parasitic current draw
I have read where 50 ma parasitic current draw is on the high end. Some examples of accessories with their current draw: Voltage regulator 1 - 2 ma, digital clock 3 - 5 ma, quartz clock 7 ma, ECM 7 - 8 ma, radio & clock 7 ma. and there are other relays and sensors that add more parasitic draw.
After a power door lock relay shorted out, the old Autolite battery was completely discharged on my '91 S10 Blazer within 24 hours. I installed a new ACDelco battery and started using a Deltron 800 ma Battery Tender and the problem was solved. I attach the battery tender every time I park the car in the garage.
Attaching the battery tender every time I park the car in the garage is probably unnecessary if I would drive the vehicle every day or two. The Blazer may sit for two weeks before being driven again so I hook up the battery tender. I have Deltran's optional battery lead attached to the positive and negative battery terminals so it is no trouble to plug in the tender.
Be aware that the ECM in the failure mode can have a high parasitic battery drain that cannot be detected in the conventional manner. When the battery is disconnected the ECM solid state circuit will not show a battery drain until the continuity is restored. Cycling the ignition switch from off to run position may cause the electrical drain to reoccur but do not do that with the amp meter installed in series with the cable and negative battery post.
Last edited by MouseFink; 08-24-2011 at 06:36 AM.