In terms of the voltage of each unit cell, both nickel-hydrogen and nickel-cadmium are 1.2V, while the lithium battery is indeed 3.6V, and the voltage of the lithium battery is three times that of the other two. And the weight of the same type of battery is almost the same as that of the lithium battery and the nickel-cadmium battery, while the nickel-nickel-hydrogen battery is heavier. It can be seen that each battery has a different weight, but because of the 3.6V high voltage of the lithium battery, the number of single battery combinations can be reduced by one-third at the same output voltage, which reduces the weight and volume of the formed battery.
2. Memory effect
Ni-MH batteries have the same memory effect as Ni-Cd batteries. Therefore, regular discharge management is also necessary. This kind of regular discharge management is handled in a fuzzy state, and even some discharges are carried out under incorrect knowledge (each discharge or discharge after a few times of use varies from company to company). This cumbersome discharge management It is unavoidable when using NiMH batteries. Relative to lithium batteries, because they have no memory effect at all, they are very convenient and simple to use. It does not need to care about the residual voltage at all, it can be charged directly, and the charging time can naturally be shortened.
3. Self-discharge rate
The nickel-cadmium battery is 15-30% (month). Ni-MH batteries are 25 to 35% (months), and lithium batteries are 2 to 5% (months). The self-discharge rate of the above nickel-metal hydride batteries is the largest, while the characteristics of lithium batteries are extremely low compared to the other two types of batteries.
Ni-MH batteries and lithium batteries cannot withstand overcharging. Therefore, the PICK CUT control method of constant current charging of Ni-MH batteries is the best charging method to stop charging when the charging voltage reaches the highest. For lithium batteries, it is best to use constant current and constant voltage charging methods. If you use the Ni-Cd battery charger-DV control method for charging, Ni-MH batteries and lithium batteries are used.