I have a pc680 battery I may have ruined by not keeping it charged properly, used as a standby battery in a not yet flying 10. Charged it sporadically but apparently with standby power to efis had dropped voltage to a point of doing something internally to the battery since it got from not providing adequate voltage to not charging and holding voltage. Trying some steps to recover this one but brings to question the proper charging voltages for the 680 or 925. From what I read Odyssey says 14.2 to 14.7 volts on alternator, but for storing says 12.84 is full charge so I?m assuming a trickle charge to keep it up to 12.84 is what keeps these batteries going while not yet flying? Anyone been able to recover a fairly new discharged odyssey battery?