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Makes And Models => Zero Motorcycles Forum | 2013+ => Topic started by: PlatPays on October 12, 2016, 03:37:08 AM

Title: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: PlatPays on October 12, 2016, 03:37:08 AM
Hi,
I have managed to read the log files of my Zero S 2015.
Thanks to the decoder utility I can see many details, thanks.

However I have a concern about two messages that occur on almost every ride / charge.
1. Even if my SOC is well above 60% I get the message Batt Dischg Cur Limited on most of my rides.
2. Almost every time I charge, there is the message on Low Chassis Isolation.
Should I be concerned and contact my dealer ?
The bike is driving well

An example is copied here and I attach a summary of the messages as well.
Line 677:  00665     08/16/2016 13:34:17   Batt Dischg Cur Limited    633 A (91.73913043478261%), MinCell: 3681mV, MaxPackTemp: 21C
Line 753:  00741     08/16/2016 14:41:06   Low Chassis Isolation      100 KOhms to cell 3

Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Kocho on October 12, 2016, 04:05:17 AM
I had a low isolation fault warnings and errors on my '15. The dealer replaced the motor controller and that was fixed. There is also a firmware update that you might get installed as well. Mine drove fine though, and no low power messages in my case.   
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: kashography on October 12, 2016, 12:32:49 PM
A also have the "Batt Dischg Cur Limited" under 65% charge or so. I think that is normal, but not sure.
Also i have the "Low Chassis Isolation" Errors, i have no idea if it has something todo with the total-breakdown of my zero, but i will report again if so! ;)
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Kocho on October 12, 2016, 05:38:28 PM
I don't think you should have the limited batt discharge under 65%, that's well within normal operating range and you should not be feeling reduced power anywhere near there. You might get limited power at lower SOC, but 65% more than half full... Does the error show on the dash or only in the logs?
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Skidz on October 12, 2016, 08:27:52 PM
My 2016 DSR is showing the same behaviour in the logs...

PackTemp: h 31C, l 31C, PackSOC: 71%, Vpack:101.058V, MotAmps: 151, BattAmps: 172, Mods: 10, MotTemp:  78C, CtrlTemp:  39C, AmbTemp:  21C, MotRPM:4246, Odo:   37km
Batt Dischg Cur Limited  ;652 A (94%), MinCell: 3593mV, MaxPackTemp: 31C
PackTemp: h 32C, l 31C, PackSOC: 69%, Vpack:102.380V, MotAmps: 106, BattAmps:  99, Mods: 10, MotTemp:  71C, CtrlTemp:  37C, AmbTemp:  21C, MotRPM:3507, Odo:   39km
Batt Dischg Cur Limited  ;675 A (97%), MinCell: 3646mV, MaxPackTemp: 32C
Riding                   ;PackTemp: h 32C, l 32C, PackSOC: 67%, Vpack:100.859V, MotAmps: 144, BattAmps: 153, Mods: 10, MotTemp:  69C, CtrlTemp:  37C, AmbTemp:  21C, MotRPM:4194, Odo:   40km
Batt Dischg Cur Limited  ;646 A (93%), MinCell: 3589mV, MaxPackTemp: 32C

Also the isolation errors:

Low Chassis Isolation    ;100 KOhms to cell 6
Charging                 ;PackTemp: h 29C, l 27C, AmbTemp: 18C, PackSOC: 52%, Vpack:102.870V, BattAmps:  -8, Mods: 01, MbbChgEn: Yes, BmsChgEn: No
Low Chassis Isolation    ;100 KOhms to cell 3

At first that seemed a bit weird but since the bike isn't really holding back?
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Kocho on October 12, 2016, 09:09:03 PM
So I read your messages more carefully - looks like the "limit" is just minor, less than 10% decrease, and only shows in the logs, not an error code on the dash, as I had incorrectly assumed from skimming the message quickly. Mine had errors about low isolation pop-up on the dash, which lead to the warranty replacement of the controller. I have not checked the logs since ...
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: acacia1731 on December 13, 2016, 12:48:48 AM
PackTemp: h 31C, l 31C, PackSOC: 71%, Vpack:101.058V, MotAmps: 151, BattAmps: 172, Mods: 10, MotTemp:  78C, CtrlTemp:  39C, AmbTemp:  21C, MotRPM:4246, Odo:   37km
Batt Dischg Cur Limited  ;652 A (94%), MinCell: 3593mV, MaxPackTemp: 31C

So I read your messages more carefully - looks like the "limit" is just minor, less than 10% decrease, and only shows in the logs

Are you saying that the "(94%)" number above means the bike is decreasing current by 6%?  I am looking through a log file from a 2015 FX full discharge and I see that number dropped pretty consistently with my perception of power cutback (data below).  There is another thread discussing algorithm - any correlation?

Batt Dischg Cur Limited
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Kocho on December 13, 2016, 03:51:17 AM
That's what I am guessing, but I have no data or observations to back it up. On my '15 SR I have not really noticed decrease in power or top speed until I am into the 20% or so left on the battery, at which point it is rather obvious there is a strong decrease in both. I have not been looking for signs of decreased power/top speed that intentionally though - I just notice it when it is quite strong at low SoC. 5-10% I doubt I'd notice ...
Title: Re: Batt Dischg Cur Limited and Low Chassis Isolation
Post by: Doug S on December 13, 2016, 04:09:08 AM
I have a 2014 SR, and I used to be able to feel it starting to cut back very early, in excess of 50% SoC. But Zero recently replaced my battery with a 2016 when it was having some repairs done, presumably reprogrammed everything, and now it doesn't cut back until quite a bit lower -- I'm pretty sure I feel no cutback at all until under 20%.

I'm pretty sure I haven't been imagining things, and I think Zero did it that way on purpose. Maybe the newer batteries can handle more discharge current than the older chemistries, or maybe they just got more information from Farasis on the exact shape of the SoC vs. allowable discharge current curve. I wouldn't be terribly surprised if even Farasis is still figuring that out -- the ultimate answer concerns how many cycles the battery lasts, so that sort of testing could take a long time. If you don't REALLY know the impact of allowing high discharge currents at medium SoC, better to play it safe than allow currents that could possibly cause premature failure in people's bikes.