I have a 2008 impala with what i think is a parasitic drain. i replaced the battery and it started perfectly for several months. My son stopped driving it when school was cancelled and now if we dont run it for 15 min every 3-4 days it needs to be jumped. I charged the battery and connected my DMM between the neg battery terminal and the cable. With nothing on, there is a 80 mA discharge constantly. If i remove the 10A fuse labeled “DISPLAY”, the current drops to 3 mA. I have tried to find schematics to further troubleshoot but have had no luck. Any suggestions?

thanks!

 

80mA is nothing, thats 0.08A, just shy of a Watt. A small car battery would have an Amp Hour rating of around 50Ah. If fully charged it should be able to sustain that load for approx 600hrs (about a month) before going completely flat. Are you sure its 80mA and not 800mA (0.8A) that would flatten a 50Ah battery in approx 60hrs, putting it right around your 3-4 day range.