The difference between laptop Ni-MH battery and Lithium Battery

Now, most of the laptop batteries are Lithium battery, but several years ago, most of the batteries are Ni-MH battery, why is it so, today we will introduce the difference between Ni-MH battery and Lithium battery, tell you why lithium battery will replace Ni-MH battery.

1. Weight

To look at the voltage of each unit cell, Nickel-metal hydride batteries and nickel-cadmium batteries are 1.2V, while the lithium battery is 3.6V, the voltage of the lithium battery is three times than that of the other two. And the same type of battery weight, lithium and nickel-cadmium batteries is almost equal, but nickel metal hydride batteries weight is heavier than that two. We can see, each battery weight is different, but lithium 3.6V high voltage, In the case of  output the same voltage can make each battery combination number reduce one third, and can make  battery  weight and volume decrease after forming.

2. Memory effect

The nickel-metal hydride batteries and nickel-cadmium batteries all have memory effect. Therefore, the regular discharge management is required. This periodic discharge management belongs be processed in a fuzzy state, and even some discharge was under incorrect knowledge (each discharge or discharge after using a few times due to the different companiesand are different). This cumbersome discharge management can not be avoided when using the nickel-metal hydride battery, but Lithium battery memory effect is almost negligible, it is very simple during using, you need not notice how much power the battery has left, it can be charged directly, the charging time is natural can be shortened.

3. Self-discharge rate

Each batteries will discharge itself when you do not use it and put it for long time, but their self-discharge rate is different, Nickel-cadmium batteries is 15~30% per month, Ni-MH battery is 25~35% per month, lithium batteries is 2~5% per month. Thus, the nickel-metal hydride battery self-discharge rate is biggest, but the biggest superiority of lithium battery is its self-discharge rate is very low compare with other two kinds of batteries.(HP Pavilion dv4 Laptop Battery)

4. Charging method

The nickel-metal hydride batteries and lithium batteries can not withstand overcharge, so when the Ni-MH battery’s charging voltage reach highest, stop charging is the best charging method, and the lithium battery use the constant current, constant voltage charging method is best.