When developing a battery pack, two major subsystems must work together efficiently: the battery management system and the stack of cells. Most of the development time is spent determining what type of protection and electrical requirements will be required for the battery pack.
Based on this information, a certain type of cell will be selected for the battery pack. Then the appropriate fuel gauge and charging ICs will be selected for the battery management system. Once these are decided, creating the rest of the battery pack is often simple.
After creating a battery pack, there is one important step that is often overlooked and even forgotten. The step being battery maintenance.
Battery packs are stored on a discharge/charge rack.
Why Routine Maintenance is Critical
Routine battery maintenance is a process that is almost mandatory for rechargeable battery packs after a fixed amount of time. To find this time, we must refer to the cell’s datasheet, which was selected during the development phase.
Often, you will find a “Charge Retention” specification. This will give you the approximate days that the batteries will hold a charge. However, you should look for an additional note, which is often found towards the end of the data sheet.
Key Parameters for Battery Storage
This additional note will often refer to 3 parameters. The first being a certain State of Charge (charge capacity) that the batteries should be stored at. The second is a safe temperature range to store the battery packs. Lastly, a recommended monthly interval to recharge and discharge the battery packs.
With many of the battery packs that we work on at Epec, we tend to find 60% is the recommended capacity for the batteries to be stored at. (Always refer to the datasheet for the manufacturer’s recommended capacity)
SMART battery packs require routine maintenance.
The Risks of Skipping Maintenance
Even if performing battery maintenance might seem tedious and there could be extra labor that must be done, it is necessary. If battery maintenance is not performed during the recommended battery storage timeline, the battery packs will reach an Open Circuit Voltage (OCV).
When this voltage is reached, the cell’s internal protection will activate and cut out any output from the cell. The only way to recover this cell is to charge it. When a cell is stored in its Open Circuit Voltage, it results in poor performance and charge capacity. In worst-case scenarios, this can result in damage to components or complete cell failure. This will make the battery pack unreliable for holding a stable charge. This will result in needing to replace the damaged battery pack with a new battery pack.
Designing a Maintenance Plan
Part of the design process for a rechargeable battery pack should be dedicated to making a process and plan for routine maintenance of the battery pack. This should include a charging and discharging step that follows the battery cell manufacturer’s recommendation. If needed, it may be wiser to have an external company properly store and perform routine battery maintenance for your battery packs. Failing to perform routine maintenance on battery packs leads to a large loss in both money and time.
Summary
With routine battery maintenance being a process that is made to prevent battery pack failures, there should be no reason not to complete it. Customers will question both the reliability and safety of a product if a process such as routine battery maintenance is not performed regularly.
Performing routine battery maintenance saves both money and time. As well as adding to the reliability and quality of your product. This is why routine maintenance matters for your battery packs.
Key Takeaways
- Routine maintenance extends pack life: Regular charging and discharging at recommended intervals prevents premature failures and capacity loss.
- Datasheets provide critical guidance: Manufacturer specifications outline the ideal state of charge, storage temperature, and maintenance frequency.
- Neglecting maintenance has risks: Allowing packs to reach open circuit voltage can trigger protection circuits, reduce performance, or cause irreversible cell failure.
- Plan maintenance early in design: Building maintenance steps into the product lifecycle ensures consistency and reliability across all units.
- Reliability builds customer trust: Properly maintained battery packs deliver stable performance, reduce costly replacements, and safeguard your product’s reputation.
