2010 Prius If the car sits for a couple of days I cannot start the car unless I recharge the 12v battery. If I drive the car everyday I have no problem. It seems to me that there is a slow drain on the battery. I have checked to make sure all the lights are off and the doors and rear hatch are properly closed. Any other suggestions?
There is a small parasitic drain; you can measure it by putting digital multimeter in series, between the negative battery cable and car body. Shut the hatch and let everything sit, and monitor milliamperes. In my experience it was around 16~18, with regular spikes to around 40. Not sure what that was, maybe that little security icon on the dash, though it didn't seem to be in sync. Anyway, 2010, original battery? Likely best to change it.
If it was never replaced, you are in luck having such an old vehicle with the original Aux Battery. Replace that "thing" for a brand new one an all the existing electrical problems will disappear
