How to get a qualified all in one solar street lights?
needless to say, the quality of products is very important to businesses, sometimes, is crucial for winning tenders.
But can you always get a qualified all in one solar street light? I doubt it.
You might encounter problems:
- even if you have been in this business for years, but you still have no idea about what exactly standards for an eligible product?
- you might have learned the standards, but how to achieve? What factors affect the quality?
Let’s dive in the content with these questions you may have.
For almost all kinds of integrated solar street lights, QC mainly focuses on the following items:
- CCT & CRI
- LM80 standard
- Battery cycle times
- 3 transportation testing for lithium batteries
- Ingress Protection standard
- Working temperature
Let’s review each one in detail.
CCT & CRI
CCT & CRI are important optical factors for illuminating
CCT stands for correlated color temperature. lower value tends to yellow, while larger value tends to white and even with a little blueish color, refer to 8000K in the picture.
3000K looks like the sunlight at dusk or daybreak, the sunlight at noon is around 5000K, 6500K is called natural white, compact fluorescent lamp commonly has 6000-7000K.
Nowadays, nature white(6000-7000K) is always using in solar street lights.
Color rendering index (CRI) indicates how well a light source allows the substance to reflect its real color, the higher the CRI, the more an object can reflect its real color under this light source. Refer to the CRI 80 VS CRI 90
However, larger CRI also means more brightness loss as compensation. Namely, when we use the same chips to produce LED, if we make it with higher CRI, its brightness will be relatively dimmer than the one with lower CRI, so we commonly apply CRI 70 to the solar street light industry to get somewhat equilibrium.
With the help of the integrating sphere, we can easily get the two optical parameters when inspecting the incoming raw materials. In fact, integrating sphere can also help to get even more electrical parameters, such as illuminance(brightness), lighting efficacy and so on.
LM80 is related to the lumen maintenance of LED, this standard requires the LED to meet the following table
|Working time(hours)||brightness depreciation(%)|
Since human eyes will not perceive the depreciation until it drops to 30%, an LM80 certified LED can definitely walk you through 50, 000 hours without becoming dim sensorily
Some types of equipment are specially designed to do this test accordingly, although it is very expensive.
If you do not want to invest such huge and expensive facilities, our advice is to complete the job in a third party laboratory with little payment.
Battery cycle time
Battery seems to be the most vulnerable part, they have the higher failure rates than the others, its lifespan depends on not only the materials and workmanship but also how we use it, for examples, how many proportions of power is discharged before next charging, specifically, the depth of discharge (DoD)
In solar street lights systems, the larger proportion the batteries are discharged every day, the shorter its cycle times will be.
Batteries manufacturers declare the cycle times of their lithium battery to be 1000 – 1500 times, which is based on the scenario that the battery is almost fully discharged each time.
However, we need to verify this data by ourselves so as to be responsible for the quality
Use an instrument like this one can help to record the testing data automatically, some of them have UPS(Uninterrupted Power Supply) function to guarantee a complete testing process and the data integrity.
UN38.3 transportation testing for lithium batteries
UN38.3 is for the safety of transportation of batteries or products with batteries, it includes 8 test items
- Altitude Simulation
- Thermal Test
- External Short Circuit
- Forced Discharge
Over those procedures, UN38.8 requires there is no leakage, no venting, no disassembly, no rupture, and no fire.
These are more extreme test conditions compared with normal working conditions, products which have passed UN38.3 are definitely able to perform better.
You can check the PDF file to see how we test our products according to UN38.3 directives
Ingress Protection standard
All in one integrated solar street lights are outdoor lighting, so they have to withstand a hostile environment where they may fail to work because of dust or rainfall.
Ingress Protection(IP) rating is used to define the grades of resistance against dust and water.
Outdoor lighting fixtures are usually with an IP65 rating, which is the highest protection level for outdoor luminaire except for underwater luminaire. The first digit 6 is for dust and the second digit 5 is for water.
Though there is waterproof seals set between the enclosure over the final assembly, those interior components themselves are watertight too. For instance, the wiring connectors are all waterproof, and the controller is IP67 rating.
Apparently, referring to the picture above, a mimic raining environment is necessary for final testing, and it is more useful during the stage of design or pilot production.
If you do not have a spacious site for this kind of voluminous facility, we also suggest seeking a third party laboratory to help you with this work.
Outdoor temperature varies with location or season, the working temperature will directly affect the performance of each component or even lifespan in some extreme situations.
So either respective modules or assembled products needs testing and monitoring.
Engineering and QC take in charge of these jobs in a factory, when:
- new product design,
- pilot production,
- raw material changes,
As with others, these processes also rely on special tools.
The equipment is used to imitate various working environments to test the tolerance of electronic products. The technician can also set worse working temperature than a real condition to check whether the electronic modules could survive from the testing.