Mixing Battery Sizes and Chemistries

Why Can’t You Mix Battery Sizes and Chemistries

Mixing battery sizes and chemistries is generally discouraged because it can lead to various safety and performance issues, such as battery leakage and sub-optimal device performance. For best results, it is suggested that you replace all batteries with the same brand, chemistry, voltage, and size when the device performance becomes unsatisfactory. It is best to be consistent because there will be differences in how each brand is made and performs. For example, some batteries are made for specific applications (such as Dakota marine lithium batteries), and this should be borne in mind when purchasing your battery. Only consider incorporating batteries of different brands for your electronics if the brand you are using isn’t available in the necessary size, voltage, etc.

Types of Batteries

It is critical that you refrain from mixing batteries, not only because there are various types of batteries, each with its own chemistry and characteristics, but also because each battery is designed for a specific purpose.

Here are some common types of batteries:

  1. Alkaline Batteries: Alkaline batteries are one of the most common disposable batteries primarily found in households. They are used in various devices, including remote controls, flashlights, and toys. They provide a reliable power source and have a relatively long shelf life. The alkaline electrolyte of potassium hydroxide is used in the Alkaline battery and was a significant step forward compared to the zinc-chloride cells back in the day. They now offer up to five times the capacity. The build of the Alkaline battery is made up of a zinc base Anode material, and the Cathode material usually consists of manganese-based paste. It is an ion-conducting separator soaked in an alkaline electrolyte with a metallic case and positive terminal. A collector pin would be connected to the negative terminal, and a gasket would separate the negative terminal from the case. This often incorporates a vent to release any pressure build-up caused by abuse or malfunction.
  2. Lithium-ion Batteries: Lithium-ion (Li-ion) batteries are rechargeable and are commonly used in portable electronic devices like smartphones, laptops, and digital cameras. They are known for their high energy density, lightweight, and lack of the “memory effect” seen in some other rechargeable batteries. Lithium-ion batteries use the reversible intercalation of Li+ ions into electronically conducting solids to store energy. These batteries have revolutionized the world of portable electronics and are widely regarded as one of the most significant technological advancements in recent history. They have a high specific energy, meaning they can store considerable power relative to their weight. This characteristic is essential for applications where importance is critical, such as in mobile devices and electric vehicles. Li-ion batteries also possess a high energy density, which refers to the amount of energy they can store in a given volume. This property is crucial for compact, space-constrained devices like smartphones and laptops, where maximizing energy storage within a limited space is essential. Li-ion batteries have a longer cycle life than other rechargeable batteries. They can endure a more significant number of charge-discharge cycles before their capacity significantly degrades. This makes them ideal for applications that require frequent recharging, such as smartphones and electric vehicles.
  3. Lead-Acid Batteries: Lead-acid batteries are widely used for applications such as automobile and marine starting batteries; they are also great options for backup power supplies. They are known for their reliability and ability to deliver high currents. Two main types are flooded (wet cell) and sealed (valve-regulated lead-acid, or VRLA) batteries.
  4. Nickel-Cadmium (NiCd) Batteries: Nickel-cadmium batteries are rechargeable and were once commonly used in portable devices. However, they have largely been replaced by nickel-metal-hydride (NiMH) and lithium-ion batteries due to their lower energy density and cadmium’s environmental concerns.
  5. Nickel-Metal-Hydride (NiMH) Batteries: NiMH batteries are rechargeable and have a higher energy density than NiCd batteries. They are commonly used in cordless phones, digital cameras, and some hybrid electric vehicles.
  6. Lithium-Polymer Batteries: Lithium-polymer (LiPo) batteries are a type of lithium-ion battery with a solid or gel-like electrolyte. They are often used in radio-controlled (RC) devices, drones, and some consumer electronics due to their flexibility in shape and size.
  7. Zinc-Carbon and Zinc-Chloride Batteries are non-rechargeable, disposable batteries often found in low-drain devices like remote controls and flashlights. They have a lower energy density compared to alkaline batteries.
  8. Silver-Oxide Batteries: Silver-oxide batteries are commonly used in small electronic devices such as watches, hearing aids, and calculators. They are known for their long-lasting power and stability.
  9. Lithium Iron Phosphate (LiFePO4) Batteries: LiFePO4 batteries are a type of lithium-ion battery known for their safety and long cycle life. They are commonly utilized in applications where safety is critical, such as electric vehicles.
  10. Rechargeable Alkaline Batteries: Rechargeable batteries can replace disposable alkaline batteries. They are designed to be recharged multiple times, reducing waste.
  11. Flow Batteries: Flow batteries are rechargeable batteries that store energy in liquid electrolytes. They are used in large-scale energy storage systems and are being explored for renewable energy applications.
  12. Sodium-Ion Batteries: Sodium-ion batteries are under development as a potential alternative to lithium-ion batteries, particularly for grid energy storage due to the abundance of sodium.

Each battery type has advantages and disadvantages, making them suitable for different applications depending on energy density, cost, weight, and safety considerations.

Shop Dakota Lithium Batteries

Deep cycle Dakota Lithium battery next to an Automotive Lithium car battery

A Dakota Lithium 12V 135Ah battery on the left is a drop in replacement for car batteries but also has 135 Amp Hours of deep cycle capacity. The DL+ 12V 280Ah battery on the right is a marine starter battery.

Mixing Battery Types and Sizes

Here are some of the key reasons why you should avoid mixing battery sizes and chemistries:

  1. Voltage Differences: Batteries of different sizes and chemistries may have different voltage ratings. Mixing batteries with different voltages can lead to uneven power distribution, damaging electronic devices, or, in extreme cases, posing a fire hazard.
  2. Capacity Mismatch: Batteries come in different capacities (measured in ampere-hours or milliampere-hours), and using batteries with significantly various capacities together can result in an imbalanced discharge and overcharging, which can shorten the lifespan of the batteries and potentially lead to damage or overheating.
  3. Discharge Rates: Batteries with different chemistries often have different discharge rates. (Battery discharge rate, also known as discharge current or discharge rate, refers to the rate at which a battery releases its stored electrical energy as usable power. It is typically measured in amperes (A). It is an important parameter to understand when working with batteries in various applications, such as portable electronic devices, electric vehicles, and backup power systems.) Combining batteries with different discharge rates can result in inefficient energy use and, in some cases, overheating or other safety risks.
  4. Chemical Incompatibility: Mixing batteries with different chemistries, such as lithium-ion and alkaline, can result in chemical reactions that produce heat, gases, or other dangerous byproducts. In extreme cases, this can lead to leakage, rupture, or even explosions.
  5. Reduced Performance: Mixing different chemistries or sizes of batteries can lead to unpredictable and inconsistent device performance. Some batteries may drain faster than others, causing devices to shut down unexpectedly.
  6. Safety Hazards: Mixing batteries can pose a safety hazard, primarily in devices not designed to accommodate different battery types. This can lead to electrical problems, fires, or other dangerous situations.
  7. Warranty Voiding: Using mixed batteries in devices that have warranties may void the warranty, as manufacturers generally recommend using specific battery types and sizes to ensure the safety and performance of their products.

Another cautionary note is not to use unsuitable batteries for the application. With so many different battery types, matching the battery to the job is simple. For example, Dakota marine lithium batteries are designed for use in wet environments on boats and watercraft. They are not suitable for land-based electric vehicles even if they have similar capacity and discharge rates to suitable ones.

LiFePO4 vs. Lithium Ion

It’s essential always to follow the manufacturer’s recommendations for the specific device you’re using. If you need to replace a battery, it’s best to use the same type, size, and chemistry the manufacturer recommends to ensure proper and safe operation. If you have concerns about battery safety or compatibility, consult the device’s user manual or contact the manufacturer for guidance.


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