The type and capacity of the battery used in rechargeable emergency lights are pivotal factors that influence their performance and reliability.

Battery Types
Several battery types are used in rechargeable emergency lights, but lithium-ion (Li-ion) batteries are the most prevalent and preferred choice due to their superior performance. Here's a closer look at different battery types and why Li-ion batteries are the industry standard:
Lithium-Ion (Li-ion) Batteries: Li-ion batteries are known for their high energy density, low self-discharge rates, and extended lifespan. These batteries offer the best balance between capacity, energy efficiency, and durability. Li-ion batteries provide a reliable power source, ensuring that the light maintains its brightness over time. They are also lightweight, making them suitable for portable and handheld emergency lights.
Nickel-Metal Hydride (NiMH) Batteries: NiMH batteries are a suitable alternative to Li-ion batteries in some cases. They have good capacity and are rechargeable, but they tend to have a higher self-discharge rate than Li-ion batteries, meaning they may lose their charge more quickly when not in use. NiMH batteries are more commonly found in older rechargeable emergency lights or devices that require a lower capacity battery.
Lithium-Polymer (LiPo) Batteries: LiPo batteries are similar to Li-ion batteries in terms of energy density, but they come in a more flexible and lightweight pouch-style packaging. They are commonly used in applications where shape and size constraints exist. These batteries provide high capacity and excellent energy efficiency but may require specific charging and protection circuits due to their sensitivity to overcharging and over-discharging.
Li-ion batteries remain the top choice for rechargeable emergency lights due to their combination of high capacity, low self-discharge rates, durability, and overall performance. They offer the best balance between power and practicality for a variety of applications.

Battery Capacity (mAh)
The battery capacity is measured in milliampere-hours (mAh) and determines how long your rechargeable emergency light can operate on a single charge. Understanding the relationship between battery capacity and runtime is crucial when selecting the right light for your needs:
Higher Capacity Batteries: Rechargeable lights with higher capacity batteries provide longer runtime. If you anticipate extended power outages or a need for prolonged illumination, a light with a higher mAh rating is essential. These lights can stay operational for several hours or even days, depending on the capacity and energy efficiency of the light.
Lower Capacity Batteries: Lights with lower capacity batteries are still valuable for shorter-term use. They may be suitable for scenarios where you need intermittent lighting for a few hours, such as during brief power outages or outdoor adventures that last a single day.