The best way to extend their cycle life is to keep the batterys charge level between 20% and 90%.

Lithium-ion batteries are not better when fully charged (whether they are Lipo Batteries or Li-ion Batteries). Also, they should not be charged only when they are completely drained. The best way to extend their lifespan is to keep the battery level between 20% and 90%. 

1.Lithium batteries do not have the memory effect. There is no need to deliberately charge them fully.

Previously, nickel-cadmium batteries had the memory effect. They had to be fully charged when the battery was depleted. But nowadays, lithium lipo batteries have no such problem. They can be disconnected even when not fully charged. On the contrary, charging the battery completely each time after it is fully discharged is considered deep charging and discharging. This will damage the structure of the positive and negative electrode materials, causing the battery capacity to decrease more rapidly. 

2. Long-term full-charged state accelerates battery aging

If the battery remains at 100% full charge for a long time, it is equivalent to being in a high-pressure environment for a long period. The internal chemical reactions become more intense, significantly accelerating the rate of capacity loss. It's like a person constantly keeping their nerves tense without relaxation; the "calendar cycle life" of the battery will be shortened, and the degree of deterioration will be much greater than when it is used normally. 

3. Moderate charging and discharging is the scientific way to extend battery life.

Numerous practical tests and studies have shown that maintaining the battery charge between 20% and 90% and charging as needed can effectively reduce the internal chemical stress of the battery. A real-world comparison of electric vehicles has revealed that drivers who keep their battery at a moderate charge level every day have a battery health level that is approximately 4% higher after three years compared to those who wait until their batteries are almost depleted before charging. The battery degradation is also slower. 

4. Avoid repeated minor charging losses after full charge

Although modern mobile phones and electric vehicles have intelligent management systems that automatically cut off power to prevent overcharging, if the device is constantly plugged in and the battery drops by 1% and then immediately recharged, this repeated minor charging will also accumulate small losses. Therefore, deliberately not charging the battery to 100% can reduce the number of "float charges", which is only beneficial for long-term use.