A Forum run by Enthusiasts of MidNite Solar

Charge Controllers and Clippers => The "KID" charge controller => Topic started by: Rain Dog on May 26, 2015, 05:09:18 PM

Title: Bulk to Absorb to Float
Post by: Rain Dog on May 26, 2015, 05:09:18 PM
How does the KID decide when to switch from Bulk to Absorb? Absorb to Float?

I had 200 Watts of solar connected in parallel to 225 AH of Trojan T-105 batteries. The charge controller was pretty much always in BulkMPPT mode, which is what I expected since we are always between 50% and 80% SOC.

I added another 100 Watts today and switched series. The controller ran in BulkMPPT when I first looked, but a few hours later it was in float.  No way the batteries are over 80% SOC. Trying to understand how it decides what mode to be in to get an idea of what is going on.
Title: Re: Bulk to Absorb to Float
Post by: Doug on May 26, 2015, 05:21:03 PM
Hi Dog,

The charge mode is decided by battery voltage (User adjustable)

On a typical 12V system: (double for 24V)
Bulk - All available power goes to the batteries until they reach the absorb voltage setting, usually around 14.7V.
Absorb - Holds the batteries at the absorb voltage setting, backing off on power as needed for either the times set or by ending amps if using the WBJr.
Float - when Absorb has either timed out or the end amps match their setting if using the Whiz Bang Jr. the batteries are held at the user adjustable Float voltage usually around 13.4 to 13.8 (use battery mfr's recommended settings).
This assumes enough solar is available to complete each mode.

HTH,
Doug
Title: Re: Bulk to Absorb to Float
Post by: ClassicCrazy on May 26, 2015, 05:38:14 PM
Doug explained it perfectly !
Title: Re: Bulk to Absorb to Float
Post by: TomW on May 26, 2015, 07:13:43 PM
Be sure to calibrate the voltages (input and battery) on the Classic via the "tweaks" menu.

Tom
Title: Re: Bulk to Absorb to Float
Post by: Halfcrazy on May 26, 2015, 08:20:23 PM
Also make sure end amps is not set causing it to go to float
Title: Re: Bulk to Absorb to Float
Post by: Rain Dog on May 27, 2015, 03:01:59 PM
Thanks for all the info. I think I have it setup correctly now.