1. How to Charge a New 48V Lithium ion Battery

When lithium batteries are stored for a period of time, they enter a dormant state, causing their capacity to be lower than normal and their usage time to shorten. However, lithium batteries are easily activated—typically, 3 to 5 normal charge-discharge cycles are sufficient to restore their full capacity. Unlike nickel-based batteries, lithium batteries almost do not suffer from memory effect. Therefore, no special methods or devices are needed to activate new lithium batteries in your mobile devices.

A common myth is that the first three charges of a lithium battery should exceed 12 hours each to activate the battery. This belief, which originated from nickel-based batteries (such as nickel-cadmium and nickel-metal hydride), is incorrect for lithium batteries. Lithium batteries and nickel batteries have very different charge and discharge characteristics. All reliable technical documentation clearly states that overcharging and over-discharging can cause significant damage to lithium batteries, especially liquid lithium-ion batteries. Therefore, it is best to charge according to standard times and methods, avoiding excessive charging periods (e.g., charging for more than 12 hours).

Moreover, lithium batteries and chargers automatically stop charging when the battery is full. There is no "trickle" charging after the battery reaches full capacity, unlike nickel battery chargers. Continuing to charge a lithium battery after it is fully charged will not be beneficial and can potentially be harmful. Thus, it is recommended to avoid long charging durations beyond what is necessary.

Additionally, it is important to avoid over-discharging lithium batteries, as deep discharge can also be detrimental.

2. When to Start Charging During Normal Use

There is a common belief that you should let the battery drain completely before recharging to extend its lifespan. However, the lifespan of lithium batteries is not related to this practice. An example of lithium-ion battery cycle life data is as follows: with 10% Depth of Discharge (DOD), the cycle life exceeds 1000 times; with 100% DOD, it exceeds 200 times. DOD refers to the depth of discharge, and the cycle life is significantly longer with shallower discharges.

In practice, it is better to follow a moderate approach. Charge the battery when it gets low but avoid extreme discharges. For example, if you anticipate needing battery power for the next day and the current charge is insufficient, you should recharge before it runs out. It is not necessary to fully deplete the battery before charging.

The idea of depleting the battery before recharging, which is common advice for nickel batteries, is not necessary for lithium batteries. Over-discharge can lead to very low voltage conditions, which may prevent proper charging or device operation. Therefore, it is advisable to keep lithium-ion batteries from completely draining.

It is recommended to charge lithium batteries to about 80-90% of their full capacity. Avoid charging to 100% all the time or discharging to 0%. Charging within 2-3 hours is ideal, and it is not necessary to charge until full. Every 3-4 months, it is beneficial to fully charge and then fully discharge the battery once or twice.

For long-term storage, lithium batteries should be kept in a cool, dry place with about 70-80% charge. Storing fully charged batteries or completely drained batteries can be harmful. Check and recharge the battery every 3-6 months if not in use.

Lithium-ion batteries can be categorized into liquid and polymer types. Polymer lithium-ion batteries use a gel electrolyte, which is more stable and less prone to leakage, offering better safety.