Practical Tips to Avoid Overcharging and Deep Discharging

In applications such as electric bicycles, energy storage systems, AGVs, and robots, battery life and safety often depend on two critical yet frequently overlooked factors: overcharging and deep discharging.

As a manufacturer with many years of experience in lithium-ion battery customization and mass production, Level 1 Power has found in practical projects that many battery problems do not stem from the quality of the battery cells themselves, but from improper use and charging/discharging management.

This article will share a set of truly actionable techniques based on engineering practice to help users effectively extend the life of lithium-ion batteries and reduce safety risks.

I. Why Must Overcharging and Deep Discharging Be Avoided?

1. The Dangers of Overcharging

When a lithium-ion battery is kept at full charge for a long time, or continues to be charged after the voltage has reached its upper limit, the following problems can occur:

Increased internal pressure in the battery cells, accelerating material aging

Abnormal temperature rise, increasing the risk of thermal runaway

Significantly shortened battery cycle life

Even with a BMS (Battery Management System), frequent "charging to full capacity" will still cause cumulative damage to the battery cells.

2. The Impact of Deep Discharging

Deep discharging refers to the battery's charge being depleted to a very low level (e.g., below 10%), or even completely discharged:

The battery cell voltage is too low, which may cause irreversible damage

Increased internal resistance, making capacity recovery difficult

Multiple deep discharges will significantly shorten the battery's lifespan

In actual after-sales cases, deep discharging often causes more severe damage to battery life than high-rate discharging.

II. 5 Practical Tips to Avoid Overcharging

1. No Need to Charge to 100% Every Time

In daily use, controlling the charging limit to 80%-90% can significantly extend battery life.

This is especially effective in applications such as commuter electric bicycles, AGVs, and robots.

In some customized projects,  has set charging cutoff strategies through the BMS to help customers achieve a balance between lifespan and range.

2. Disconnect the Power Immediately After Charging

Avoid leaving the charger plugged in for extended periods, especially:

Long-term charging overnight

Continuing to connect to the power source after fully charging in a high-temperature environment

Even if the BMS cuts off the main circuit, continuous trickle charging and high voltage environments will still accelerate aging. 3. Use a Matching Charger

Mismatched charger parameters are one of the common causes of overcharging:

High output voltage

Charging curve does not match the battery chemistry

Lack of temperature or voltage feedback mechanism

Level 1 Power recommends always using the original or verified dedicated charger, especially for customized battery systems.

4. Avoid Charging in High-Temperature Environments

Charging under high-temperature conditions causes more intense internal battery reactions:

More likely to trigger overvoltage and overtemperature protection

Causes long-term damage to the battery cell structure

It is recommended to charge in an environment of 10°C–35°C, which is the ideal range for most lithium batteries.

5. Utilize Smart BMS Functions

Modern BMS is not just a "protection board," but can also achieve:

Precise control of charging cutoff voltage

Cell balancing to prevent localized overcharging

Charging status monitoring and anomaly alarms

In Level 1 Power's customized battery solutions, the BMS is always designed as a core system, not an auxiliary component.

III. 5 Practical Tips to Avoid Deep Discharge

1. Start Charging When the Battery Level is Below 20%

Maintaining the battery level between 20% and 80% is one of the golden rules for extending lithium battery life.

Frequently letting the battery drain until automatic shutdown is not good for the battery.

2. Do Not Store the Battery Fully Charged or Completely Discharged for Extended Periods

If the device needs to be stored for a long time (more than 1 month):

It is recommended to keep the battery level between 40% and 60%

Check the battery status every 2–3 months

This effectively prevents excessive discharge due to self-discharge.

3. Regularly Wake Up Idle Devices

Even if the device is not in use, the BMS and communication modules still consume a small amount of power.

Long-term neglect may cause the battery voltage to drop below the safety threshold.

4. Avoid High-Current Discharge in Low-Temperature Environments

Low temperatures significantly reduce the discharge capacity of lithium batteries:

Voltage is more likely to drop rapidly

May trigger undervoltage protection

In cold environments, it is recommended to reduce the load or preheat the battery.

5. Choose Batteries with Undervoltage Protection and Recovery Mechanisms

High-quality battery systems should have:

Precise undervoltage protection points

Reasonable recovery logic

Design to prevent misjudgment leading to "false death"

This is precisely the direction that Level 1 Power focuses on in its BMS software and hardware design. IV. From the Manufacturer's Perspective: Design is More Important Than Usage

From First Power's perspective, a truly reliable battery system should not be entirely dependent on user habits.

Therefore, in our customized battery projects, we usually control the process from the source:

Setting reasonable charge and discharge voltage windows

Limiting extreme usage scenarios through BMS (Battery Management System)

Selecting high-consistency and aging-resistant battery cells

Designing a lifespan strategy based on application scenarios

These designs can largely "prevent users from making mistakes."

V. Conclusion

Overcharging and deep discharging may seem like minor issues at the usage level, but they directly determine the safety, lifespan, and long-term stability of a lithium battery.

Through scientific usage habits and reliable battery design, batteries can truly deliver their intended value.

First Power consistently adheres to an application-oriented approach, providing lithium battery solutions that are not only "functional" but also "durable, reliable, and suitable for long-term cooperation."

If you are looking for customized lithium battery solutions for electric bicycles, energy storage systems, AGVs, robots, or other equipment, please feel free to contact the First Power team for further discussion.