It takes a lot of money to install a home solar power system. Of course, the part that people care most about is the amount of electricity generated. as the general of an off-grid power system, the solar battery charge controller plays an even vital role than ever before.
As the core component of the solar power generation system, solar controller often costs less than 10% of the total system cost, but its role is far more than this. The performance of the solar controller largely affects the whole The amount of electricity generated by the system.
Therefore, when choosing a solar controller, you can’t just focus on the price of the solar controller. The key is to see if it can bring high power generation.
The roller with the highest power generation from the key parameters are many parameters listed on the parameter list of the solar controller manufacturers, but only a few can really affect the power generation.
The next thing to tell everyone is tips from zhcsolar experts
10 Tips for choosing a Solar battery charge controller
1. Know Your System Requirements
the right solar battery controller rating influences the ability and performance of the solar power system.
be remember to Choose the right controller that fits your system most, the solar battery charger is rated by amp normally, the most welcome rate in the market is 30 Amp, 40 amp and 60 amp for a common home solar system.
sizing the solar battery charge controller is simply calculated the value of solar panels watts divided by the battery voltage, for example, when we use 250 Watts Panels, and connect it to a 24V battery, then the formula is 250/24=10.4 and usually we give 25% safe margin there, so the 15A Solar battery charge controller is good to go.
2. Solar Panel Charge Controller Quality
A Good Solar Battery Charge Controller is related to 3 aspects: It is easy to install, clearly marked and easy to set up.
When Choosing the solar controller, first check the appearances as follow steps.
1. Look at the controller appearance. The smoother and more beautiful the product, the higher the precision of the mold used.
2. Look at Product Processing. In the purchase of products, you can see whether the joint is tight, the use of screws, buttons and other small parts whether delicate production, installation is tight, contact is good and so on.
3. Look at the Parts and components: checking the internal structure diagram of the controller, check whether the layout is reasonable and material used is sufficient, which direly related to the service life of the solar panel charge controller.
3. Low Power Consumption
You should choose a controller with low power consumption. The controller works 24 hours a Day. If its own power consumption is large, it will consume part of the electric energy generated, is best to choose a solar battery charge controller that consumes less than 3 ma.
4. High Conversion Efficiency
High conversion efficiency means that you can get higher power generation from the solar array. normally, A PWM Solar Controller Charging conversion efficiency is about 75 to 80 percent, but solar panels are still not fully utilized.
MPPT is a better choice because the charge conversion efficiency can reach to 95% to 98%, a good MPPT charge controller converts even as high as 99%.
5. Good Heat Dissipation
As the key Part of energy conversion, solar energy will generate a lot of heat during the operation of the controller. At this time, good fan heat design is very important.
In order to reduce costs, many controllers do not consider heat dissipation. In this way, when the load current is large or the charging current is large, the heat will increase, and the internal resistance of the field pipe in the controller will be increased, leading to a sharp decline in charging efficiency.
after overheating, the service life of the field pipe is greatly reduced or even burned down. Especially in summer, the outdoor environment temperature is very high, so a good heat dissipation design should be essential for the controller.
Almost all solar controllers nowadays have fins on the back for a cooling, and many MPPT controllers even have built-in fans, longer and a thicker heat sink is a plus for choice.
6. Line Loss Compensation
The function of line loss compensation is difficult to be achieved by conventional controllers at present because it requires a software setting to give automatic compensation according to different line diameter and line length. In fact, line loss compensation is very important in the low-voltage system.
Because the voltage is low, the line loss is relatively large, if there is no line loss voltage compensation, the output end voltage may be lower than the input end, which will cause the battery tuning into Undervoltage protection, the actual using rate of the battery capacity is discounted.
Note that when using low voltage systems, in order to reduce the loss pressure drop. try not to use too thin or too long cables.
7. Ground Design
There 2 Ground design Modes for a solar battery charge controller, positive ground and negative ground design.
In simple words, all vehicles have a NEGATIVE ground system, so when choosing MPPT Solar Charge Controller for RV, Autos and Boat, remember to choose the Negative Grounding Charge Controller.
8. Good Customer Service & Warranty
When customers buy solar controllers, they want to be reassured that they’re making the best decision possible. good customer service includes fast responses on real-time chat, calling answers and emails. Well, some biggest platform such as Amazon, eBay does not have a good response rate due to the bad communication channel, ZHCSolar Provides the best customer service as 24-hour online chatting service.
9. Product Protection
a good solar panel charge controller usually has Good circuit protection functions, including PV reverse connection protection, PV over-current protection, battery reverse connection protection, battery over-voltage protection, battery over-discharge protection, load over-current protection, load short-circuit protection, etc.
1. Overcharge Protection: when the charging voltage is higher than the protection voltage, it will automatically turn off the battery to charge. After that, when the voltage drops to the maintenance voltage, the battery will enter the floating charge state.
2. Over-discharge Protection: when the battery voltage is lower than the protection voltage, the controller automatically turns off the output to protect the battery from damage. When the battery is recharged, it will automatically restore power.
3. Load current and short circuit protection: after the load current exceeds 10A or the load short circuit, the fuse wire will blowout, and cannot working before replacement.
4. Overvoltage protection: when the voltage is too high, the system automatically shut down the output, protect the electrical appliances from damage.
5. Anti-reverse charging function: Schottky diode is adapted to prevent the battery from charging to the solar cell.
6. Anti-lightning function: when lightning strikes, varistors can prevent lightning strikes and protect the controller from damage.
7. Solar cell reverses connection protection: solar cell “+” “-” polarity is reversed, correct it before using the system.
8. Battery reverse connection protection: when battery “+” “-” reverse polarity connection, the fuse blowout, replace it then continue to use
Good protection ensures maximum service life and safety both to user and systems.
The price of the MPPT solar charge controller is usually 3-5 times then the PWM controller which in the same size (amp). Generally, the price difference of the small amp is not as much as the big amps.
In the long run, the MPPT charge controller has a higher return on investment, not matter for the home off-grid system or for commercial purposes. We strongly recommend taking an MPPT controller for your power system.
As you explore solar battery charge controllers, you’ll discover that some factors are not as important to you as others. In fact, the whole point of going through the process outlined in this guide is to discover what aspects of the solar controller will determine your focus as you research. Ultimately, you want to pick a solar charger controller that meet your needs. we recommend taking the famous brand products like EPever, ZHCSolar to try first.