Cost Effective Solar Options: PWM Technology
A charge controller is essential for every solar power system. You can think of the charge controller as the hardworking “middleman,” continuously and effortlessly regulating the charge flowing between the solar panel(s) and the battery. Renogy Solar sells two kinds of charge controllers that can support several different system sizes: PWM and MPPT. PWM stands for “Pulse Width Modulation,” which is the way the controller regulates the charge flowing to the battery. PWM controllers utilize a pulsing signal to send the perfect amount of charge to the battery. The charge controller continuously checks the battery’s state and self-adjusts the length and speed of each pulse delivered. This technology is similar to many high quality battery chargers: once the charge controller detects certain set-points, it adjusts its charging algorithm accordingly. This prevents the battery from becoming overcharged or discharged. PWM controllers are specifically optimized for use with systems under 400W, as they automatically adjust for battery aging, self-regulate for voltage drop and temperature effects, while at the same time increasing the charge acceptance of the battery. Standard PWM controllers are compatible with flooded and sealed lead acid batteries, but cannot be used with gel batteries.
Much like the PWM controllers discussed above, MPPT, or “Maximum Power Point Tracking” controllers regulate the charge flowing to the battery, but do so more efficiently. Throughout the daylight hours, weather conditions, temperatures, and light levels change. These changes affect the voltage flowing from the solar panel to the battery. MPPT controllers match the voltage levels flowing from the battery and adjust accordingly. An added benefit of MPPT controllers is that they are compatible with flooded and sealed lead acid as well as gel batteries, a less often used alternative.
There are many benefits in choosing either PWM or MPPT controllers; however, when it comes to value, PWM controllers are the better choice. Renogy PWM charge controllers retail for roughly 1/3 the cost of even the most inexpensive MPPT controllers. Though in larger systems an MPPT controller may be more beneficial to increase charging efficiency, for smaller off-grid kits or beginners, PWM controllers provide a basic and cost effective option. Renogy carries a number of different PWM controllers that are designed for use with different system sizes and specific needs.
This month, Renogy is announcing the addition of two new PWM solar charge controllers to its store inventory. Renogy will release the Adventurer and Wanderer (30A) controllers in August of 2015. Both of these new controllers are PWM models, but come with greater protection features and a self-diagnostic system. Unlike the standard 30A PWM controllers currently available, both the Adventurer and Wanderer are compatible with flooded and sealed lead acid batteries, as well as gel batteries. For the most accurate return of capacity, and for the prevention of
excessive gassing pressure, the battery is required to be controlled by specified voltage regulation set points for Absorption, Float, and Equalization charging stages. Both controllers have a 4 stage PWM charging: bulk, boost, float, and equalization. If ease of use is a concern, both controllers contain an interactive LCD display and both are specifically designed for clean mounting on RV interiors. The included temperature sensors measure the controller’s temperature compensation, another feature for safe and effective charging. Adding to the uniqueness of this new controller, it also has a four-stage battery algorithm for rapid, efficient, and safe battery charging. Both controllers come in one standard color and size and are compatible with sealed, flooded, and gel lead acid batteries.
So next time you are looking for a charge controller, visit Renogy-Store.com to shop anytime, anywhere, 24/7. Each product page in the store comes with a comparison diagram, so you can make a side-by-side comparison of the benefits of each controller. If you have any questions, the Renogy tech support staff is standing by to assist.