Calculation of lithium battery life

“The lithium battery" is a kind of battery using lithium metal or lithium alloy as the anode materials, using electrolyte solution and water battery.Lithium battery is put forward as early as 1912 by Gilbert N. Lewis for study.In the 1970 s, M.S.W hittingham began to study lithium ion batteries.Due to the lithium chemistry is very lively, it makes lithium metal processing, storage, use have very high demand on the environment.So lithium battery has not been applied for a long time.With the development of science and technology, the lithium battery has now become the mainstream.

Lithium battery can be roughly divided into two categories: lithium battery and lithium ion batteries.Lithium ion battery does not contain lithium metal state, and can be recharged.The fifth generation of rechargeable battery product lithium battery was born in 1996, its security, specific capacity, self-discharge rate and cost performance is better than that of lithium ion batteries.Because of its high technical requirements limit, now only a few countries in the production of this kind of lithium battery.

Battery life

Lithium ion battery can charge and discharge 500 times?

Believe that the vast majority of consumers have heard of, the life of the lithium battery is "500", 500 times more than the number of times, the battery will "die", many friends in order to be able to extend battery life, each time to charge when the battery run out completely, so really have a longer effect on battery life?The answer is no.Lithium battery life is "500", refers not to the number of charge, but a charge and discharge cycles.

A charge cycle means that all the power battery by full use empty, again by the empty into the full process, this is not the same as to charge., for example, a piece of lithium electricity on the first day only half of the battery, then charge for it.If so, the next day with half of the charge, the total charges down, it can only be counted as a charge cycle, instead of two.Often, therefore, may be charging after several times to complete a cycle.Each completed a charge cycle, battery capacity will reduce a little.The power decrease rate is very small, however, the high quality of battery charge cycle for many times, still retains the original capacity of 80%, a lot of lithium electric power products after two or three years later still use as usual.The Li-ion battery life in the final and, of course, is still need to be replaced.

The so-called 500 times, is refers to the vendor in the constant depth of discharge (e.g., 80%), the number of rechargeable 625 times or so, to 500 charge cycles.

Due to the various influence of real life, especially when charging the discharge depth is not constant, so "500 charge cycles" can only be used as a reference battery life.

Theoretically V2000mAH lithium battery power is 3.7 3.7 * 2 = 7.4 WH, at the same time, more than 100 LED lights in the light of power is (white LED is 3 v/a) : 3 * 0.02 * 100 = 6 w, so WH / 6 w = 1.2 7.4 H more, which is 1 hour and 15 minutes, 2 of the same batteries is 2 hours and 30 minutes or so, section 3 is about 3 hours and 45 minutes, but this is the ideal state, in fact even with the most energy saving efficiency highest switching circuit for constant current drive, efficiency is only less than 90%, with the actual estimated within 3 hours, 3 section if use simple analog circuit and current limiting resistor, efficiency will be greatly reduced, estimate what can only be used within 2 hours or less.

Section battery is more than 1 hour, two double their time together, three is 3 times, of course, this is in the ideal state, which is lossless, at least, is to use the most energy saving efficiency of the highest switching circuit for constant current drive, it is to beat the time almost 8 fold. As for the second quarter even you ask what the inside of the circuit with voltage current change, first you need to inform is type switch circuit and analog circuit, switching circuit has said the above, mode depends on the actual circuit, but low efficiency than the former, preferring to second quarter than the long section is certain. You should upload the circuit diagram.

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