Almot wrote:
I meant - to get to Bulk/Absorption transition, or Absoprtion voltage, whatever.
Yes, it's better if it not just gets to Abs point, but also completes the prescribed stay at this voltage, timer-based or current-based. In my system it goes to Float very soon after it has reached Abs voltage, timer is seldom triggered, so to me "getting to Abs" and "getting to Float" is almost the same. OP will probably get some PWM, so it will be a little different.
Generally, the State of Charge (SOC) of the battery when you get it to Vabs depends on the charging rate and that voltage. For a fixed voltage, and the same battery size, say 14.4v, the higher the charging current during Bulk, the sooner you will get the battery to that voltage and at a lower SOC.
Lower charging current to get to the same Vabs means you spend more time in Bulk and get to a higher SOC before reaching Vabs. ( That will be slower and longer generator time than if you used a higher charging rate--your tapering amps in Absorption will still be more amps than the lower charging rate amps for a time there, so you are still faster until amps are the same at some SOC up there nearer the end)
So on solar you have low amps and usually a decent sized battery bank, so you will not get to 14.x until your SOC is quite high, probably in the 90s percentage. Meanwhile, your Absorption Stage will usually end at about 97% SOC regardless, and go to Float.
So with a low charging rate like solar does, your "window" to be in Absorption is quite narrow between 90 something when you get to Vabs and 97% when you trigger Float.
However some controllers have no Float to trigger, so they just stay at Vabs until dark once they reach Vabs. Others have a timed Absorption Stage like two hours so they could go past 97% before dropping to Float. Others have adjustable Float and Absorption voltages. If you want a longer Absorption stage, you can make your
Float voltage the same as your Vabs, so it will stay at your Vabs until dark.
