You would think so Jake, but not the case.
The O2 heater element draw is non-linear.  The draw starts off high but
drops significantly as the element heats up.
OTOH, the fuel pump has to provide high pressure continuously, and gets my
vote for current hog.

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Jake de Villiers
Sent: Friday, August 21, 2009 11:22 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Engine electrical power requirements?

Our race car had no alternator fitted and would run the starter, fuel pump,
gauges and ignition for 2 practice sessions and a race without needing to be
recharged.

Prolly the biggest consumer would be the oxygen sensor - I can't see the ECU
needing bags of current...