Reading this review guide, will put you in a much better position to select the best solar charge controller suitable for your power system.
What is a Solar Charge Controller?
It can be defined as a device place in between the battery and solar panels, so as to regulate the amount of power flowing in and out of the battery. A controller comes in handy for all types of power sources including PV, hydro, wind fuel and utility grid. To shed more light on the subject, let's have a look at the basic functions of a solar charge controller:
Do you need a Solar Charge Controller?
Shunt Charge Controllers (Simple On/Off Controls)
As their name suggest, these are easy to work with. They are designed to allow a maximum amount of current to flow in through a blocking diode and automatically switch on once an upper threshold voltage is reached, thus preventing the battery from getting further charged. If the battery's charge falls below a lower threshold voltage they automatically switch off to allow current in. Until full charge, the controller will regulate the array of current flowing in.
Simple controls are the predecessors of modern day charge controllers which explains their fewer components. Now, they are not so commonly used due to their limited functions. Nevertheless, the reason they are still around can be attributed to their reliability and affordability. Additionally, they are suitable for wireless applications where electrical noise should be minimal.
Pulse Width Modulated Charge Controllers (PWM)
These are standard type of controllers designed to minimize the amount of current flowing into the battery, as it nears its set maximum charge point. When the battery is full, the controller utilizes the ' trickle effect' by only allowing small amounts of current in so as to keep the battery topped up. If solar energy supply is constant, PWM charge controllers can indefinitely maintain the battery's charge full.
To use this type of controller your battery(s) and solar panel(s) must have the same voltage. For instance, a 12V battery is required to hook up to a 12V PWM charge controller. Usually most homes which depend on solar energy to power the whole structure may not benefit from this type of controller as the battery and panel voltage are not typically the same. Hence the controller is considered most suitable for smaller solar systems using low voltages.
Maximum PowerPoint Tracking Charge Controllers (MPPT)
PWM vs MPPT - Which Charge Controller is Better?
Things to Consider when Choosing Charge Controller
There are a few things you need to factor in when selecting a suitable charge controller. Let's look at each one right now:
If for example, you need a solar energy system to power up your whole home, i.e. for lighting, cooking and heating purposes then an MPPT charge controller would be more ideal. Same case would apply if you want to power up an office structure. MPPT charge controllers can comfortably handle higher current and utilize it effectively. They also come in handy when future plans involve acquiring more solar panels.
However, if you only need solar power for a smaller PV system such as charging handheld devices, and lighting a single or few rooms, then a PWM charge controller is recommended.
Are you budget conscious and your energy needs are not really high? Then going for a PWM would be more sensible since MPPT charge controllers tend to be costly. Usually, different manufacturers offer different prices and the more features a charge controller has, the more you are likely to spend on it.
Temperature does influence the efficiency of charge controllers. PWM performs best in warm environments since they are designed to operate at battery voltage. Whereas, MPPT work best in cold environments and when the battery is low, since they can operate above battery voltage.
It all depends on the size and sophistication of a charge controller. If you are not able to install it by yourself then you will have to hire an expert which means extra costs. Due to their complex nature, MPPT controllers may give you a hard time during installation compared to PWM.
With the sophisticated features of modern MPPT, you may need to set aside funds to hire an expert during installation and maintenance procedures. You get what you pay for 🙂
Ensure to check a charge controllers warranty before obtaining it so as to ensure if anything goes wrong, you have the option to take it back or have it freely repaired. 1 year or more is considered ideal. During purchase, find out the terms and conditions governing your warranty to avoid violating them.
Remember your safety should always go first. Some people consider solar energy lesser compared to mains electricity power supply, hence do consider it as life threatening - it actually is! Reportedly there have been several accidents in the past resulting from solar power. To avoid this, if you are not sure about how to handle the technical details involving a charge controller, seek professional services.
Indeed, it is an overwhelming task to choose technology with which you are not familiar, especially when there are a wide range of brands available on the market. Lucky for you, you are now equipped with the information that you need to choose the best solar charge controller for your solar power system. If you are in a hurry, you can find some of the best charge controllers we recommended from here.
Remember, your solar panel, battery, and energy needs play a big role in determining which type of charge controller will work best for you. Check the manufacturer’s manual to get the technical details of your solar power system and use the above information to match it to the most ideal charge controller. The right model for you is the one that meets your budget and energy needs.
If you’ve found this guide useful, please share this article with your friends and let us know in the comments below or leave a comment on our social pages.
ABOUT THE AUTHOR
John is a digital marketer and grant writer. He is passionate advocates of telecommuting and the RV lifestyle. With 10+ years of living and traveling full-time in an RV with no end in sight, John is truly an RV Lifestyle Expert. His goal is to help others become more powerful by providing basic information on enhancing your RV lifestyle with Solar Power.