Battery current loss/starting problem. Recommendations

john545

2015 Civic sedan won't hold full charge and battery has 12.35--12.42V. Has anyone found a fix for this problem? Honda dealer/AMH checks alternator output and battery voltage; finding both "good" but does not find problem cause or solution.

elias

parasitic drain, some interior light is remaining powered when car is parked?
look at the car when it is parked in a pitch dark garage, is light shining from glovebox or is the subwoofer giving an occasional subwoof?

a test to disprove the above idea is to disconnect the battery while it is parked, or use an ammeter.

thecardoc3

Exactly what is the problem? Have you been having trouble starting the car? 12.35v-12.42v is between a 70% to 80% state of charge and that's really where most manufacturers like to keep a battery today. With a slightly lower state of charge the battery easily absorbs any voltage spikes and still has plenty of output which results in a much cleaner system voltage and that reduces the chances for electronic glitches.

john545

Thanks for your information. Will look for drain sources. The car failed to start once and has been OK for over 10 days. I was concerned that 90% of my driving was at around 1400-1500 RPMs and that load, over time, was overcoming charge. Also of concern is starting the car in below freezing weather (local temperatures here rarely get below 20 Deg.)

I have been unable to get Honda to give me the procedures to remove my battery and the procedures for charging and battery removal are not in the manual or the provided CD. Such information is to be withheld and not provided to owners. Interestingly, jump-starting procedures, which can be inherently risky, are provided.