The Sunforce 7 Amp Charge Controller is designed for solar panels that are used to charge 12-volt batteries. When used in conjunction with 12-volt solar panels, the charge controller prevents the batteries from overcharging. It is rated at up to 7 amps of array current and solar electricity of up to 100 watts. The device features two LED light indicators: one to indicate a currently charged battery and one to indicate a fully charged battery. The unit measures 2.5 inches wide x 4 inches high x 1 inch deep and weighs only 1 pound.

Ease-of-use: The Sunforce 7 is simple to use, but it could have been made simpler by equipping it with screw-on terminals for the connecting wires. Instead, it simply has connector wires, and these are not of the best quality. Of course, they are designed for low current use, but stronger connector wires would mean they last longer, especially if the unit is to be moved around.

Another problem with Sunforce 7 is that LED colors and code flashes are nowhere explained in the manual. Steady green means fully charged, but the fast amber blinking, slow amber blinking, and steady amber light could mean just about anything. Otherwise, once they are installed, there is nothing really operate.

Maintenance: The Sunforce 7 stands up well as long as one condition is met: it has some sort of protection from the elements. This unit is not weather-proof. It could become inoperable in precipitation, and it will show signs of wear quickly if left in the open. Water can easily get inside the case where the front and back panels meet. It may require cleaning if left out for long, but these units are so inexpensive, it is not that big a deal. If kept out of the weather, there is no maintenance required except for an occasional dusting.

Functionality: This charge controller does exactly what it claims to do. It keeps 12-volt batteries from becoming overcharged, and it also prevents the charge from leaking out of the batteries during times when no charge is possible, such as at night or on overcast days. Once the unit is connected, it simply works and will work for as long as the circuits remain free of corrosion and damage.

Pros
• Simple to use
• Works as advertised
• Low price

Cons
• Low quality connecting wires
• No screw terminals
• Not weather-proof
• Indecipherable LED codes

Overall Rating:

Description: The Brunton Solar Controller 12v Battery Charging Monitor is an helpful tool to help you avoid overcharging your 12-volt batteries. The manufacturer says that once connected you can charge your 12v battery nonstop for days. The controller will cut off the power when charging is complete.  It’s also good for maintaining the battery in its fully charged state (i.e. RV parked for days or boats). It’s compatible with most of the solar panels (of different brands too) available.

On This Page

• Uses
• What I Liked
• What Needs Improvement
• Where to Buy and Coupons
• Ratings in details
  • Packaging & Design
  • Price
  • Dimensions
  • Usability
• Share Your Thoughts

Uses: Useful for RV, Boats and all batteries that need to stay well charged for long periods of disuse

What I Liked: It’s a normal controller…not so much to say. Brunton is a good brand. The led indicator are helpful to know when the battery is full.

What Needs Improvement: The controller is nearly perfect…great job!

Where to Buy & Coupons: Amazon

Ratings in Details

Package & Design:

Not so impressive but compact and useful

Installation:

The controller is easy to install and provides an indication of “charging” or “charged”.

Price:

Nearly 30 dollar is a good price considering the quality of this tool and cost savings of not having a “fried battery”

Dimensions:

It measures 3.8 x 1 x 2.7 inches; weighs 4.2 ounces.

Usability:

Before you attach it to the battery both the CHARGING and BATTERY FULL light will be on. Once you hook it up to the battery it works well. It looks very standard in its construction. Versatile for every solar panels.

Share Your Thoughts: If you’ve bought the Brunton Solar Controller, tell us what you think.

Note: Comments in the resources section may occasionally be pruned.

Solar charge controllers help in protecting batteries from overcharge and excessive discharge. The controller assures that the battery is charged fully and keeps it that way without causing damage to the battery.

A basic solar charge controller will monitor the battery voltage, open the circuit and then stop charging when the voltage rises to a given level.

Pulse Width Modulation (PWM)

The modern solar charge controllers use pulse width modulation (PWM) which gradually lowers the amount of power as the batteries get closer to being fully charged.

The battery is charged with lesser stress thus prolonging the battery life. PWM has no mechanical connections that need to be broken although it’s quite complex.

Maximum Power Point Tracking (MPPT)

The newer version of solar charge controllers is the Maximum Power Point Tracking (MPPT) that converts excess voltage into amperage. This ensures that the charge voltage is kept at an optimal level while the time needed to completely charge the battery is reduced.

MPPT also helps to reduce power loss and preventing reverse current flow.

Before You Buy

When choosing a solar charge controller there are various factors one should look out for. First is the operating voltage and its rated current. A good solar charge controller should be able to handle the rated current of different panels combined.

The other point of consideration is whether an indicator is required (to show how the charge controller and the solar panel are working) or a meter which will display the charging current and battery voltage.

Some Suggestions

Morningstar solar Charge Controllers are made to specifically meet the needs of the rural solar home systems especially in the developing countries. General features of this product include accurate voltage and current display, weatherproof, longer battery life and remote temperature sensor. “It’s cheap and reliable” says Brian from Austin (September 12, 2008).

Blue Sky solar Charge Controllers are MPPT type photovoltaic controllers which can serve as 20 amp load controller, they have an automatic /manual equalize function to offer periodic condition flooded lead-acid batteries. “They are cost effective” commented D. Muirhead (Jamaica) on June 8, 2009.

Shunt-mode Solar Charge Controllers use the MPPT technology where a series of regulators are used to control the charging current by interrupting the current flow to the battery when the voltage reaches a certain preset level. The solar panel is connected permanently to a battery through a series diode. Features of this charge controller include battery capacity of 0.1 to 50 Amps hours, solar short circuit current of 0-1 Amp.

The battery is the main component of your power station. Monitoring means knowing the state of charge in your battery. You can choose a voltmeter or use a purpose built monitoring system.

Using a 12 volt battery full of charge let’s say … 120 amp/hours.

If we measure the voltage of fully charged 12 volt battery with nothing connected it should be around 12.6 volts.

If we connect a reasonable load to the battery the voltage will drop to around 12.1 but the battery is still full of charge at this point.

If we connect a charging source to the battery, for example an 80 watt solar panel, the voltage will rise to about 15 – 16 volts.

If the battery was flat we might see the following:

• No load: 12 volts
• With load: 11.0 volts
• Charge connected: 13 volts