Can Lithium-Ion Battery be Mixed in One Device?

Dec 16, 2023 | XTAR

People generally assume that all batteries are interchangeable. Often, without much thought, we toss both new and well-used batteries into drawers or containers, rarely considering the need for timely recharging. It’s only when our devices run out of power that we hastily rummage through these drawers, grabbing any available battery for a quick replacement. However, these seemingly innocuous habits can pose unexpected challenges, especially when dealing with lithium-ion batteries.

In this article, we delve into a critical question that often goes unasked: Can lithium-ion batteries be mixed within a single device? This query is more than just technical – it’s about understanding the potential risks and nuances of battery use that are usually ignored in daily life. By shedding light on this topic, we aim to empower you with knowledge that can prevent damage to your devices and ensure your safety. Let’s answer the questions that people often asked and unravel the complexities hidden in these ubiquitous power sources.

Can I mix rechargeable and regular batteries?

Mixing rechargeable lithium-ion batteries with regular alkaline batteries is not recommended. Rechargeable and non-rechargeable batteries differ in voltage and discharge rates, leading to uneven performance and potential damage to your device. For optimal performance, stick to one type – preferably lithium-ion for their rechargeability and efficiency.

Can I mix old and new batteries?

Mixing old and new batteries is generally a bad idea, even if they are the same type and model. As batteries age, they can experience a decrease in their overall capacity and power output, and an increase in their internal resistance. As a result, during usage, the order battery may reach its limit and discharge more quickly than the newer one. This would cause uneven discharge and potentially harming the device or the batteries themselves. It’s best to use batteries of similar age and usage history.

Can I mix different capacities of batteries?

Mixing batteries with different capacities, such as an 18650 2600mAh and an 18650 3500mAh cell, is generally not recommended. Batteries with different capacities will discharge at different rates. The battery with the lower capacity will deplete faster, potentially leading to over-discharge and reducing the overall efficiency of your device.

Can I mix different brands of batteries?

While it’s technically possible to mix different brands, it’s not advisable. Different brands may have varying quality standards and performance characteristics, which can affect the device’s functionality. Lower-quality batteries have a shorter lifespan, overrated capacity and are less stable than higher-quality ones.

Can I mix different types of batteries?

Mixing different types of batteries (like NiMH with lithium-ion) is not recommended. Each battery type has unique voltage levels and charging requirements, and mixing them can cause damage to the batteries and the device.

Usually different types of batteries are various in size, but please note that the AA size is not included. These AA batteries have the same size but in different types, voltages, capacities and discharge rates. They are the rechargeable AA lithium, rechargeable 14500 battery, non-rechargeable CR123A and non-rechargeable AA lithium battery.

If you have a device that requires multiple batteries, it’s advisable to use batteries that are of the same brand, model, and age. This helps ensure that they discharge at a similar rate and maintain a more stable voltage throughout their usage. If you need to replace a battery, it’s best to replace all of them with new batteries from the same batch to ensure compatibility and balance in the battery pack.

How to avoid mix-using batteries?

Understanding why lithium-ion batteries shouldn’t be mixed within a single device is just the first step. Now, let’s bridge theory with practicality. How can we avoid mix-using batteries without causing any inconvenience in our daily life? Here are some practical tips:

Purchase in Sets: Whenever possible, buy batteries in sets or packs. This increases the likelihood that they come from the same production batch and have similar specifications.

Labeling: Label your batteries with information such as purchase date, manufacturer, and capacity. This helps you keep track of different sets and avoid mixing them unintentionally.

Battery Cases: Invest in battery cases or holders designed to keep batteries organized. These cases often have compartments for each battery, reducing the chance of mixing them up.

Rotate Batteries: Implement a rotation system where you use the oldest batteries first. This ensures that all sets of batteries are used regularly, and you can cycle through them without creating imbalances.

Check Before Use: Before inserting batteries into a device, check their labels and make sure they have similar specifications. Avoid mixing batteries with different capacities or from different sets.

Recharge Before Use: If batteries have been in storage for a while, check their charge levels before using them. Recharge any batteries that may have discharged over time to ensure optimal performance. Use a smart battery charger with analyzing function would bring you big convenience.

Grouping: If you have multiple sets of batteries, group them according to their specifications. Use batteries with similar capacities and ages together in devices to prevent imbalances.

Dispose of Expired Batteries: Discard batteries that have reached their expiration date. Expired batteries may not perform reliably, and it’s safer to replace them with fresh ones.

Educate Family Members: If multiple people use devices with replaceable batteries in your household, make sure everyone is aware of the importance of using batteries from the same set and following proper storage practices.



It is okay to temporarily mix batteries in an emergency, but it is not recommended to make this a habit. Quickly go check if there are any mixed batteries in the devices at your home!

Despite batteries being small in size, they involve complex chemical reactions and structures. Taking some time to learn more about lithium-ion batteries can be greatly beneficial in your daily life.


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