2016年11月2日星期三

Prospect of new Led auto market

According the report of D-Daily which is news agency of Korea. Estimating Led market scale will be 249 hundred million USD, And proportion of Led market will reach 57%,Especially residence and auto light which is the market has great potential, Can be create more growing rate.

According auto research agency report,High bright LED auto light appear strong growing, For long term use is safe energy,environment friendly,In auto market’s application will be great improvement.

Red LED tail light already be used in auto market more than a decade ago,But inter auto light and Led headlight is not popular until this years. For now proportion of LED application in auto inter indicator light part has 70%,background light of instrument display board has 45%,daytime light has 55%, And proportion of LED headlight is 20%. And the data of LED headlight is growing more and more fast lately.

Why the LED headlight growing so fast? Because LED has lots of advantage. Normally the bright of LED headlight is between Halogen and HID headlight,but the beam will be more spot,and also can be produced more shape of light. Moreover, LED’s size is more small, operation freeness will more high, thus customer has more optional to choice.

Why the Led headlight not popular in couple years ago?All because of the price. Except the LED headlight, and we also have incandescent light,Halogen,HID option. But the price of LED is higher than others before. The price is not really nice. But now DDL is develop a competitive price LED headlight with good quality to help our customer to occupied with their Auto LED market. And we persist in good quality and professional service to our customer.


2016年9月21日星期三

Why DDL be the best led car headlight factory?




DDL factory have been specialized in auto lighting for 7 years. For each model, we spend many times to research and development. So we are the best and professional led car headlight factory.




1)Traditional Halogen headlamp color temperature close to Yellow. Call “Dark Yellow”. Long time driving will cause vision tired.



2)DDL LED Light not afraid any strict weather - Safe driving.
 Normal car light will be effect by serious weather,Beam will be more difficult to go through the fog. At the same time,will produce more glaring and reflect,influence driving sight.So choose headlight which has strong penetration is the key of your driving.

Raining day,Haze day, Snow day, Strong foggy day. No matter what weather we are, DDL best led car headlight will be stand by your safe road.
  




3) 2th to 6th generation,DDL Keep upgrade to be a best led car headlight factory.
DDL factory is insist on professional technical upgrade. Extending life time,Improving the bright,Accelerating the heat dissipation.







4)Less defective rate.Driving power using wide voltage and constant current mode. Solving any non-stability car voltage situation,More effective protect Led running safety. Easy install,less defective rate, less 80% defective rate than HID ballast.

If you like the share,please kindly share to your post.


Mandy Yang
Tel/Whats:+86 13229971542
Email:xr005@xurihid.com
Skype:xr005

2016年8月10日星期三

What is COB?

COB 
COB (Chips on Board) , is a new technology of LED packaging for LED light engine. Multi LED chips are packaged together as one lighting module. When it light up, it looks like a lighting panel..                                       

Why COB? --Background
LED(light emitting diode) is new technology with advantage of saving energy and very long lifespan. But all LED lightsource can not be faultless especially SMD, HP, flux LED etc. Compare to traditional lighting such as fluorescent lamp, as it is super bright in a small size, it cause uncomfortable glare. In case of no diffused optical lens used, such LEDs usually cause glare and zebra strips . But when optical lens or cover used, it will cause light loss when LED beam pass through this lens or cover.


How COB LED Light source works 
COB LED is multi chips packaged, it can 10 times more increase lighting area, so it avoid uncomfortable glare by the maximum extent. 
Lightspot use small size of chips to make COB LED package.
By now, for small size chip, ?some famous LED chip manufacturer can reach 249lm/watt @ 20mA. But big size LED chip can only reach 161lm/watt @350mA. The light efficacy decrease when chip size is bigger. Also when LED driver increase current to LED, the light efficacy per watt is even low.

The COB with small size chips will be a trend of LED light source package.
Lightspot holds the patent for invention for COB LED and lamp.
Advantage of COB 
COB LED has a lot of advantges. For details of advantage of COB, click http://www.cob-led.com/http://www.cob-led.com/COB-LED-Advantage-Chip-on-board.html
Application of COB Technology 
1, COB LED light sources

2, LED lighting fixture which use COB LED light source

Whats COB LED?
COB LED means chip on board LED, its one of bare chip technologies, which interconnect bare chip to substrate by conductive or non-conductive adhesive, and then wire bonding to achieve its electrical connection. COB package is attach number of chips directly to the substrate, then packaged together by silica gel, epoxy resin or other materials, the yellow part is phosphor.
Produce process:
The first step of COB package is to cover wafer placement point on the substrate surface by thermal conductive epoxy (usually is epoxy resin mixed with silver particles). Second is put the wafer on the substrate surface directly, then fix wafer to the substrate firmly by heat treatment. Third is to establish electrical connection between wafer and the substrate by wire bonding method.

COB LED advantages:
COB light source can save about 30% cost in the application, mainly lie in LED package cost, light engine production costs and the secondary light distribution costs, which is great significance for applications and promotion of semiconductor lighting.
In performance, through the rational design and micro-lens molding, COB light module can avoid the defects of point and glare light also other flaws existed in discrete light source device. It also can add some red chips appropriately, so that to improve the CRI effectively under the condition of without reduce light efficiency and lifetime significantly.
In application, COB module makes production of lighting manufacturer more simple and convenient, and reduces cost effectively. In production, the existing technology and equipment can support high yield and large-scale COB module manufacturing.
With the development of LED lighting market, lighting demand is growing rapidly, according to different inquires of lighting applications, we can produce a series COB light source module for mass production.
COB LED disadvantages:
COB packaging technology bottleneck is how to improve the reliability of the light source, and its operating temperature. However, most of the current market COB packaging companies are small and they mostly use aluminum substrate as the material. Aluminum COB reliability is low because of its greater thermal resistance, easy to cause death LED or high light attenuation. The ceramic substrate is an ideal COB material, but its cost is relatively high, especially for the power less than 2W, difficult to be accepted by customer.
Also, the demand of COB light source on the market is still low by now. In addition, COB LED exist standardization issues, the standards of package manufacturers and lighting factories are not the same, so the two parties have difficult in integration.
Application:
Currently, the main applications for COB LED are and mining lamps, spot lights, street lights and so on. 

2.Five Popular Single row led light bar in the market

While you are behind the steering of your vehicle, you shall always want to have the best feel and experience whilst driving and that will only happen if you have the best and clear visibility on the road
A high quality light bar can make a significant difference in your ability to see clearly and drive safely on the darkest roads.
If you are looking for the best light bar to improve visibility on your daily drive, it is wise to research the best products and developing technology.
In this guide we feature comparisons of LED technology, explain why certain products are superior, provide tips on how to choose the best unit and much more. You will learn the characteristics of a quality light bar in order to distinguish it from a cheap model. 
Before making a final decision on the type of LED light bar you want to buy carry out a background research and do comparison between the various brands of LED light bars in the market to determine their quality and prices.
Learn to differentiate between high quality LED bars, though those may be a little bit expensive and the low quality cheaply made ones. This knowledge will ensure that you always get the best product for your bucks.





2016年8月2日星期二

Single row led light bar vs double row led light bar?

Light Bars have been widely used for offroad ,truck ,tractor, utv ,suv ,atv ,4x4 ,while the vehicle owners are still confused how to distinguish them

Almost every vehicle owner knows that having extra illumination at night can be a huge advantage. You can easily see what's in front of your car. What's more, having extra illumination can also come in handy in emergency situations. These are some of the reasons why people purchase light bars for their vehicles. With the extra illumination provided by the lighting devices, they can avoid accidents and ensure their safety at night.

If you're planning to purchase such lighting devices, keep in mind that there are two major types of LED light bars: single row and double row led light bars. While they basically offer the same functionality, there are certain differences between the two of them when it comes to features and structural design among other things.

So what are the difference between a single row LED light bar and a double row LED lightbar? As the name implies, a single row LED light bar is basically composed of a single, horizontal row of LED light bulbs. And when it comes to style of illumination, it has a little less flood beam but it produces better spot beam. This makes a single row LED an ideal choice if you want your lights to reach farther distances.

A double row LED light bar, on the other hand, has two horizontal rows of LED light bulbs that sit on top of each other. If you need wider coverage of illumination, purchasing a double row LED is your best bet. Double rows produce better flood style of illumination as compared to single row LEDs.

Although single row light bars have a single row of LED light bulbs in them, it doesn't necessarily mean that they are less powerful than double row light bars. A 120-watt single row LED and 120-watt double row LED are both capable of producing lights with the same brightness.

Sure, a single row may have fewer light bulbs as compared to a double row. However, each light bulb has higher wattage than those found in a double row light bar. For instance, if the single row light bar has 12 LED light bulbs, each bulb will have a power of 10W. Whereas if the double row light bar has 40 LED light bulbs, each bulb will have a power of just 3W.

Meanwhile, you're probably wondering what's this flood or spot style of illumination is all about. Well, these two lighting types produce significantly different beams intended for very different purposes. Basically, the width of the beam distinguishes floodlights from spotlights.

People choose and buy light bars with more flood beam if they want to illuminate a wider area. In contrast, light bars that have more spot beam on them are used to illuminate specific points because they can cover farther distances. In addition, lights that product spot style of illumination appear brighter than floodlights, even if they have the same wattage. It is because they produce highly concentrated beams of light as compared to those with flood style of illumination.

Not only care about the power or lumen anymore ,know your purpose of the light bars and then it is clear for you how to choose suitable light bars for your vehicle

2.Technical Specification should pay attention when choosing the Single row led light bar?

No matter you are the first time to buy led light bars or you have bought for several times ,do you feel confused and hard to choose it ? Cause you dont know which parts should pay attention to ,maybe something is similar to you

Size
The first most important factor you will want to consider is what size light bar you want. The larger a light bar is, the more bulbs it will have, meaning that the bigger you go the brighter your light will be. In spite of this, there are plenty of smaller LED light bars that still produce tons of light. LED light bars range in size from 4 inches all the way up to 52 inches, and which one is best for you really depends on your vehicle,your budget and the position you want to install

Shape
Deciding whether to purchase a curved LED light bar or a straight LED light bar is really a matter of personal preference. With neither shape having a clear advantage over the other, the choice is a matter of aesthetics. Pick which shape appeals to you most and go from here.


Number of Rows: Single or Double Row LED Light Bar

LED light bars either come equipped with a single row of LED bulbs or two rows of LED bulbs. Double row light bars are obviously going to produce more light, and though they are a little pricier, are usually the preferred choice of the two. If you are looking for a low-profile LED light bar, however, you will probably be limited to a single row of LEDs. Though the double row lights are brighter, which type looks best really depends on your vehicle and your personal tastes.

Beam Pattern: Spot, Flood or Combination

The beam pattern of an LED light bar refers to how wide of a beam the light produces. Spot beams are much narrower and reach a longer distance, making them preferred for on-road driving. Inversely, flood beams are much wider, and since obstacles at the side of the road are more of a concern on a backroad trail, the best off road led light bar is one that is equipped with flood beam bulbs. To be covered no matter the situation, consider purchasing an LED light bar with a combination beam pattern that is equipped with both flood and spot LEDs. This is a highly popular choice, and most of the best LED light bars available today come with both spot and flood LED bulbs.

LED Color
Certain colors are advantageous for certain situations. White light, for example, is the brightest color and is the best for most driving situations. Amber light, however, is better for fog and low visibility conditions since it does not reflect back into your eyes. Colors such as blue and red are good attention-getters and are preferred for emergency vehicles. Besides these, there are a also a variety of colors such as green that are made purely for aesthetic value. Like beam patterns, some light bars come equipped with bulbs of multiple colors. Choosing which color works best for you is a matter of intended purpose as well as personal tastes.

Water Resistance
Between rain showers and mud puddles, your LED light bar is certain to get soaked. If you are searching for the best LED light bar for marine uses, this is even truer. In order to make sure that water doesn’t corrupt the electronics inside your light bar, you will want to purchase a light that is completely water resistant. In order to see how much protection a light offers against water, check its IP rating. An IP rating of IP68 or IP69 are both excellent ratings, with IP69 being the highest possible. These ratings ensure that your light is able to survive complete submersion without allowing water to penetrate through to the electronics inside.

Connector Type
Wiring up an LED light bar doesn’t have to be a complicated task, but to make the process go smoothly, you will want to make sure you have the right connectors. All LED light bars either come with ATP or DT connectors. Match this connector type with your wires and you will be all set to mount your light.

Voltage
While every light bar is made to run off of a standard 12V battery, there are still three different voltage levels that they come in—12V, 24V, and 48V. Generally, the more voltage a light bar is rated for, the brighter it will be and the more power it will consume.

LED Chip
Usually there are CREE ,Epistar ,Philips ,OSRAM led chip for light bars ,CREE and Epistar is the most widely used. CREE is with higher luminous attenuation and high quality ,Epistar is with good price relatively.

Any more questions ,welcome to contact the led light bar factory


2016年7月27日星期三

What is the brightest h4 headlight bulb?



Now everything wants the brightest h4 headlight bulb for their own car or vehicles ,while what is the brightest one and how to choose the bulbs ?

Most of people know that the power and lumen stand for the brightness for headlight bulbs and most of them only check the power and lumen when they buy it ,while cause of that many sellers know this and then some of them write the power and lumen much higher to attract the customers to buy it .  So even they do not write high ,it has some loss and it has a raw lumen and effective lumen. So when you are buying it ,you can ask the seller the effective power and lumen and also the test report

After checking it and you need to test it by yourself ,of course it is check the lighting performance when you install.  

This is still not enough ,cause some lights are very bright at the beginning ,but after you use for some days ,it is not bright any more.This is the problem of luminous attenuation and heat dissipation ,while how to check the luminous attenuation ? Usually you can check it by the led chip ,try your best to buy the genuine brand led ,such as CREE,Philips which is higher luminous attenuation. The best heat dissipation is still the fan up to now

So the best brightest h4 headlight bulb is CREE or Philips led headlight with fan



1.Jeep Headlight Wiring Harness

Most stock components on a vehicle are designed to a specific level of performance and nothing more. The factory headlights on a Jeep TJ are no exception. They do exactly what they were intended to do: They light up and allow you to see a little way down the road.
We realized pretty quickly that the stock, yellowish, headlights simply were not going to cut it. But, we also wanted more with this Jeep than the usual Sylvania Silverstars upgrade could give us. Once we started shopping for aftermarket headlights, it readily became apparent that any quality aftermarket light would be a substantial improvement, but to fully realize their potential the worn out stock wiring would need to be addressed.
Taking a voltmeter to our project vehicle, and a couple others, we found the power actually making it to the headlights (measured with the engine running and the headlights on) was about 12 volts on our TJ and as low as 9 volts on an older XJ. None of them actually showed us the full 14 volts we measured at the battery. So before we get into swapping in new bulbs, lets go through building the foundation for some really kick-butt headlights.



2016年7月14日星期四

Should We Change our lights into LED?


Drivers may soon notice brighter and whiter headlights on the road as the popularity of traditional halogen headlights continues to dim.Halogen still ranks highest as the most common headlight on the market, but several alternatives, including xenon-based and light-emitting diode (LED) headlights, are growing in popularity. Here's how the options compare in terms of performance, safety and price.
  According to Motor Trend, you'll notice several important differences in light produced by LEDs, xenon and halogen headlights. LEDs have the coolest color temperature at around 6,000 Kelvin, which makes them appear whiter than daylight. Xenon headlights come in at around 4,500 K, while halogens round out the list at a yellowish 3,200 K.When it comes to reflection, LEDs offer better light return from road signs, while xenon lamps better illuminate the sides of the road. In part, this is because xenon lamps typically produce more light, measured in lumens, than LEDs.Both LEDs and xenon provide a large pattern of light on the road, whereas halogens offer a small pool of yellow light directly in front of the vehicle. If you're buying a new car, expect LED headlights to be the premium option, and make sure your auto repair shop is equipped to handle LED headlight replacements and repairs.If you're looking for intense light and don't mind the glare, xenon may be the best choice. LEDs, meanwhile, offer great light, low power and long life, but often come with a bigger price tag.
  LEDs are the most recent innovation in headlight technology. Instead of gas and filaments, LEDs rely on small diodes that produce light when electric current excites their electrons. They need an low amount of power to work but do produce a significant amount of heat on the diode. This requires heat control systems at the bottom of the headlight and near other car components. If this system fails, not just the light, but other electronics could be affected.The small size of LEDs means they can be formed into almost any shape, and their light is naturally directional rather than diffuse, making them an excellent choice for headlights.

2016年7月4日星期一

What are the differences of the beam pattern?



There are many types beam pattern for led work driving light and led light bar,while the most popular and widely used is these 4 types: Spot (Long Range), Driving and Spread, Fog, and Flood.

Spot Beam (Long Range): Spot or Long Range lights are able to penetrate deep into the night. KC Long Range Lights produce a tighter, more focused circular beam of light (pencil beam) to see way out ahead toward the horizon even at higher speeds. These lights create an extremely bright, hot center beam pattern. Spot beam lights are typically used for Off Highway, Commercial, Agricultural and Racing applications.

Driving and Spread Beam: Driving lights are designed to supplement your high beam headlights.  KC's Driving lights all comply to both SAE and ECE regulations and requirements and are street legal. KC Driving Lights produce a rectangular shaped beam pattern that can reach further and wider than your headlights.  Driving lights are very useful to create visibilty near the sides of roadways and out in front of the vehicle. They are great for all around trail riding as well.

Spread beam lights are similar to Driving but tend to be brighter, wider and possibly taller as they are not required to follow specific SAE or ECE safety standards.  Spread beam lights are great lights for multi-purpose off-road use.


Fog Beam: Fog lights are intended to be mounted below the headlights and project a beam pattern which is very wide horizontally and narrow vertically usually called a cut-off. This pattern lights up a pathway close to the ground but does not light the airborne particles in the line of sight while driving - this increases the visibility in harder to see conditions. KC Fog beams are very useful in Dust, Fog, Rain and Snow. They also work well as Cornering lights in clear conditions and are optically designed to increase visibility in tandem with your primary headlights.

Flood Beam: Flood beams create a large wide pattern of light that floods an area with an extremely tall vertical and wide horizontal light pattern. These lights are typically used as work lights and back-up lights to see a broader area at shorter distances.




Pls choose the right beam pattern for your application

Trapezoidal Beam:The trapezoidal beam (shown in dotted lines) is an ideal, general-purpose work light designed with a narrower pattern for longer visibility


2. Five things to consider before buying car led lighting
When your halogen car lighting is not enough bright as you want, it's a good time to consider switching to LED.
LEDs have an impressive lifespan (50000hours!) and are very cost-effective.
Now's the right time to switch to LEDs. These bulbs have made significant advances over the last few years, Because there are so many LED varieties, choosing an LED is entirely different from many types. Before you head to the store, find out what you need to know about choosing the right LED bulbs.

Lumens, not watts

Forget what you know about halogen -- your watts are no good here.
When shopping for bulbs, you're probably accustomed to looking for watts, an indication of how bright the bulb will be. The brightness of LEDs, however, is determined a little differently.
Contrary to common belief, wattage isn't an indication of brightness, but a measurement of how much energy the bulb draws. For incandescents, there is an accepted correlation between the watts drawn and the brightness, but for LEDs, watts aren't a great predictor of how bright the bulb will be. (The point, after all, is that they draw less energy.)
For example, an LED bulb with comparable brightness to a 60W incandescent is only 8 to 12 watts.
But don't bother doing the math -- there isn't a uniform way to covert incandescent watts to LED watts. Instead, a different form of measurement should be used: lumens.
The lumen (lm) is the real measurement of brightness provided by a light bulb, and is the number you should look for when shopping for LEDs.

Choosing the right color LED

You can always count on halogen providing a warm, yellowish hue. But LEDs come in a wide range of colors
.

Candace Lombardi/CNET
As shown off by the Philips Hue, LED bulbs are capable of displaying an impressive color range, from purple to red, to a spectrum of whites and yellows. For the home, however, you're likely looking for something similar to the light that incandescents produce.
The popular colors available for LEDs are "warm white" or "soft white," and "bright white."
Warm white and soft white will produce a yellow hue, close to incandescents, while bulbs labeled as bright white will produce a whiter light, closer to daylight and similar to what you see in retail stores.
If you want to get technical, light color (color temperature) is measured in kelvins. The lower the number, the warmer (yellower) the light. So, your typical incandescent is somewhere between 2,700 and 3,500K. If that's the color you're going for, look for this range while shopping for LED bulbs.

You'll pay more for an LED bulb

LED bulbs are like hybrid cars: cheaper to operate but pricey upfront.
When switching to LED bulbs, don't expect to save buckets of cash. Instead, think of it as an investment. Luckily, competition has increased and LED bulbs have come down in price (like this $5 LED from Philips), but you should still expect to pay much more than an incandescent.
Eventually, the LED bulbs will pay off, and in the meantime, you'll enjoy less heat production, longer bulb life, and even the option of controlling them with your smartphone.
Bottom line: unless you're replacing many incandescent bulbs in a large house, you won't see significant savings in your electricity bill.
For a detailed breakdown of the cost-effectiveness of LED bulbs, check out this useful post.

Watch out for non-dimmable LEDs

Because of their circuitry, LEDs are not always compatible with traditional dimming switches. In some cases, the switch must be replaced. Other times, you'll pay a little more for a compatible LED.
Most dimmers, which were likely designed to work with incandescents, work by cutting off the amount of electricity sent to the bulb. The less electricity drawn, the dimmer the light. But with your newly acquired knowledge of LED lingo, you know that there is no direct correlation between LED brightness and energy drawn.
This guide explains why some LEDs will hum, flickr, or buzz when tied to a dimmer.
If you'd like your LED to be dimmable, you need to do one of two things: find LED bulbs compatible with traditional dimmers, or replace your current dimming switch with a leading-edge (LED-compatible) dimmer.
When shopping for LEDs, it helps to know what kind of dimming switch you have, but if you don't know (or would rather not go through the trouble), simply search for LED bulbs compatible with standard incandescent dimmers. To make things easier for you, we tested a slew of them to find out which LED bulbs work best with dimmers.

Not all light fixtures should use LEDs

Knowing where it's OK to place an LED will ensure that the bulb won't fizzle ahead of its time.
You probably know that LED bulbs run dramatically cooler than their incandescent cousins, but that doesn't mean they don't produce heat. LED bulbs do get hot, but the heat is pulled away by a heat sink in the base of the bulb. From there, the heat dissipates into the air and the LED bulb stays cool, helping to keep its promise of a very long life.
And therein lies the problem: the bulb needs a way to dissipate the heat. If an LED bulb is placed in an enclosed housing, the heat won't have anywhere to go, sending it right back to the bulb, and sentencing it to a slow and painful death.
Consider where you'd like to place your LED bulbs. If you have fully or semi-enclosed fixtures you need to light up, look for LEDs that are approved for recessed or enclosed spaces.
3.5 steps you should know before buying led work light
A work light is used in a particular job-related situation, such as for automobile mechanics repair, theater technical setup, mining and marine applications. It can also be used for automotive lighting, patrolling, hunting and other moving environments. When you choose a work light, youd better consider the specifications in terms of your working environment.
To judge if the LED work light you are considering is the best choice for you, there are some features that you can compare.
1) Type (Beam pattern)
The first thing you should notice is the type of light. Consider what type you want, floodlight, flashlight or off-road light. Floodlight is widely used to provide wide-angle lighting for outdoor work in construction sites and other facilities. Flashlight is widely used for emergency lighting and is usually rechargeable. Off-road light is applied to automotive lighting. So choose the type of work lamp according to the purpose of your project. Then you should narrow your choice according to the following features.

2) Size
The size of the device is critical. In certain work situations, the space is limited, so you cannot choose a bulky work light, otherwise you will not have enough space to operate. Of course, when space is sufficient, the lamp size will not be an issue.
The size is from 2inch to 9inch,pls choose the one suitable for your device
3) Power & heat output
If your work needs intense bright light especially in industrial and mining areas, construction sites and so on, you should choose a high-power work lamp. The higher the power is, the higher the intensity is. However, a higher power usually transforms to higher heat generation. If a light emits a lot of heat, the space will be too hot for the device to function properly and people will feel uncomfortable, especially in a narrow room. So you should balance the power and heat output to reach a best combination for your work conditions.
4) Power supply
Most flashlights use dry batteries as power supply. Then you will need to replace the batteries from time to time when they run out of power. Some work lights work on built-in rechargeable batteries. For this type of light, it is be important to know the operating time and the recharging time. In addition, the available chargers might influence your decision, too. A rechargeable work light is often sold with an AC charger or car charger or both.
5) Fixation. 
Another vital factor is how the LED work light is kept in position. Work lights come in varieties of designs, including bar light with a hook on one end, hand-held flashlight, floodlight with a handle, lamp on a tripod and a lot more. So find the most convenient method for you to place the work lamp and choose the best fit design and feature accordingly.
There may be other features that you need to consider, such as waterproof grade, slip-resistance, shock-proof, overcharge protection, rotation and so on.