Questions about transition Bulk > Absorb and Absorb > Float

Started by openplanet, October 16, 2018, 03:48:45 PM

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openplanet

I understand that with a Classic controller, Whizbang Jr., and flooded lead-acid batteries:

1. As Bulk charging proceeds, battery voltage increases, until...
2. the battery voltage reaches the Absorb voltage setpoint, at which point...
3. the charging stage transitions to Absorb, voltage is held at that setpoint, and...
4. charging current decreases until it falls below the End Amps setpoint, at which point...
5. the charging stage transitions to Float.

I have three questions:

1. The rule of thumb for setting End Amps is 2% of the bank's c/20 rate.  In my case, with a 48 volt bank of 8, 6 volt, 370 ah batteries, this would be around 7.4 amps.  But the actual behavior of my system is that Absorb amps level off around 10.5 amps, at which point the battery temp starts to rise.  So I've set End Amps at 11.  What does this behavior tell me about the health (or sickness!) of my batteries?

2. How much time does the Bulk charging voltage need to be at or above the Absorb setpoint in order for the charge phase to transition to Absorb?

3.  How long does Absorb amps need to be below the End Amps setpoint in order for the charge phase to transision to Float?

Thank you.
_______________________________________
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[And yes,] there is grandeur in this view of life.
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ClassicCrazy

system 1
Classic 150 , 5s3p  Kyocera 135watt , 12s Soneil 2v 540amp lead crystal for 24v pack , Outback 3524 inverter
system 2
 5s 135w Kyocero , 3s3p 270w Kyocera  to Classic 150 ,   8s Kyocera 225w to Hawkes Bay Jakiper 48v 15kwh LiFePO4 , Outback VFX 3648 inverter
system 3
KID / Brat portable