PWM Charge Controllers

A: A solar charge controller is vital to safely and efficiently charge batteries in a photovoltaic system. A charge controller is an electrical device that helps prevent the battery bank from overcharging and over-discharging. It does this by managing the current and voltage that flows to the battery from the solar panel(s) so an Off-Grid solar system can operate efficiently.

Why use a solar charge controller in an Off-Grid solar system design?

A: There are four reasons:

1. A solar charge controller protects the battery investment –

• It allows for optimized battery charging to protect one of the most expensive components in a solar system, the batteries, and ensure this investment is maximized. This device maintains energy production operating in the range where a specific battery brand, technology, application, temperature range, and location works best.
• As such, over-discharging and overcharging are prevented, ensuring optimized battery performance. At the same time, this battery care also guarantees maximized battery bank life and system reliability.
• If done properly, a solar charge controller can effectively reduce wasted time and money by minimizing unnecessary battery replacements and inconvenient downtimes.

2. A solar charge controller prevents wasted energy losses at night because a primary function is to stop reverse current flow to the PV panels during the evening hours.

3. A solar charge controller is typically equipped with display screens or LED indicators that allow easy and convenient monitoring of the solar system’s status. In certain situations, this can also prove useful for troubleshooting.

4. Selecting the right solar charge controller is essential for certain applications requiring advanced features. It ensures reliable, maximum performance and flexibility through useful features such as software or applications, lighting controls, and data logging. The proper solar charge controller will ensure an application’s specific needs are efficiently addressed. All customers can agree, efficiency is one primary key to maximizing incoming energy production for the best return on investment figures.

There are different versions of photovoltaic or PV charge controllers for Off-Grid applications. Phocos offers both Pulse-Width Modulation or PWM controllers and Maximum Power Point or MPPT controllers.

Phocos PWM (pulse-width modulation) charge controllers rapidly connect and disconnect the PV-input directly to the battery output without a voltage conversion.

A: The PWM solar charge controller draws its power from the battery bank. Using it’s pulse width modulation, or PWM circuit, it regulates solar power input into battery charging output to charge a DC battery bank. A PWM solar charge controller does not do DC to DC conversion so system design with compatible PV solar panels and DC batteries is essential.

Sensing and control circuitry continually monitors the battery bank, the environmental conditions and photovoltaic module input, to ensure proper charging.

The DC battery bank supplies power to connected loads, through the solar charge controller’s load switch. Again, sensing and control circuitry continually monitors the battery bank, environmental conditions, and the load current to prevent any situations that could be damaging to the DC battery bank or to the DC loads.

For 20+ years, Phocos has supplied proven, robust PWM and MPPT solar charge controllers.