How to Choose the Best Battery for Your Next Project

Overview

Battery technology is constantly changing and has come a long way over the last few decades. Depending on your application, a certain chemistry of battery may be better suited: Alkaline, Zinc-Carbon, NiCd, NiMh, Li-Ion, LiFePO4, and SLA each have unique attributes for unique projects. 

Alkaline Batteries

Alkaline batteries are very popular and can be found nearly everywhere. These are typically 1.5v per cell and offer a low self discharge, low cost, and reasonable energy density.  

When to use:

• For small consumer devices like TV remotes; their wide availability allows consumers to easily replace them when needed.  
• If compliance is needed. Alkaline batteries often require less testing or special shipping requirements than other chemistries. For example, NASA used to modify iPods to use alkaline batteries instead of secondary lithium batteries for use on the space shuttle. 

When not to use:

• If low self discharge is needed. These batteries will have a shorter shelf life than some other primary (non-rechargeable) battery chemistries. This characteristic of this battery chemistry wouldn’t be ideal for devices like smoke alarms where primary lithium batteries are the common recommendation. 
• If high energy density is not needed.  Alkaline batteries are heavier and larger than some other chemistries like li-ion, making them less ideal for light applications, such as remote control planes and drones. 

Zinc-Carbon Batteries

Zinc-Carbon batteries are often sold as “heavy duty” batteries. These are typically a lower cost alternative to alkaline batteries. 

When to use:

• If cost is a major driving factor. Carbon zinc batteries are often the “included” batteries with cheaper children’s toys or TV remotes.

When not to use:

• If a high discharge current is required. Applications that require large amounts of power like high-powered flashlights or cordless power tools might not function as designed with this type of battery.
• If a large capacity is needed. Zinc-carbon batteries typically have less energy store in them than alkaline batteries.  For products that need a long run time, this chemistry isn’t the best solution.  

Lithium (Primary) Batteries

Primary lithium batteries are a relatively newer chemistry.  These cells range in size from small watch batteries to much larger cells. 

When to use:

• If the application has low current draw, such as in smoke alarms or watches.
• If low self discharge is needed.
• If the weight of cells is critical. Typically, primary lithium cells are lighter than other primary chemistries.
• If a small battery is needed. Primary lithium batteries come in many small sizes, making them ideal for watches and hearing aides. 

When not to use:

• If low cost is a major requirement. Primary lithium cells typically aren’t the cheapest chemistry.  

NiCd (Nickel–Cadmium) Batteries

NiCd batteries are often lower cost than NiMh batteries or lithium-based batteries. They can have a memory if not charged and cared for properly. 

When to use:

• If a low-cost rechargeable battery is needed.
• If a long lifespace is needed. NiCds typically can be charged and discharged a large amount of times. If done properly, these batteries can be charged more times than other rechargeable chemistries.

When not to use:

• If the conditions of use are not known. NiCd require a specific charging procedure for best longevity. For applications where this procedure might not be kept, other batteries may be best suited.  

NiMh (nickel–metal hydride) Batteries

These batteries often contain more energy, more resilience, and offer a lower number of cycles than NiCd batteries. 

When to use:

• If a high discharge current is needed, such as in cordless power tools.
• If the charging procedure is not known. For example, if the battery may be charged when it is at half capacity, this would be detrimental for NiCd batteries but would be fine for NiMh batteries.  

When not to use:

• If long life span is needed. The advertised life of NiMh batteries are typically fewer than 1000 cycles. If a product is going to be recharged daily, the life of a battery may not last longer than a few years. 

SLA (Sealed Lead) Batteries

SLA batteries are typically larger batteries for use in applications where large amounts of power at a low cost are needed. 

When to use:

• If large amounts of power need to be stored.
• If cost plays a large role in the cost. These cells are often cheaper when compared to other chemistries of the same capacity.

When not to use:

• If weight is a concern. The primary component of this chemistry of battery is lead, so these cells are often very heavy. 
• If many cycles are needed.  Typically these cells are only good for a few hundred cycles. 

Lithium (Secondary) Batteries

This is a broad category that contains many different chemistries. Typically though, these batteries offer the highest energy density. 

When to use:

• If high energy density is needed. These cells typically have higher energy density.
• If high discharge current is needed. Some lithium cells have a discharge current up to 90 times their rated capacity.

When not to use:

• If battery compliance testing will be too costly. Most lithium batteries need to undergo testing before they are allowed to be transported. Additionally, most US shipping carries have other rules and regulations for shipping lithium batteries.

There you go! Now you're armed with all the knowledge you need to get energized!