[ausev] No-phantom-load: quick Zilla question

[Mark Farver]

In Brian's case his DC/DC use 50ma whenever its running (one of the 
major drawbacks of the Iota) which is larger than the Hairball's 20ma.

Interestingly Otmar designed the Hairball to be able to power down 
significant parts of itself to conserve power when the vehicle was off, 
but never implemented that feature becuase he didn't feel it was 
significant.

Before I got a DC/DC my solution for the MR2 was to wire the SLI input 
to ignition.  A second circuit wired in parallel to the SLI input has a 
relay that provides power to the hairball for about 2 minutes every time 
the driver's door is opened.  That way the Hairball can do its boot 
while I'm getting in the car and sitting down, and its ready to go by 
the time I turn the key.

Mark

tomsmail at wtez.net wrote:
>> that takes 10-20 seconds.
>>     
> Ah.  Good point.  I'll keep that in mind and wire a chicken switch on SLI to experiment with.
>
> I currently have no DC-DC, so 12V Aux power is limited, in my case.
>
> Thanks for the tip.
> Tom
>
> --- blasseter.cmpe01 at gtalumni.org wrote:
>
> From: "Brian Lasseter" <blasseter.cmpe01 at gtalumni.org>
> To: "AustinEV News Announcements and General Discussion" <ausev at austinev.org>
> Subject: Re: [ausev] No-phantom-load: quick Zilla question
> Date: Fri, 2 Jan 2009 21:54:16 -0600
>
> n Thu, Jan 1, 2009 at 10:57 AM,  <tomsmail at wtez.net> wrote:
>   
>> Regarding the first two of the three 12V inputs to the Zilla hairball, does anyone know WHY the "SLI" input must be on an "always on" circuit?  As I understand it the parameters are placed in eeprom.  If not, then what have been the observed consequences of tying the SLI and KEY inputs to the same "run" circuit?
>>     
>
> I was confused by this too... however I can confirm what Ken says
> about the current draw being tiny in comparison to other things (like
> the car security computer or the car stereo) which draw power all of
> the time.  (I have not measured the Zilla power draw yet.)
>
> In fact... I left my car sitting in my garage unplugged for the last
> 18 days while I was on Christmas vacation just to see what the idle
> power draw was with my DC-DC, car stereo, Zilla, and the original car
> security computers all doing their "car is off" thing.  I can now see
> that my traction pack lost 14% (3.2 kwh) of it's charge sitting around
> for that long.  That is an idle loss of about 180wh per day.  This
> also explains why my 216wh SLI (12V accessory) battery would die in
> one day before I changed my DC-DC converter to be on all of the time.
> (Previously my DC-DC was only on when my car was in "run".)
>
> Back to your original question... Why does the Zilla want to be on all
> of the time?  From the way I understand it, the Zilla has to "boot up"
> when power is connected to it, and that takes 10-20 seconds.  So you
> would not be able to apply power to the Zilla and then immediately
> start your car in the next instant (by shorting the SLI and KEY inputs
> to the Zilla).  You would need a time delay... and since most people
> find a time delay while waiting for their car computer to "boot up"
> unacceptable... it's easier to just leave it on all of the time.
>
>
>