This setting sets the absorption voltage.
Adaptive absorption time
This setting enables or disables the adaptive absorption time.
•
When disabled:
The length of the absorption stage is the same each day, the length is determined by the "Maximum
absorption time" setting, provided there is enough solar power.
Be aware that this option can potentially result in overcharging your batteries, especially for lead batteries and if only shallow
daily discharges take place. Check with the battery manufacturer for the recommended maximum absorption time.
The only condition that can end the absorption time before the maximum time has been reached, is the "tail current" setting. If
the absorption time always needs to be the same length, then disable the "Tail current" setting. See more information on the tail
current setting further down in this chapter.
•
When enabled:
The length of the absorption stage is different each day, it adapts itself to the state of charge of the battery in
morning at the beginning of the charge cycle.
The maximum "adaptive" absorption time for the day is determined by the battery voltage as measured just before the solar
charger begins operation each morning.
12V system
24V system
48V system
Multiplier
Adaptive absorption time
*
Vbatt < 11.9V
Vbatt < 23.8
Vbatt < 47.6
x 1
6:00 hours
11.9V < Vbatt <
12.2V
23.8 < Vbatt < 12.2V
23.8V < Vbatt <
12.2V
x 2/3
4:00 hours
12.2V < Vbatt <
12.6V
24.2V < Vbatt <
25.2V
48.8V < Vbatt <
50.4V
x 1/3
2:00 hours
Vbatt > 12.6V
Vbatt > 25.2V
Vbatt > 50.4
x 1/6
1:00 hour
*) The adaptive absorption time is calculated by the multiplier times the "Maximum absorption time" setting. The adaptive
absorption times in this table are based on the 6 hour default "Maximum absorption time" setting.
Maximum absorption time
This setting sets the absorption time limit. This setting is only available when programming a custom charge profile.
Enter the maximum time in hours and minutes (hh:mm) the solar charger is allowed to spend in the absorption stage. The
maximum time that can be set is 12 hours and 59 minutes.
Float voltage
This setting sets the float voltage.
Re-bulk voltage offset
Sets the re-bulk voltage offset. This offset voltage is used to determine when the float stage stops and the bulk stage starts again,
i.e. the charge cycle resets and starts at first charge stage again.
An example: If the re-bulk offset is set at 0.1V and the float voltage at 13.8 V, the charge cycle will restart once the battery voltage
drops below 13.7V (13.8 minus 0.1) for one minute.
Equalization voltage
This setting set the equalization voltage.
Equalization current percentage
This setting sets the percentage of the "maximum charge current" setting that will be used to calculate the equalization charge
current.
For example: If the "maximum charge current" setting is set at 50A and the "Equalization current percentage" setting is set to
10%, the Equalization current will be 5A (10% of 50).
Automatic equalization
This setting sets the repeat interval when the equalization stage should take place. This can be set between 1 and 250 days.
Setting to 1 means a daily equalization, 2 means every other day and so on.
An equalization stage is typically used to balance the cells and also to prevent stratification of the electrolyte in flooded lead acid
batteries. If equalization is needed or not depends on the type of battery if (automatic) equalization is needed and under what
conditions. Check with the battery supplier to find out if equalization is needed for the battery.
During the equalization stage, the charge voltage increases up to the set "Equalization voltage". This is maintained as long as the
charge current stays below the "equalization current percentage" setting of the "Maximum current" setting.
Duration of the Automatic equalization cycle:
MPPT solar charger manual
Page 21
Configuration and settings
