Advantages and disadvantages of lithium battery
【Advantages】: no memory effect, light weight.
【Disadvantages】: the cost is relatively high, the working current is small, and it is not resistant to overcharge (compared with NIMH).
Lithium batteries include primary lithium batteries (non rechargeable) and secondary lithium batteries (rechargeable). Secondary lithium batteries are divided into Li ion lithium-ion batteries and Li polymer lithium polymer batteries.
In general, digital cameras use rechargeable lithium batteries. Compared with NiMH batteries, the total weight is lighter, but the volume power density ratio is higher than 48%.
Because of this, the production and sales of lithium-ion secondary batteries are gradually surpassing that of Ni MH batteries.
This kind of battery has small discharge and no memory effect, and can charge and discharge more than 600 times. In particular, the Li polymer lithium polymer battery developed in recent years is not only smaller, but also not limited by the cylindrical or square appearance of the battery under normal circumstances, and its total weight is lighter.
Lithium batteries are not resistant to overcharge. If they are used carelessly, they may explode. Therefore, it is necessary to build a control IC to avoid overcharge, but the cost is also relatively high. Because the specifications of lithium batteries are not unified, there will be cases where the batteries can not be bought after the models are stopped production. However, many improvements have been made so far.
Advantages and disadvantages of Ni MH battery
【Advantages】:low price, strong versatility, high working current, environmental protection and stability.
【Disadvantages】: large total weight, short battery life.
The design of Ni MH battery originates from Ni Cd battery, but there is great progress in improving the memory effect of Ni Cd battery.
The main change is to replace cadmium with hydrogen storage alloy, so Ni MH battery is a typical representative of material innovation.
The pollution caused by Ni MH batteries is much smaller than that caused by Ni Cd batteries containing cadmium. Therefore, Ni Cd batteries have been gradually replaced by Ni MH batteries.
Except for a few lithium batteries that can be used once (nikonen-el1 and 2cr5), most of them do not have battery alternatives, which is very troublesome for a long time to go abroad or a large number of users. Ni MH batteries do not have such problems. Alkaline batteries can be used in digital cameras that use Ni MH batteries.
In recent years, more and more digital cameras are using Ni MH batteries, and battery manufacturers are optimistic about this market. They have released high-capacity Ni MH rechargeable batteries one after another, which promotes the rapid development of Ni MH battery technology, the capacity is also increasing, the service time is comparable to that of lithium batteries, and the charger is also more and more advanced, and the charging time is greatly shortened.
The difference between Ni MH battery and Li ion battery
1. High power density: the capacity of Ni MH battery is close to that of Ni Cd battery and Li ion battery, which can determine the coordinated product characteristics of Ni MH battery. It should be noted that there are certain differences in power density, that is, the energy that can be stored in the same capacity, and Li ion battery is three times of Ni MH battery.
2. Self discharge rate: self discharge rate usually refers to the amount of electricity that the battery will lose when it is not in use. The self discharge rate of Ni MH battery and Li ion battery is not very high, but the self discharge rate of Ni MH battery exists for a long time.
If the self discharge rate is too high, the service time of the battery will be greatly shortened, and the service life will end early. As a result, about ten years ago, the low self discharge rate of Ni MH battery was an advantage of the promotion of Ni MH battery activities, while the self discharge rate of Li ion battery can be ignored, which is also the green ecological difference of chemical properties caused by the raw materials used between them.
3. In use: generally, lithium batteries can be charged, used and stopped at any time. Cycle life refers to the number of full charge and discharge, and partial charge and discharge can be understood as a fraction of the life. The key to the use of the battery: the battery can be fully charged for 20 minutes - half an hour to reach saturation, but it must be avoided to charge for a long time after full charge.
After the battery is fully charged for a long time, it will cause side effects. As a result, the capacity will be reduced and the internal resistance will be increased. The capacity will be greatly shortened and the battery will be shut down as soon as a call is made. PPC and other charged chip machines, it is best to always use no charge, mainly considering the problem of power display and measurement.
Which is better, Ni MH battery or lithium battery?
Ni MH battery or Li ion battery is better. In fact, it's hard to say. It mainly depends on what products you use. For example, if you choose to use it on mobile phone flat-panel E-bike, I recommend using Li ion battery. Fully considering the long cycle life, but for digital SLR camera, fully considering the current demand of digital SLR camera Very large, and the power consumption is also larger than that of mobile phones. In terms of high working current output, Ni MH batteries are slightly higher.