Pulse width modulation (PWM)
Pulse-width modulation (PWM), the regulator has a direct connection between the solar panel and the battery and uses a "quick-switch" mechanism to regulate the charge flowing into the battery. The switch remains fully on until the battery reaches an absorbing voltage, at which point the switch begins to turn on and off hundreds of times per second to reduce the current while keeping the voltage constant.
In theory, this type of connection reduces the effectiveness of the solar panel because the voltage of the panel is lowered to match that of the battery. However, in the case of portable camping solar panels, the practical effect is minimal, as in most cases the maximum voltage of the panel is only around 18V (and decreases as the panel heats up), while the battery voltage is typically located between 12-13V (AGM) or 13-14.5V (lithium).
Despite the small efficiency loss, PWM regulators are generally considered a better choice for pairing with portable solar panels. Compared to their MPPT counterparts, PWM regulators have the benefit of being lighter weight and more reliable, which is a key consideration when camping for long periods or in remote areas where repairs may not be easy to make and replacement regulators may be difficult to find.
Maximum Power Point Tracking (MPPT)
The MPPT is tracked by the maximum power point and the regulator has the ability to convert excess voltage into additional current under the right conditions.
An MPPT controller will constantly monitor the voltage of the panel, which changes based on factors such as panel heat, weather conditions and the position of the sun. It uses the full voltage of the panel to calculate (track) the best combination of voltage and current, and then reduces the voltage to match the charging voltage of the battery, which can provide additional current to the battery (remember power = voltage × current).
But there is an important caveat that degrades the practical effects of MPPT controllers for portable solar panels. To get any real benefit from the MPPT controller, the voltage of the panel should be at least 4-5 volts higher than the charging voltage of the battery. Given that most portable solar panels have a maximum voltage of about 18-20V, which may drop to 15-17V when they heat up, while most AGM batteries are between 12-13V and most lithium batteries are between 13-14.5V, the voltage difference is not large enough for MPPT functionality to have a practical impact on charging currents.
Compared with PWM controller, MPPT controller has the disadvantage of heavy weight and poor reliability in general. For this reason, and because they have minimal impact on the power input, you won't often see them used in solar folding packs.
How do portable solar panels actually generate electricity?
Portable solar panels work by capturing sunlight and converting it into useful electricity through a device called a charge controller or regulator. The controller is then connected to the battery to keep it charged.
What is a solar regulator?
The solar regulator ensures that the electricity generated by the solar panels is intelligently transferred to the battery in a way that is appropriate for the battery chemistry and charging level.
A good regulator will have a multi-stage charging algorithm (usually five or six stages) and offer different procedures for different types of batteries. Modern, high-quality regulators will include specific procedures for lithium batteries, while many older or cheaper models will be limited to AGM, Gel and Wet batteries. It is important that you use the correct procedure for your battery type.
A quality Solar regulator and Solar Connector will include a large number of electronic protection circuits to protect the battery, including reverse polarity protection, short circuit protection, reverse current protection, overcharge protection, instantaneous overvoltage protection and over temperature protection.
Type of solar regulator
There are two main types of solar regulators available for portable solar panels. Pulse width modulation (PWM) and maximum power point tracking (MPPT). They all have their advantages and disadvantages, which means that each is suitable for different camping situations.
Pulse width modulation (PWM)
Pulse-width modulation (PWM), the regulator has a direct connection between the solar panel and the battery and uses a "quick-switch" mechanism to regulate the charge flowing into the battery. The switch remains fully on until the battery reaches an absorbing voltage, at which point the switch begins to turn on and off hundreds of times per second to reduce the current while keeping the voltage constant.
In theory, this type of connection reduces the effectiveness of the solar panel because the voltage of the panel is lowered to match that of the battery. However, in the case of portable camping solar panels, the practical effect is minimal, as in most cases the maximum voltage of the panel is only around 18V (and decreases as the panel heats up), while the battery voltage is typically located between 12-13V (AGM) or 13-14.5V (lithium).
Despite the small efficiency loss, PWM regulators are generally considered a better choice for pairing with portable solar panels. Compared to their MPPT counterparts, PWM regulators have the benefit of being lighter weight and more reliable, which is a key consideration when camping for long periods or in remote areas where repairs may not be easy to make and replacement regulators may be difficult to find.
Maximum Power Point Tracking (MPPT)
The MPPT is tracked by the maximum power point and the regulator has the ability to convert excess voltage into additional current under the right conditions.
An MPPT controller will constantly monitor the voltage of the panel, which changes based on factors such as panel heat, weather conditions and the position of the sun. It uses the full voltage of the panel to calculate (track) the best combination of voltage and current, and then reduces the voltage to match the charging voltage of the battery, which can provide additional current to the battery (remember power = voltage × current).
But there is an important caveat that degrades the practical effects of MPPT controllers for portable solar panels. To get any real benefit from the MPPT controller, the voltage of the panel should be at least 4-5 volts higher than the charging voltage of the battery. Given that most portable solar panels have a maximum voltage of about 18-20V, which may drop to 15-17V when they heat up, while most AGM batteries are between 12-13V and most lithium batteries are between 13-14.5V, the voltage difference is not large enough for MPPT functionality to have a practical impact on charging currents.
Compared with PWM controller, MPPT controller has the disadvantage of heavy weight and poor reliability in general. For this reason, and because they have minimal impact on the power input, you won't often see them used in solar folding packs.
Pulse width modulation (PWM)
Pulse-width modulation (PWM), the regulator has a direct connection between the solar panel and the battery and uses a "quick-switch" mechanism to regulate the charge flowing into the battery. The switch remains fully on until the battery reaches an absorbing voltage, at which point the switch begins to turn on and off hundreds of times per second to reduce the current while keeping the voltage constant.
In theory, this type of connection reduces the effectiveness of the solar panel because the voltage of the panel is lowered to match that of the battery. However, in the case of portable camping solar panels, the practical effect is minimal, as in most cases the maximum voltage of the panel is only around 18V (and decreases as the panel heats up), while the battery voltage is typically located between 12-13V (AGM) or 13-14.5V (lithium).
Despite the small efficiency loss, PWM regulators are generally considered a better choice for pairing with portable solar panels. Compared to their MPPT counterparts, PWM regulators have the benefit of being lighter weight and more reliable, which is a key consideration when camping for long periods or in remote areas where repairs may not be easy to make and replacement regulators may be difficult to find.
Maximum Power Point Tracking (MPPT)
The MPPT is tracked by the maximum power point and the regulator has the ability to convert excess voltage into additional current under the right conditions.
An MPPT controller will constantly monitor the voltage of the panel, which changes based on factors such as panel heat, weather conditions and the position of the sun. It uses the full voltage of the panel to calculate (track) the best combination of voltage and current, and then reduces the voltage to match the charging voltage of the battery, which can provide additional current to the battery (remember power = voltage × current).
But there is an important caveat that degrades the practical effects of MPPT controllers for portable solar panels. To get any real benefit from the MPPT controller, the voltage of the panel should be at least 4-5 volts higher than the charging voltage of the battery. Given that most portable solar panels have a maximum voltage of about 18-20V, which may drop to 15-17V when they heat up, while most AGM batteries are between 12-13V and most lithium batteries are between 13-14.5V, the voltage difference is not large enough for MPPT functionality to have a practical impact on charging currents.
Compared with PWM controller, MPPT controller has the disadvantage of heavy weight and poor reliability in general. For this reason, and because they have minimal impact on the power input, you won't often see them used in solar folding packs.