but Zero is just going to have the dealer or you  ride it form 100 to 0 1-3 times and then look at the logs to determine if it qualifies. They don't go off of EVSE logs or Kill-A-Watt readings.

[MVetter]

Yeah at first they were handing out replacement 14.4s like candy but they've become a bit more strict in the last year or so.

[flynnstig82r]

Good to know! Yesterday's ride was from 100 to 0 (on the dash) so that's one in the bag. I haven't pulled the logs yet so I can't say for sure what the discharge level will reveal. I'm assuming discharge level is what they go off of? Last time I had it down to 0% it said 093 Ah but I didn't start with a 100% charge so it can't be used for a claim.

To answer the OP, the ride I referenced was the kind of real "stick a fork in it" 0% that MVetter was talking about. The bike kept shutting off if I didn't operate the throttle with a surgeon's hand until I was eventually riding in the bike lane at 15-20 MPH and accelerating like a snail on quaaludes. Before it shut off for the last time and had to be pushed the remaining 3 blocks to my place, I had the pack voltage down to 90.6:

Code: [Select]

05045     04/04/2021 19:15:22   Riding                     PackTemp: h 37C, l 34C, PackSOC:  0%, Vpack: 90.621V, MotAmps:  60, BattAmps:  64, Mods: 10, MotTemp:  42C, CtrlTemp:  20C, AmbTemp:   6C, MotRPM:3407, Odo:72972km
Corresponding BMS log if anyone's curious:
[spoiler]

Code: [Select]

91211, M:Bike On
 06212     04/04/2021 19:23:32   SOC:82088,81015,93305,104000,11,0,0,23
 06213     04/04/2021 19:23:32   Discharge cutback           4%
 06214     04/04/2021 19:23:32   30A
 06215     04/04/2021 19:24:04   ERROR: Discharge Overcurrent: 52A ( limit=30A )
 06216     04/04/2021 19:24:04   DEBUG: Entered Discharge Fault State
 06217     04/04/2021 19:24:04   DEBUG: CAN NOT Receiving Syncs
 06218     04/04/2021 19:24:05   Contactor was Opened       Pack V: 91048mV, Switched V: 91057mV, Prechg Pct: 100%, Dischg Cur: -7250mA
 06219     04/04/2021 19:24:06   DEBUG: CAN Receiving Syncs
 06220     04/04/2021 19:24:29   DEBUG: CAN NOT Receiving Syncs
 06221     04/04/2021 19:24:34   Voltage Across Contactor: 24921mV (Okay)
 06222     04/04/2021 19:24:36   System Turned Off
 06223     04/04/2021 19:24:36   DEBUG: CAN Link Is Down
 06224     04/04/2021 19:24:37   Discharge Overcurrent Cleared
 06225     04/04/2021 19:24:37   DEBUG: Entered Idle State
 06226     04/04/2021 19:24:40   System Turned On
 06227     04/04/2021 19:24:40   Rev:34,Build:2018-08-24_095615 506     banka 
 06228     04/04/2021 19:24:40   Pack:2016_monolith,Numbricks:4
 06229     04/04/2021 19:24:40   DEBUG: Entered Running State
 06230     04/04/2021 19:24:40   Discharge level            093 AH, SOC:  0%, I:  0A, L:3177, l:3197, H:3317, B:140, PT:037C, BT:033C, PV: [/spoiler]

[herculeesjr]

That seems to line up with the SOC page in the unofficial manual then. It states you can go down to roughly 88v before the bike absolutely quits, with 0% charge being at 92.4v. you were down below the "0%" where as I expected things can get tricky as it's more of a limp home mode.
I need to order a USB OBD adapter so I can see the BMS stats, just since I'm not actually having issues it hasn't been high priority.