I just installed a brand new battery and plugged it into my Schumacher battery maintainer at the low current setting (3A) until it reached 100%. That was yesterday. I left the car locked in the garage until today. Today I went to check on the car and discovered the battery voltage was 12.6V and my battery maintainer said it was at 77%. So somehow it had lost 23% of charge overnight while parked and locked (so it would go to deep sleep). So then I took it for a drive and did 3 miles. When I got back, I tested the battery again and now it was at 12.4V and 59% charge. That seems excessive, right? Can somebody please let me know if any of this is normal? I have take the car to the dealer and they were no help whatsoever and told me the car was working fine.