TVM's comment here www.honestjohn.co.uk/forum/post/index.htm?t=44019&...e got me thinking - I wonder how much power a modern car that to all intents and purposes is 'off' is actually drawing from the battery? 
 
                            
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                        Negligble in most cases.  Certainly less than leaving sidelights on.  But it does emphasise the need for better batteries than was the case a few years ago. 
 
                            
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                        Feeds to radio, clock and security systems, can't really think of much else.
                            
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                        Feeds to radio, clock and security systems, can't really think of much else.  
>> 
 
light on in boot?
                            
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                        light on in boot?  
Surely that would only be on if the boot was open? 
Does the ECU need a permanent feed?
                            
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                        Does the ECU need a permanent feed?  
 
Yep, that's why people often say disconnect the battery and leave for 30 mins when a modern car is running badly.
                            
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                        >> light on in boot? >>  Surely that would only be on if the boot was open? Does the ECU need a permanent feed?  
 
sorry :( i put that because someone always says "my battery goes flat overnight" and the light on in boot? is the standard reply.............. 
no it is not normaly on....
                            
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                        It's always a good one to be rid of an annoying, preferably guillable, apprentice for a short while:- 
 
"Climb into the boot, and tell me if the light goes off or not" - Shut the boot, and then go on tea break, or even better, on road test! 
 
Number_Cruncher 
                            
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                        Climate control standby, security systems, radio standby, various ECUs,  
 
With a modern fully can bus operated car, it must be drawing at least 1/2 amp if not more 
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TourVanMan TM   < Ex RF >
                            
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                        This has been on HJ before.  I measured the current drain of one of the new shape Micras.  It was 65 mA (0.065 amps).  It altered to something higher if you went near it with a key.  The key, sort of, 'woke' it up.
                            
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