The NC12L12 (shown here) is the standard controller from this family of Controllers.  These controllers are designed for the PV user who require the highest levels of system dependability, lowest battery watering maintenance, Longest life from flooded lead acid and gel battery technologies.   These controllers are in use everywhere between Florida USA, Saudi Arabian Deserts, to Antarctica ( See the Who's Using Flexcharge Link).   With these controllers performing dependably in those locations, you can be assured it will work for you.   As with all Flexcharge controllers The NCxxLxx Controllers are designed using the latest proven surface mount technology components.  Low standby power consumption is achieved in these controllers with a 6mA typical parasitic current.  Each controller is tested for proper operation prior to being placed into its shipping container.

Indicators
The complexity and quantity of status indicators were intentionally kept to a minimum on the NC12L12. The two dual color LEDs smartly show when the batteries are being charged by the green section of the top LED. When the controller is regulating the RED section of the top LED shows RED. When the load is ON the lower LED will glow Green, and when the controller is in Low Voltage Disconnect by the lower LED will glow RED.

Operation
The NCxxLxx use the Flexcharge Charge method described below for superior battery operation.

The circuitry is designed to ignore numerous types of false inputs from stray light sources.

Unlike a number of controllers on the market the NCxxLxx controllers switch power to the Positive Side of the Load and the Battery Charging connections.  This allows the user to connect all the system grounds to one location rather than running a separate wire for PV-, Load- and Battery- to the controller, a feature that is required for UL approval.

One small but convenient feature not found on competitors controllers but is included with the NC12L12 is the Manual Low Voltage Disconnect RESET Circuit. This function is also used to test the load circuitry after the installation is completed, and / or when The Low Battery Disconnect circuitry is active. To activate the RESET circuit pass a small magnet over the RED Low Battery Symbol. The load will also illuminate briefly indicating that the Load Circuitry and Low Battery Voltage Disconnect circuit is functioning properly.

Features

• Waterproof packaging.
• Reverse polarity protected on battery wires.
• Easy to read LED indicators clearly display the controller's status.
• High efficiency charging circuitry.  Insertion Loss resistance of only 0.080 Ohms on 12A Model, 0.008 Ohms on the 30A model.
• Field select for 12V or 24V operation.  Shipped ready for 12V systems, simply cut a wire jumper for 24V
• Order with Load ON at Dusk, OFF at Dawn operation, or Load always ON.
• Low battery voltage Load Disconnect (LVD) and automatic LVD reset at dawn (A SES Flexcharge Patented feature).
• Manual Load Test / LVD Reset magnetically operated switch located under the load status indicator.  Easily reset the LVD circuit after installation and test the controller's load circuitry.
• Delayed Low Battery Disconnect to prevent disconnect during momentarily high load currents.
• Delayed Dawn sensing circuit to prevent load switching during momentarily bright light levels (i.e. Lightning flashes, vehicle lights).
• Small enclosure 3"H x 3"W x 1.5"D + mounting feet.

Options

• Temperature Compensation.
• High current models (NC30L12, NC12L30, & NC30L30) 30 ampere charge and/or load capacities.
• Integral Digital Load Timer.  Use with Dusk to Dawn Model.  Starts timer at dusk then turns the load OFF after the selected time has elapsed. Set Run times up to 7.5 hour in 1/2; hour increments or 15 hours in or 1 hour increments, includes Dawn Override.
• Integral Load Flasher circuitry.  Order flash repeat times from 0.25 sec to 10 sec with ON-Times from 0.1 sec to 5 sec.
• Voltage sense wires allowing the controller to be installed anywhere between the PV panels and the batteries.

The Flexcharge Energy State Taper Charge Process monitors the battery for the full charged resting voltage of the batteries cells. There are tremendous advantages to this charge method.  

• Zero overcharging
• Less need for temperature compensation
• Exceptionally low gassing (Up to 90% less)
• Non-Destructive Micro-Equalization at each full charge
• The battery's chemical processes actually control the charging
• No RFI or EMI emissions to interfere with radio equipment

The Flexcharge method greatly reduces the need for temperature compensation. This occurs because the plate voltage is not constantly held at the critical plate saturation point. Tapering is controlled by the battery's level of charge rather than with timers, or fixed voltages as in PWM and other constant voltage charge methods. The battery takes exactly what it needs rather than being forced to take a set voltage. With the Flexcharge method you can charge your battery bank indefinitely and overcharging will not occur.    The batteries will last longer, require less watering maintenance, and hold a better charge.

As charging begins the controller allows full charging current to pass directly to the battery. When the battery voltage rises slightly above the plate saturation point, the controller opens the charging circuit. Much like a sponge will continue to absorb water towards its center after it has taken it all into its surface, the chemical charging process continues after the charging current has been removed.  As the charge is absorbed the battery's voltage will fall.  When the battery voltage has floated down to approximately 13.5V to 13.8V on a 12 V system,   it is ready to accept another charge pulse. This charge regulation method is actually controlled by the battery's ability to accept and absorb energy. When the battery needs more energy indicated by plate voltage, the controller applies it. Mid way in the charging cycle the controller will cycle ON and then OFF sending full charge current pulses into the plates. A process which charges with very low gassing, and equalizes the plates with each full charge.  As the battery reaches a higher level of charge the amount of time the controller spends in charge is reduced, and the time in rest is increased. At full charge the controller will apply short duration pulses to maintain the battery at an average voltage of about 13.75 volts. This keeps gassing to a minimum while effectively trickle charging, and equalizing at the same time.

There has been allot of discussion over which charge process is better, PWM, or this method.  To add fuel to the fire, each company making "ON-OFF" controllers has chosen different voltages to set the disconnect and reconnect points.  We have seen controllers using a version of this method where the reconnect voltage on a 12V system was set at 12.6V @ 70°F.  On this system the batteries would never see more than 80% charge, and likely much less.  The PWM type controllers will obviously regulate the charging your batteries, and with proper temperature compensation, heat sinks, and the correct Bulk-Regulate-Float (3 stage) algorithm will do a pretty good job of it, but why settle when you can get so much more in a charge regulator.  Instead of three stages with PWM you get an infinitely variable charge process which will supply the battery with exactly what it needs and only when it needs it.  You get less plate saturation gassing, non destructive equalization and Zero EMI as well.