Windy Nation TrakMax 40 MPPT Solar Charge Controller - Manual (Page 14)

TrakMax 40 User Manual
Revision 1.0
4.2.2 Three Stage Charge
The TrakMax is configured for a three stage charging process, Bulk, Absorption and Float. The three stage
charge process provides a somewhat higher charge voltage to charge the battery quickly and safely. Once
the battery is fully charged a somewhat lower voltage is applied to maintain the battery in a fully charged
state without excessive water loss. The three stage charge process charges the battery as quickly as
possible while minimizing battery water loss and maintenance.
4.2.2.1 Bulk Stage
When charge starts the TrakMax attempts to apply the bulk charge voltage to the battery. The system will
switch to Bulk charge if the battery is sufficiently discharged and/or insufficient charge current is available to
drive the battery up to the bulk voltage set point.
During this stage, the batteries are charged at the bulk voltage setting. And the unit delivers as much charge
current as possible to rapidly recharge the batteries. When the battery voltage reaches the bulk voltage
setting, the charge controller activates the next stage (absorption). TrakMax will again switch to Bulk charge
if battery voltage drops below the present charge voltage set point.
4.2.2.2 Absorption Stage
During this stage, the unit changes to a constant voltage mode where the absorption voltage is applied to the
battery. When charge current decreases to the float transition current setting, the battery is fully charged and
the unit switches to the float stage.
4.2.2.3 Float Stage
During this stage, the float voltage is applied to the battery to maintain it in a fully charged state. When
battery voltage drops below the float setting for a cumulative period, a new bulk cycle will be triggered.
4.2.3 Equalization
Equalize charging is a special mode of battery charging. During use, the battery’s cells can become unequal
in the voltage and current they can deliver. This is due to a buildup of sulfate on the plates as well as
stratified electrolyte. Sulfate prevents the cells from receiving or delivering full power. If the sulfate is left on
the plates, it will harden, and permanently reduce the battery’s capacity. Stratification separates the heavier
acid from the water, and the concentrated acid remains at the lower portion of the plates, eventually
corroding them. Equalizing the batteries every month or two (depending on usage) prolongs the life of the
batteries and provides better battery performance.
To set the Equalize Charge:
1) Remove all DC loads connected to the batteries.
2) Remove all battery vent caps.
3) Check the battery water level; it should be just over the top of the plates (do not over fill). Use only
distilled water for filling batteries.
4) Set the BATTERY TYPE SELECTOR switch to position “0” or “1”.
Page 14 of 20 windy nation 03/06/2013