What are the best batteries for solar? Batteries used in home energy storage typically are made with one of three chemical compositions: lead acid, lithium ion, and saltwater. In most cases, lithium ion batteries are the best option for a solar panel system, though other battery types can be more affordable.
If you install a solar battery today, you will likely need to replace it at least once to match the 25 to 30 year lifespan of your PV system. However, just as the lifespan of solar panels has increased significantly in the past decade, it is expected that solar batteries will follow suit as the market for energy storage solutions grows.
The most important ones to use during your evaluation are the battery`s capacity & power ratings, depth of discharge (DoD), round-trip efficiency, warranty, and manufacturer. Capacity is the total amount of electricity that a solar battery can store, measured in kilowatt-hours (kWh).
Batteries used in home energy storage typically are made with one of three chemical compositions: lead acid, lithium ion, and saltwater. In most cases, lithium ion batteries are the best option for a solar panel system, though other battery types can be more affordable. 12V Solar Battery,Solar Battery Storage,Solar Deep Cycle Battery,Lithium Batteries For Solar Systems 12V Shenzhen Glida Electronics Co., Ltd. , https://www.szglida.com
In the pyroelectric sensor, a one-way sensor has been used in the past, and the one-way sensor is relatively affected by factors such as stray light, and the application effect is relatively poor. Therefore, the dual-sensor unit is now commonly used, and this sensor has the following advantages: 
How infrared sensors work
Infrared intelligent power-saving switch is an automatic control product based on infrared technology. When someone enters the sensing range, the special sensor detects the change of the infrared spectrum of the human body, automatically turns on the load, and the person does not leave the sensing range, and will continue to be connected; after the person leaves The delay automatically turns off the load. When people turn on the lights, people turn off the lights, they are friendly and convenient, safe and energy-saving, and they show humanized care.
First, infrared spectroscopy
The light that people can see with the naked eye is called visible light, and the wavelength of visible light is 380-750 nm. The wavelength of visible light is from purple to blue, blue light, green light, yellow light, orange light, and red light. Light with a longer wavelength than red light is called infrared light, or infrared light (infrared). Infrared light is the light that people cannot see with the naked eye. The wavelength distribution of the light in the part of the population is as follows:
Violet (O.40～0.43μm); blue light (0.43～0.47μm); cyan (O.47～0.50μm); green light (0.50～0.56μm); yellow light (0.56～0.59μm); orange light 0.59～0.62μm); red light (0.62～0.76μm); infrared (0.76～1000μm); infrared light can be further divided into:
Near infrared (760 ~ 3000nm); mid-infrared (3000 ~ 6000rim); far infrared (6000 ~ 150,000nm).
Any object with temperature in nature will radiate infrared light, except that the infrared wavelength of the radiation is different. According to experiments, the infrared (energy) wavelength of human radiation is mainly concentrated at about 10000 nm. According to this characteristic of the infrared wavelength of the human body, if a detecting device is used, infrared rays radiated by the human body can be detected to remove unnecessary light waves.
The purpose of detecting human activity information can be achieved. Therefore, there has been a sensor product that detects infrared rays of the human body. The human body infrared sensor is made according to the pyroelectric principle.
Second, the principle of pyroelectric
The human body infrared sensor is a sensing product made by the principle of pyroelectric effect. What is the pyroelectric effect? It is a phenomenon in which electric charge is generated due to changes in temperature.
In order to clearly explain the pyroelectric effect is also seen. Schematically illustrated.
1 is a schematic diagram of a temperature change curve: FIG. 2 is a schematic diagram showing a state change state of a sensor surface charge caused by a temperature change; and FIG. 3 is a schematic diagram of a voltage change output curve caused by a change in surface charge of the sensor.
At the beginning of Figure 1, (T), the temperature of the pyroelectric infrared sensor does not change without infrared radiation, the charge on the surface of the sensor is in a neutral state, and the positive and negative electrons are equal (A). At this time, the sensor has no output ( 0). Figure 2 The second stage (T + △ T), when there is a temperature change. When the temperature of the pyroelectric infrared sensor rises by ΔT under the irradiation of human body infrared rays, the electric charge on the surface of the sensor changes correspondingly as shown in Fig. 2(B). If the temperature changes to ΔT, the corresponding change in charge produces a change in ΔV, so the sensor outputs ΔV. Over time, the sensor surface re-adsorbs ions in the air and cancels each other out to achieve a neutralized state as shown in Figure 2c. At this point, the sensor returns to no output (O). As shown in Figure 3.
When the temperature drops, the temperature returns to the original state (T), and its free polarization state is as shown in Fig. 2D. Since the temperature change component (relatively speaking) is opposite to the temperature rise change, the charge change of the sensor table is just the opposite of the change process when it rises, which is a reverse process.
Therefore, the output signal of the sensor is a ΔV, as shown in Figure 3. Similarly, as time passes, the surface of the sensor re-adsorbs ions in the air, causing the sensor's output signal to be zero again.
The whole process output signal of the sensor to the human activity information is shown in Figure 3. It is not difficult to see from the sensor output diagram that the signal output by the sensor for an action of human activity is a complete waveform. In the experiment. If the amplifier is used to amplify the signal, then an oscilloscope is used to observe a positive pulse and a negative pulse. That is, a moving signal sensed by the sensor output approximates a complete l Hz pulse signal.
Third, infrared sensor
1. It has the characteristics of high sensitivity.
2. The two unit devices are connected in reverse. Therefore, the infrared rays input at the same time cancel each other out and there is no output. This increases the stability of external stray light, ambient temperature changes, and external shocks (see Figure 5).
Since the input impedance of the pyroelectric infrared sensor is extremely high, it is very easy to introduce noise.
Therefore, the sensor needs to be electromagnetically shielded, so the metal package is used, and the case is grounded (Fig. 4, Fig. 3, pin 3). This can achieve the purpose of shielding clutter noise.
In nature, the thermal energy radiated by all objects is proportional to its own temperature. The higher the temperature of the object, the shorter the peak wavelength of the radiant heat energy. The temperature of the heat radiated from the human body at a temperature of 36 to 37 ° C is about 900 to 1000 nm, so that the presence or absence of the human body can be detected by a pyroelectric infrared sensor.
In order to avoid the influence of light such as sunlight and illumination during the monitoring of the presence or absence of the human body, a filter is usually attached to the surface of the pyroelectric infrared sensor, and since the movement of the human body is relatively slow, it is also required to carry High-efficiency, Fresnel lenses and other accessories that can be focused on can meet the actual needs of use.