# not getting full output from zilla any more ?



## dtbaker (Jan 5, 2008)

this issue is followup to an issue I had after diddling with zilla settings to test the effect of limiting motor voltage. I think I have all settings back to where they were, with everything 'wide open'. I set allowable motor voltage ABOVE my expected end-of-charge voltage, I set battery limit and warn values below where I expect the pack to sag under full load while operating near nominal voltage for most of the SOC.

My car is running again, it seems to be limiting the amps to about 500 instead of full 1000 I used to get. Not sure why.... any ideas?

I've lowered the b)LBVi and b)LBV to the point I don't think they are triggering, but it sure FEELS like something is clamping down right at 500 amps.

can anybody share some insight into the settings that 'limit' output and how that are inter-related in the Zilla? I am thinking perhaps I am not understanding all the motor/battery limit settings.

My nominal pack voltage is 156v (169v at eoc). here are the key settings I have at the moment:

battery
a)1000 v)119 i)129

motor
a)1000 v)175


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## TheSGC (Nov 15, 2007)

Do you have the liquid cooling setup for the Zilla?


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## dtbaker (Jan 5, 2008)

TheSGC said:


> Do you have the liquid cooling setup for the Zilla?



yes. I do have liquid circulation.... this 'throttling' to 500 amps is occurring right from the get go, system not even warm.


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## EVfun (Mar 14, 2010)

Can you drive the car while a laptop is receiving the DAQ data? This would allow you to scroll back up and see what was going on.

Is it possible that the zilla is in valet mode or reverse mode, and so using different limits? Both of these are engaged simply by applying power to the correct hairball pin (13 or 8 respectively.)

One last thought is to check out what controller the hairball thinks it is driving. Make sure Option menu item "p" is set correctly.


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## dtbaker (Jan 5, 2008)

EVfun said:


> Can you drive the car while a laptop is receiving the DAQ data? This would allow you to scroll back up and see what was going on.


hhhmmm, I could probably have my laptop in passenger seat and see if Operating status code indicates WHAT limit is in effect. Hard to look over when accellerating at 500+amps. I dunno how big the scroll buffer is, but might try this.



EVfun said:


> Is it possible that the zilla is in valet mode or reverse mode, and so using different limits? Both of these are engaged simply by applying power to the correct hairball pin (13 or 8 respectively.)


This seems remote, I didn't change any pins and the DAQ3 last column indicated F direction, which would apply F limits (it woked fine before I diddled with the motor voltage limit.



EVfun said:


> One last thought is to check out what controller the hairball thinks it is driving. Make sure Option menu item "p" is set correctly.


good idea, but I did double check that. I even tried running it both on and off, which made no difference surprisingly.


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## TheSGC (Nov 15, 2007)

Have you cleared any errors on the Zilla? Even if there aren't any, try clearing the error codes, there might be some false fault that's limiting the current.


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## dtbaker (Jan 5, 2008)

yes, cleared error codes before this last run 'just in case'.

ok, I was able to peek at the DAQ3 output while driving.... the Operating status changed from 30 (normal) under light acceleration to 26 (battery voltage limit active) when under hard acceleration.

this doesn't seem too likely as I have LBV=119, LBVI=129

I can't remember what I had it set to before, but I don't think it was any lower.... given that my nominal pack voltage is 156, I don't think I have ever seen it sag below 135 under full load before....

I guess the question becomes whether these values are realistic for max sag under 1000amp load now that the battery pack temp may be 50 degrees rather than 60+ ?


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## dillond666 (Dec 27, 2010)

I take it you have the hairball scaling set for a Z1K ?

Thats flag "P" in the Options menu.

Should be set to ON for a Z1K


EDIT sorry, just noticed this has been suggested already.


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## dtbaker (Jan 5, 2008)

...just tried a W reset, and went thru all settings. Still no improvement, clamps to somewhere between 500-600 amps, NOT the 900+ I was getting before at full throttle....

hhhmmmm.....no error codes, just the Q3 showing operating status that battery voltage limit swings into effect, when it shouldn't according to the setting. I have not tried lowering the BVL way low (its at about 2.5vpc x 48cells=120v), but might just to see if this has any effect.

for those of you attempting to pull 1000 amps, how much sag do you expect to see? or, where do you set YOUR BLV and BVLi in relation to avg vpc for your pack nominal?


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## z_power (Dec 17, 2011)

I'd hook a voltmeter temporarily to controller's B+/B- and took a test drive to see what is the value during acceleration - better know than suspect...


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## dtbaker (Jan 5, 2008)

ok, new information....

I lowered the b)v=LBV setting to 99v (which would be 2.1vpc average) and got back up to about 900 amps max load. This is telling me that the sag under 1000 max motor amps is dragging my cells down to pretty close to 2.0v... so once again, zilla was doing what it was supposed to, and my lack of info in that the cells will sag all the way down to 2.1 vpc at 1000 amps was the 'problem'.

Is that what you all are seeing? are you seeing sag to 2.0 vpc at 1000 amps with CALB cells?

followup question I have is that if I leave the battery indicator setting b)i=BVLI higher, say at 120v (2.5vpc) or more, will that clamp motor amps, or does that just turn on the visual indicator? if it is just visual, I would turn it further up so the indicator light might come on when pack voltage drops to 3.0vpc when at NO load, indicating low state-of-charge under no load.


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## TheSGC (Nov 15, 2007)

I don't even push my CALB SE 180AH past 2.2C (400A) so I've never seen past 2.5v, usually never past 3.0v. I'm probably going up to 3C once I start more highway driving.

When ever I hit my LVI I usually get clamped current, but it's been at what ever I set my max current to (currently 620 A).


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## gdirwin (Apr 7, 2009)

My Zilla Z1KHV settings are:
a)BA, v)LBV, i)LBVI
1000 115 129

115 LBV/46 cells is 2.5 V per cell.

I am able to pull 1000Amps out (using Thundersky 200AH cells) if the cells are above 0C - if they are really cold then there is a lot more sag and the performance drops. That said, I have been daily driving for about 3 years now (including at extremely low temperatures) and my pack is definitely aging (likely due to aggressive driving - ie too many 5C starts!).


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## dtbaker (Jan 5, 2008)

gdirwin said:


> My Zilla Z1KHV settings are:
> a)BA, v)LBV, i)LBVI
> 1000 115 129
> 
> ...


interesting point of data there.... you're getting significantly less sag with 200ah cells than I am seeing with 100ah. But yes, I am asking for the occasional 10C burst for a couple seconds when I just HAVE to blow the doors off some kid in a tuner at the light.


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## gdirwin (Apr 7, 2009)

Hi Dan - sorry I missed where you had only 100AH cells (not a good comparison to my 200AH cells).

But the point is that both of our packs are probably degrading due to many high C starts...


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## dtbaker (Jan 5, 2008)

gdirwin said:


> Hi Dan - sorry I missed where you had only 100AH cells (not a good comparison to my 200AH cells).
> 
> But the point is that both of our packs are probably degrading due to many high C starts...


I mis-typed... my Swift has 100ah cells, the Miata has 130ah cells, so not quite as badly abused. In fact, I wonder if high-C use has actually been proven to degrade, and if so how much and to what degree given duration and C rate?

I know that even when I am accelerating flat out, the system only shows 900+ amps for a second as my rpm go from about 2500-3500, and I usually have a fair bit of time between hard accell... not like a racecourse hammering every turn for minutes. I wonder what the internal cell temp actually is, how fast it dissipates, and what the cutoff temp is where 'damage' or plating or whatever starts to occur.


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## mk4gti (May 6, 2011)

Maybe do a "once over" of all the cell connections. I had performance issues in the past and it was a bad cell connection. my two cents.


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## dtbaker (Jan 5, 2008)

mk4gti said:


> Maybe do a "once over" of all the cell connections. I had performance issues in the past and it was a bad cell connection. my two cents.


I do check cell connections annually, no problems. The issue was resolved by lowering my battery LBV (further than expected required) to accomodate for the sag when under heavy load. I left the LBVI indicator up higher since I want to notice voltage dropping when I am at rest, but had to lower the LBV to 2.0vpc x 48 to get back my full 1000amps.


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## TheSGC (Nov 15, 2007)

The CALBs really aren't spec'd for 10C, my SE180AH have a max spec of 1000a for 10 seconds (5.6C), so pushing 1000A in your 130AH or 100AH is probably be killing them.


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## dtbaker (Jan 5, 2008)

TheSGC said:


> The CALBs really aren't spec'd for 10C, my SE180AH have a max spec of 1000a for 10 seconds (5.6C), so pushing 1000A in your 130AH or 100AH is probably be killing them.



maybe... time will tell. 

On the good side, I rarely discharge more than 50%DOD on any given day. Only twice in 5000 miles have I taken them down to 80%DOD.

I tried turning down the output to clamp at 5C, and it just isn't anywhere near as much fun when you KNOW there is more available.  The difference between 600amps and 1000 is what takes it from being good, to REALLY FUN.

My hope is that the brief 1000/130=7.7C accelerations aren't generating enough internal heat to do any real damage to the electrolyte since they only pull that load for a few seconds at a time with plenty of rest between. I don't have any way to monitor internal temp of course, so we'll just have to see....


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## EVfun (Mar 14, 2010)

Wow, and I thought I was harsh, running my Thunder Sky cells up to 5C. When warm they only sag to 2.8 volts per cell, but it gets worse as they get colder. I don't drive the buggy much in the winter.

I'm using little 60 amp hour cells and generally set my Zilla current limits to 300 battery amps, 900 motor amps. I have the low battery voltage indicator set to 107 volts and the minimum voltage set to 97 volts. Of course, I'm only pushing a 1200 lb. car around. I just bought some additional cells, unused but made in May 2009 (my current cells are February 2010,) so I will jump the pack from 39 cells to 53 cells.


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## dtbaker (Jan 5, 2008)

EVfun said:


> Wow, and I thought I was harsh, running my Thunder Sky cells up to 5C.



yeah.... it's irresistible to dial it up when you have it though.


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