curryinahurry 38 Report post Posted July 26, 2009 Hi guys, Was wondering if anyone knows roughly what the correct current draw from the battery when the car is off? I've been having to jump start my car every morning, but before I replace the battery, I want to make sure that its not something else... Measuring with an ammeter, I got roughly. 0.15mA - Does this sound normal? - By pulling out all the fuses, I found that 0.1mA is from the "cabin". This is a 91 Subbie Leggy. Be great if someone could let me know whats the normal current draw! Cheers, Andrew. Quote Share this post Link to post Share on other sites
hotwire 352 Report post Posted July 26, 2009 .15 is a little high but hardly over the top - is there an alarm in the equation? Usually "normal" anywhere between .02 & .06 How long are you checking for? Key illumination? if so are you allowing time for this to go off? .15 is only a tenth higher & with normal car use - this wouldn't be an issue. Doesn't point to a bulb on or alt issue as current draw would be higher Quote Share this post Link to post Share on other sites
2002 1 Report post Posted July 26, 2009 Measuring with an ammeter, I got roughly. 0.15mA - Does this sound normal? - By pulling out all the fuses, I found that 0.1mA is from the "cabin". To put it in contex. I assume that your car has battery rated around 90 A-hr. This implies a fully charged battery should be able to supply 0.15 mA for 90/0.15 e-3 hrs or 600000 hours or 68 years. ( self discharge in the battery will be more) Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted July 26, 2009 (edited) It doesnt work like that though. You need amperage to work the starter motor without the control units loosing voltage as well, current draw from the starter is higher in colder climates and in winter. Most control units need a minimum of 10 volts to operate properly. TIS states a maximum of .02 mA for current draw in sleep mode. Edited July 26, 2009 by *Glenn* Quote Share this post Link to post Share on other sites
2002 1 Report post Posted July 27, 2009 Agreed but the point I was making was that fractions of milliamps are insignficant compared to the storage capacity of a fully charged battery. Now if the leakage current was in the amp range..... Quote Share this post Link to post Share on other sites
curryinahurry 38 Report post Posted July 27, 2009 Hey guys, thanks heaps for all the information! I'll pop the fuse out tomorrow and see if it helps, but I think I'll get a new battery this weekend anyway. Cheers! Quote Share this post Link to post Share on other sites
