Flex max settings

seantseant Registered Users Posts: 9 ✭✭
I recently purchased the flex max 80 and 8 rolls surette 487 amp batteries

Ive set the bulk/absorption at 30.30
float at 27.60
and EQ at 31.2

 What would I set the absorb time limit, end amps and rebuild voltage at.?
I didn’t have those options on my last CC.  

Thanks for the help 


  • 706jim706jim Solar Expert Posts: 484 ✭✭✭✭
    I'm getting the same controller but don't have it yet. However, I've had good luck charging my 8 L16's at 29.8 bulk 27.6 float and equalize at 31.0. My old C40 does two hours equalize not sure about the bulk holding time but probably an hour.
    Island cottage solar system with 2500 watts of panels, 1kw facing southeast 1.3kw facing southwest 170watt ancient Arco's facing south. All panels in parallel for a 24 volt system. Trace DR1524 MSW inverter, Outback Flexmax 80 MPPT charge controller 8 Trojan L16's. Insignia 11.5 cubic foot electric fridge. My 29th year.
  • Dave AngeliniDave Angelini Solar Expert Posts: 6,226 ✭✭✭✭✭
    Look up specs for your battery on the Surrette site. Typically end amps are 1 to 2 % of battery 20 hour AH rate. Surrettes want about 3 to 5 hours but you need to check the spec. A dealer should have given you a cut sheet that has all of this. Re-bulk is a double edged sword. It means that your loads are taking too much priority over charging the battery. Probably from clouds or not enough solar charge current. Charging more than once a day is not a good situation and often means poor design.

    The goal to is charge the battery as fast as possible without exceeding battery spec in good solar weather. This way you will have a better chance of completing charge in winter, if you are offgrid. Measurement of SG will help you dial in the system.
    "we go where power lines don't" Sierra Nevada mountain area
    E-mail [email protected]

  • seantseant Registered Users Posts: 9 ✭✭
    I looked it up on the surrete site.  It was all foreign to me. Lol.  The EQ, float and bulk all came from Rolls
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