Purchase Solar Charge Controllers
WHAT ARE SOLAR CHARGE CONTROLLERS?
Charge controllers are the main units in a solar system while they prevent overcharging of batteries and increase the lifespan of the total system. We offer simple charge controllers which stop charging the battery when they exceed a preset voltage level in addition to more sophisticated MPPT (Maximum Power Point Tracker) controllers which optimize the maximum power charge for the batteries by tracking and optimizing the voltage and current level.
A charge controller, or charge regulator is similar to the voltage regulator in your car. It regulates the voltage and current coming from the solar panels going to the battery. Most "12 volt" panels put out about 16 to 20 volts, so if there is no regulation the batteries will be damaged from overcharging. Most batteries need around 14 to 14.5 volts to get fully charged.
DO I ALWAYS NEED A CHARGE CONTROLLER?
Not always, but usually. Generally, there is no need for a charge controller with the small maintenance, or trickle charge panels, such as the 1 to 5 watt panels. A rough rule is that if the panel puts out about 2 watts or less for each 50 battery amp-hours, then you don't need one.
For example, a standard flooded golf car battery is around 210 amp-hours. So to keep up a series pair of them (12 volts) just for maintenance or storage, you would want a panel that is around 4.2 watts. The popular 5 watt panels are close enough, and will not need a controller. If you are maintaining AGM deep cycle batteries, such as the Concorde Sun Xtender then you can use a smaller 2 to 2 watt panel.
CHARGE CONTROLLERS COME IN 3 GENERAL TYPES (with some overlap):
1) Simple 1 or 2 stage controls which rely on relays or shunt transistors to control the voltage in one or two steps. These essentially just short or disconnect the solar panel when a certain voltage is reached. For all practical purposes these are dinosaurs, but you still see a few on old systems. Their only real claim to fame is their reliability - they have so few components, there is not much to break.
2) 3-stage and/or PWM are pretty much the industry standard now, but you will occasionally still see some of the older shunt/relay types around, such as in the very cheap systems offered by discounters and mass marketers.
3) Maximum power point tracking (MPPT) are the ultimate in controllers, with prices to match - but with efficiencies in the 94% to 98% range, they can save considerable money on larger systems since they provide 15 to 30% more power to the battery.
Most controllers come with some kind of indicator, either a simple LED, a series of LED's, or digital meters. Some newer ones now have built in computer interfaces for monitoring and control. The simplest usually have only a couple of small LED lamps, which show that you have power and that you are getting some kind of charge. Most of those with meters will show both voltage and the current coming from the panels and the battery voltage. Some also show how much current is being pulled from the LOAD terminals.
Purchase Solar Charge Controllers
Courtesy of www.windsun.com
