18650 Lithium Battery Repair Guide: Save Old Batteries And Give Them A New Lease of Life

18650 lithium battery repair guide: save old batteries and give them a new lease of life

18650 lithium batteries are widely used in various electronic devices and energy storage systems due to their high energy density and long cycle life. However, as the use time increases, lithium batteries may have problems such as decreased capacity and increased internal resistance, resulting in performance degradation or even unusability. Faced with these "aging" batteries, do we have no choice but to discard them? In fact, through some simple repair methods, we can give some old batteries a new lease of life and extend their service life. This article will provide you with a detailed 18650 lithium battery repair guide to help you save old batteries and reduce resource waste.

1. Reasons for "aging" of lithium batteries

Before trying to repair 18650 lithium batteries, we need to understand the main reasons for their performance degradation:

Capacity decay: During the charge and discharge cycle of lithium batteries, the positive and negative electrode materials will gradually undergo irreversible chemical reactions, resulting in a decrease in active substances and a decrease in capacity.

Increased internal resistance: Factors such as the decomposition of the electrolyte inside the battery and the aging of the electrode materials will cause the internal resistance to increase, affecting the battery's discharge capacity and efficiency.

Electrode passivation: If the battery is not used for a long time or is not fully charged, a passivation layer may form on the electrode surface, hindering the insertion and extraction of lithium ions.

Overcharge and over-discharge: Overcharge or over-discharge will accelerate the damage of the internal materials of the battery, resulting in a decrease in capacity and an increase in internal resistance.

2. Repairable battery types

Not all 18650 lithium batteries with degraded performance can be repaired. You can try to repair them in the following situations:

Performance degradation due to long-term non-use: The battery has a capacity decrease or cannot be charged due to long-term storage.

Slight over-discharge causes low voltage: The battery voltage is lower than the normal range (such as lower than 2.5V) due to over-discharge, but it is not completely damaged.

Electrode passivation causes performance degradation: The battery is not used for a long time or is not fully charged, resulting in a passivation layer on the electrode surface.

3. 18650 lithium battery repair method

For different battery problems, you can try the following repair methods:

Small current charging method:

Applicable situations: The battery voltage is too low due to over-discharge or cannot be charged due to long-term non-use.

How to operate: Use a low-current charger (such as 0.1C) to slowly charge the battery until the voltage returns to the normal range (above 3.0V). If the battery voltage is too low, multiple attempts may be required.

Deep charge and discharge cycle method:

Applicable situations: The battery capacity decreases due to electrode passivation or slight aging.

How to operate: After fully charging the battery, use a small current to discharge to the cut-off voltage (such as 2.5V), and then fully charge it again. Repeat this process 2-3 times to activate the active substances inside the battery.

Low-temperature freezing method:

Applicable situations: The battery performance decreases due to internal crystallization or uneven distribution of electrolyte.

How to operate: Seal the battery with a plastic bag and put it in the freezer of the refrigerator (about -18℃) for 12-24 hours, then take it out and thaw it naturally at room temperature. This method should be used with caution and only as a last try.

IV. Precautions during the repair process

When trying to repair 18650 lithium batteries, you need to pay attention to the following:

Safety first: Avoid short circuit, overcharge, over discharge and other operations during the repair process to prevent the battery from heating, leakage or even fire and explosion.

Use appropriate tools: Use professional chargers and discharge equipment, and avoid using inferior or substandard tools.

Monitor battery status: The voltage, current and temperature of the battery should be closely monitored during the repair process. If any abnormality is found, the operation should be stopped immediately.

Do not over-repair: If the battery performance has not improved after multiple attempts, it means that the battery may be seriously damaged and should not be repaired.

V. Recommendations for the use of repaired batteries

For repaired 18650 lithium batteries, it is recommended to follow the following usage recommendations:

Gradually resume use: When using a repaired battery for the first time, it is recommended to start with low current charging and discharging, and gradually restore to normal use.

Avoid overcharging and over-discharging: Repaired batteries may be more fragile than new batteries, and overcharging, over-discharging and high temperature environments should be avoided.

Regular inspection: Regularly check the voltage, capacity and internal resistance of the repaired battery to ensure its stable performance.

VI. Conclusion

The repair of 18650 lithium batteries is not a panacea, but for some batteries whose performance has declined due to long-term disuse or slight aging, we can extend their service life and reduce resource waste through scientific repair methods. I hope that the repair guide provided in this article can help you better understand and apply 18650 lithium battery repair technology and give your old batteries a new lease of life. At the same time, we should also realize that the daily use and maintenance of batteries are equally important. Only scientific use can maximize the battery life.