memory effect: Li-ion battery has not the character but Ni-Cd has. The term, is an alleged effect observed in Ni-Cd rechargeable batteries that causes them to hold less charge. It describes one very specific situation in which certain NiCd batteries gradually lose their maximum energy capacity if they are repeatedly recharged after being only partially discharged. The battery appears to "remember" the smaller capacity.

 

Self-discharge rate: Li-ion battery is better than Ni-Cd but no large difference. The former has a rate of approximately 5-10% per month, and latter 10% per month. The term refers to a phenomenon in batteries in which internal chemical reactions reduce the stored charge of the battery without any connection between the electrodes. Self-discharge decreases the shelf-life of batteries and causes them to have less charge than expected when actually put to use.

 

Safety requirements: Li-ion battery is more vulnerable than Ni-cd, which means it need more safety features that will protect the battery from being overheated or overcharged or others,and which are not needed for Ni-Cd battery. Meanwhile the features add to the cost of Li-ion and that¡¯s why it¡¯s so much expensive than Ni-Cd.

 

2--Other terms:

charging time: how long you have to charge the battery after it¡¯s been fully discharged.

work time: how long the device can run continuously after the battery is fully discharged.

price of 1 battery: it vary from defferent voltages, the higher voltage the higher price.