Re: [Amel Yacht Owners] Re: Batteries
"3.7 Battery charging information The charge controller starts a new charge cycle every morning, when the sun starts shining. Default setting: The maximum duration of the absorption period is determined by the battery voltage measured just before the solar charger starts up in the morning: Battery voltage Vb (@start-up) Maximum absorption time Vb < 23,8V 6h 23,8V < Vb < 24,4V 4h 24,4V < Vb < 25,2V 2h Vb > 25,2V 1h (divide voltages by 2 for a 12V system) If the absorption period is interrupted due to a cloud or due to a power hungry load, the absorption process will resume when absorption voltage is reached again later on the day, until the absorption period has been completed. The absorption period also ends when the output current of the solar charger drops to less than 2Amps, not because of low solar array output but because the battery is fully charged (tail current cut off). This algorithm prevents over charge of the battery due to daily absorption charging."
From my Victron MMPT manual, page 10. It is in most of the current Victron MMPT manuals, e.g. https://www.victronenergy.com/upload/documents/Manual-BlueSolar-charge-controller-MPPT-100-30---100-50-EN-NL-FR-DE-ES-SE-ul.pdf