Friday, June 28, 2013

Charge profiles - Need help in setting the Default ones...

A new feature of the standalone regulator is built in charge profiles selectable via the DIP switches.  There are 8 positions which can be chosen.  Each charge profiles contains parameters for a series of 'stages' with items such as :
  • Limits to Battery Voltage
  • Limits to Alternator Current
  • Exit criteria to allow moving to next stage based on Time, Current, or perhaps battery voltage.
  • Battery charastics, specifically Temperature compensation
Below is what I currently have for a 'place holder', and am open to input on the profiles as to be honest - mode are largely blank...  So, is there perhaps another battery that should be added?  (ala LiPro).  Should one or two of the spaces be held over for 'future expansion' in the default profiles?  Send me Emails (or post comments here) I would kind of like to have a 'standard' set of profiles and keep them for all revisions to the source, as I really do not want to get into a massive mixture of different source configurations in the field...


Normalized Charge profiles:

Before getting to the actual profiles, we need to understand how the regulator auto-adjusted for different battery voltages.  (12, 24, 36, or 48v).  To avoid making 8 profiles for each battery voltage, I decided to make all profiles  'normalized' to a representative 12v system small (500Ah) battery.   Then at startup the regulator will make two adjustments to the working charge profile depending on:
  1. Sensed Battery voltage.
  2. User selected 'battery capacity size' on the DIP switches.

The sensed battery voltage is applied to target Voltages (increasing them) while the Battery Capacity Size DIP switches are used to increase target Amps.

Example - currently the 1st charge profile entry for  Bulk/Absorption phase has the target VBat defined as 14.1v, and the 'exit' criteria (for exiting Absorption phase when the battery is truly fully charged)  is at 10a  (2% of the 500Ah battery capacity).  Two examples:  First a 12v large battery system then  a 48v mid-sized battery:



12v 1,600Ah battery:
  • Auto-sensing system voltage = 12v, multiplier is 1x.
  • User selected DIP switches  = On-On (1,500Ah or greater battery)
The regulator will adjust the run-time charge profiles as:
  • Volts  * 1x  - based on sensed battery voltage
  • Amps * 4x  - based on user selected DIP switch

So, the 14.1v / 10A  becomes -->  14.1v, 40A  Meaning the regulator will drive BULK mode until the battery voltage reaches 14.1v, then switch to ACCEPT mode - holding VBat at 14.1v until the measured current drops below 40A at which time it will move to the next phase (float in the case).



48v,  800Ah battery bank
  • Auto-sensing system voltage =  48v, multiplier is 4x.
  • User selected DIP switches  = Off-On (500Ah - 1,000Ah battery)
The regulator will adjust the run-time charge profiles as:
  • Volts  * 4x  - based on sensed battery voltage
  • Amps * 2x  - based on user selected DIP switch

So, the 14.1v / 10A  becomes -->  56.4v, 20A  Meaning the regulator will drive BULK mode until the battery voltage reaches 56.4v, then switch to ACCEPT mode - holding VBat at 56.4v until the measured current drops below 20A at which time it will move to the next phase (float in the case).




Charge Profile States:

Each charge profile has the following basic 'stages' or modes:
  • Ramping   - Initial state where the alternator is brought online slowly
  • Bulk         - Regulator will be in Bulk mode until the battery voltage reaches the Accept voltage limit.  During Bulk phase, Amps are limited by the capability of the alternator or optionally a defined max Amps.
  • Acceptance - Voltage is regulated to the defined limit.  Will stay in Accept  until Amps drops below the defined value (indicating the battery is fully charges), or a defined time limit is exceeded.
  • Float           - After Acceptance, this is a 'keeper' stage where the volts are regulated to a lower setting.

Each of these stages or modes have criteria for regulation of Battery Voltage and Alternator Amps, they also have exit criteria (exiting that mode and moving on to the next one) based on time, volts and/or amps being delivered.   There are also some additional stages:
  • Over Charge  - Between Acceptance and Float to give a final 'kick' to some battery types
  • Post Float      - Alternator is turned off letting the battery rest rest
  • Equalize         - Selected overcharging to rebalance the batteries



Charge Profiles:

Each Charge Profile (there are 8 of them, selectable via the DIP switches) has a series of entries to allow for targets and exit criteria, as defined by this structure:  You might find it easier to copy and paste this structure into a text editor of your own, to better be able to read the long lines.  Use a fixed-space font (e.g. Courier) to preserve tabbing and alignment.




//----- This structure defines a 'profile' for battery charging.  Each stage consist of 'modes', primarily:  Bulk, Acceptance, 
// Overcharge, and Float.  Each mode has a max voltage set point, and criteria for exiting that phase (Exceeding a time limit, 
// or Amps dropping below a given value).  Of special note is the entry Float and Post Float, which have additional criteria 
// resuming charging.
//


ACPT_BAT_V_SETPOINT;            // Set point for Ramp, Bulk and Acceptance battery voltage.  

                                // Alternator will transition from BULK mode into Accept Mode when this voltage is reached, and then start the Accept Duration counter.
EXIT_ACPT_DURATION;             // Stay in Accept mode no longer then duration in Hours
EXIT_ACPT_AMPS;                 // If Amps being delivered falls to this level or below, exit Accept mode and go to next (Overcharge)
                                //     Set ExitAcptAmps = 0 to disable Amps based transition and only rely on timeout duration.



                                // Overcharge mode is sometimes used with AGM batteries and occurs between Acceptance and Float phase.  

OC_BAT_V_SETPOINT;              //    Set point for Over Charge battery voltage (Set this = 0 to disable)
EXIT_OC_DURATION;               //    Over Charge mode duration in Hours.  (Set this = 0 will also disable Over Charge step.)
EXIT_OC_AMPS;                   // If Amps being delivered falls to this level or below, system will exit Overcharge mode and go to Float
                                //     Set this = 0 to disable Amps based transition and only rely on timeout duration.



FLOAT_BAT_V_SETPOINT;           // Set point for Float battery voltage

EXIT_FLOAT_DURATION;            // Alternator will stay in Float mode this many hours before entering Post-Float (no charging) mode.  Set = 0 disable transition to Post-float mode.
FLOAT_TO_BULK_AMPS;             // If Amps being delivered exceeds this value, we will assume a LARGE load has been placed on the battery and we need to re-enter
                                // BULK phase.   Set this = 0 to disable re-entering BULK phase feature



EXIT_PF_DURATION;               // Only stay in Post_float mode (no charging) this amount of time.  Set = 0 to disable times based Post-float exiting and exit only on Voltage.

PF_TO_FLOAT_VOLTS;              // If during Post-Float mode VBat drops below this voltage, re-enter FLOAT mode.   
                                // Set = 0.0 to disable exit post post-float mode reverting to FLOAT Charge mode based on voltage.
                                // Config note:  If you configure the system to enter post-float mode from float-mode (by setting the time value EXIT_FLOAT_DURATION), AND you
                                // set both EXIT_PT_DURATION and PF_TO_FLOAT_VOLTS = 0, the regulator will in effect turn off the alternator once charging is completed
                                // and not restart a charge cycle until powered down and up again.  This can be useful if you truly want a one-time only charge.
                                // You could also config the FEATURE-OUT port to indicate the complete charge cycle has finished, to say power-off the driving engine?



EQUAL_BAT_V_SETPOINT;           // If Equalize mode is selected, this is the target voltage.  Set = 0 to prevent user from entering Equalization mode.

EQUAL_BAT_A_SETPOINT;           // During equalization, system will limit Amps to this value.   Set = 0 will also prevent user from entering Equalization mode.
EXIT_EQUAL_DURATION;            // Regulator will not stay in Equalization any longer then this (in Hours).  If set = 0, then Equalization mode will be disabled.
EXIT_EQUAL_AMPS;                // If Amps fall below this value during Equalization, exit equalization.     Set = 0 to disable exit by Amps and use only time.



BAT_TEMP_1F_COMP;               // Battery Temperature is compensated by this factor for every 1F temp change.  Note this is based off of BAT_TEMP_NOMINAL (77f)

MIN_TEMP_COMP_LIMIT;            // If battery temperature falls below this value (in deg-F), cap temp compensation voltage rise to prevent overvoltage in very very cold places.
BAT_MAX_CHARGE_TEMP;            // If Battery exceeds this temp (in deg-f), stop charging and force into Float Mode to protect it from over-temperature damage.






Do I need some additional parameters?  e.g., should there be a Float-to-Bulk voltage set point in addition to the Amps value?




Charge Profile Entries:


And here is the 8 entry table that I have for the current 'charge profiles':  Take note that there are a LOT of blanks, for example Post Float and OverCharge are currently disabled for all entries.  And the Temp Compensation is all set to the FLA type battery, which I suspect is not the right answer.   So - -   If you have knowledge on this area, please send me comments to:  mvVikingStar@gmail.com  Thanks!


   Bulk/Accpt                Overcharge              Float                 Post Float            Equalization                Temp Comp   
{14.1v, 4.5hr, 10a           0.0v, 0hr, 0a          13.1v, 0hr, 0a            0hr, 0.0v,           0.0v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Default (safe) profile.
{14.6v, 4.5hr, 10a           0.0v, 0hr, 0a          13.4v, 0hr, 0a            0hr, 0.0v,         15.5v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Standard FLA
{14.1v, 4.5hr, 10a           0.0v, 0hr, 0a          13.6v, 0hr, 0a            0hr, 0.0v,         13.6v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Standard Gell Cell
{14.3v, 4.5hr, 10a           0.0v, 0hr, 0a          13.1v, 0hr, 0a            0hr, 0.0v,         15.5v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Standard AGM (1)
{14.5v, 4.5hr, 10a           0.0v, 0hr, 0a          13.5v, 0hr, 0a            0hr, 0.0v,         14.5v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Standard AGM (2)
{14.1v, 4.5hr, 10a           0.0v, 0hr, 0a          13.1v, 0hr, 0a            0hr, 0.0v,           0.0v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Reserved for future use??
{14.1v, 4.5hr, 10a           0.0v, 0hr, 0a          13.1v, 0hr, 0a            0hr, 0.0v,           0.0v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}, // Custom #1 - Users Entry
{14.1v, 4.5hr, 10a           0.0v, 0hr, 0a          13.1v, 0hr, 0a            0hr, 0.0v,           0.0v, 0a, 0hr, 0a,         0.028*6/10, 15f, 125f}  // Custom #2 - Users Entry





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