Which battery is best? Well, the most accurate answer is there isn't one single battery that reigns supreme in all situations. All the different types of battery chemistry excel in some situations, but offer challenges in others.
So, let's talk about the four main types of batteries, their characteristics, and why you might want to use one type over another.
Alkaline Batteries
Alkaline batteries are certainly the most widely available and least expensive but have many drawbacks. Alkaline batteries are shipped with a power level of about 1.5 volts but begin to decrease in power the instant they are inserted.
As time goes on, the voltage level continues to decrease proportionally to the time left in the field/number of photos taken. This proportional decrease is especially evident when you examine night photos taken by inexpensive infrared cameras. Photos taken early in the life cycle of an alkaline battery are bright and well illuminated. These early photos also represent the maximum flash range potential of the camera. However, with every passing day, each subsequent night photo is less illuminated. The process continues up until the point where night photos are pitch black and/or the camera shuts off due to low voltage. Our #1 customer service inquiry is:
"WHY DOES MY CAMERA TAKE BLACK PHOTOS AT NIGHT?"
99.9% of the time failing alkaline batteries are to blame.
Cold temperatures adversely affect alkaline batteries as well.
Battery life is diminished and alkaline batteries lose up to half their capacity in sub-freezing weather. This is why so many trail camera users discover large periods of time where their camera didn't capture any photographs, but then find it mysteriously started working again once the temperature rose.
Alkaline batteries are also prone to leaking acid which has claimed the life of many a device. Additionally, they are good for only 1 use and then find their way to the landfill. Most environmentally conscious people avoid the use of alkaline batteries whenever possible.
One redeeming quality of alkaline batteries is they can operate in higher temperatures with no performance loss. This offers many researchers an inexpensive alternative to rechargeable batteries that suffer reduced capacity in hot climates.
To summarize, alkaline batteries are cheap and available everywhere, but provide inconsistent power and don’t work well in the cold, not to mention they are extremely unreliable. They are the #1 source of "trail camera problems."
If you must use alkaline batteries, we recommend only using Energizer or Duracell. In our experience, most off-brand alkaline batteries have substantially less capacity and are very unreliable.
Lithium Batteries
Lithium batteries offer some very interesting benefits. To start, lithium batteries produce 1.6 volts/cell, or as we like to say “They run hot”. Just as decreasing voltage produces weaker flash characteristics, increased voltage can produce a stronger flash with brighter pictures and increased flash range in some cameras.
Due to their chemical makeup, lithium batteries are not affected by any change in temperature, hot or cold. Their increased capacity gives them a roughly 20% longer run time than the best rechargeable cells and twice the run time of the best alkaline batteries. Additionally, single use lithium cells weigh substantially less than alkaline or NIMH cells. This can be a huge advantage for backpacking into remote areas to manage cameras.
Until recently, we have been huge fans of single-use lithium batteries. Even though they were expensive, they were the most consistent power source we could find. Unfortunately, they have not only doubled in price, but we have also documented an increasing number of bad cells. It is common to find one of our recently deployed cameras with new batteries dead. Further inspection reveals one bad cell has completely shut down the entire power supply after just a few days in the field.
Nickel Metal Hydride (NiMH) Rechargeable Batteries
Pros:
Less expensive in the long run
Longer battery life in winter months
"Eco-friendly"
Cons:
Adversely affected by hot weather
Low voltage output
Fully charged, NiMH batteries produce about 1.4 volts. However, they quickly decrease to a working level of 1.2 volts, which they are consistently able to deliver for the rest of the usage cycle. However, the 1.2 working voltage does present a problem for use in some cameras. Most cameras are designed around a 1.5 volt/cell scenario. It is very common for a camera to use 4 batteries, or essentially a 6-volt system (4 X 1.5volts).
Many of these 6-volt systems constantly monitor the voltage and automatically shut the camera off when the voltage dips to around the 5-volt level. With NiMH batteries providing just 1.2 volts/cell, they produce an aggregate voltage of only 4.8 volts. This makes Nimh batteries incompatible with some trail camera models.
What we've learned about Nimh Batteries over the last decade:
Charging is Critical
We have learned What you use to charge your batteries has now become just as important, if not more important, than how and when you charge your batteries. Most inexpensive chargers (think discount store again) charge batteries with a constant level of charge (200 ma) for a set amount of time (8 hours) regardless of how much capacity is remaining in the battery. This would be fine if all of your batteries were fully drained every time you placed them in the charger, but this isn't reality. Typically, when I run cameras I come back to the office with a box full of batteries and no idea how much capacity is left in each cell. Luckily, we use a smart charger with a microprocessor which individually monitors the charging of each cell based on the cell's remaining capacity. The smart charger brings each cell up to a full charge (independent of the other cells) and then switches it over to a trickle charge for storage until it's pulled from the charger. Conversely, cheap chargers apply the same amount of charge to all cells and often overcharge batteries. Batteries exposed to a greater level of charge overheat and lose a portion of their future capacity - some even fail immediately. If you want to fully enjoy the benefits and efficiencies of Nimh batteries, please use a smart charger.
Put your batteries in use the instant they are removed from the charger
NiMH batteries begin to self-discharge immediately after removal from the charger, even if they aren't being used. Each cell loses about 1/2% of its capacity each day until it is completely drained. In order to maximize battery life, plan trips to your scouting area and charge accordingly. When put into the field immediately, we get 2 - 2 1/2 months of battery life from our NiMH batteries.
Set realistic expectations for your batteries
Manufacturers of rechargeable camera batteries make claims of "Hundreds" if not "Thousands" of possible recharges. I'm sure this is possible when used in a high energy device which requires daily charging. However, based on our experience, we expect somewhere between 3-5 years of field use from our NiMH batteries.
Avoid using NiMH batteries during periods of high heat
We've noticed a sharp decline in battery life when temperatures rise above 90 degrees. In fact, during a stretch of 100 degree days, we noticed batteries which normally lasted 10 weeks only surviving for a week or two. When NiMH batteries suffer, alkaline and lithium batteries perform great. We make a point to switch out our NiMH batteries with lithium batteries during the hottest months of the summer.
Lithium Ion (Li-ion) Rechargeable Batteries
Lithium-ion (Li-ion) rechargeable batteries have become an option for a wide range of electronic devices including trail cameras. They offer several advantages over other battery technologies, but also come with a few drawbacks.
Advantages of AA Rechargeable Lithium-Ion Batteries
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High Energy Density: Li-ion batteries can store a significant amount of energy in a relatively small volume, making them ideal for devices where space and weight are concerns.
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Long Cycle Life: Under optimal conditions, Li-ion batteries can be charged and discharged for hundreds to thousands of cycles before their capacity significantly diminishes.
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Low Self-Discharge: Unlike some other rechargeable batteries, Li-ion batteries lose their charge relatively slowly when not in use.
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No Memory Effect: Li-ion batteries do not require full discharge cycles to maintain their capacity, a problem faced by older nickel-cadmium batteries.
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Consistent Voltage: The native voltage of a Li-ion cell is 3.7 volts. Left unmodified, these cells would not be compatible with devices that use standard AA batteries. However, Amptorrent Li-ion rechargeable AA cells have a microprocessor on the tip of the battery which reduces and regulates the voltage to exactly 1.5 volts throughout the entire lifecycle of the battery.
Disadvantages of Lithium-Ion Batteries
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Hard to calculate remaining capacity: AA rechargeable Li-ion batteries produce exactly 1.5 volts throughout their entire life cycle and then abruptly die. As a result, devices are not able to calculate remaining battery life. Trail camera users must keep track of the number of photos taken and swap out batteries accordingly.
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Cost: Advanced manufacturing processes make rechargeable Li-ion batteries more expensive than some other types of batteries. However, the additional expense is usually recaptured in just 2-3 charges making subsequent use nearly free.
Conclusion Lithium-ion rechargeable batteries require a little more attention, but provide consistent, reliable power. Although expensive at first, the batteries pay for themselves after just a few charges.
Shut off voltage (minimum level of voltage required to power camera)
Another item we test is “Shut Off” voltage. Simply put, a scouting camera’s shut off voltage is the minimum level of volts required to power the camera for normal operation. Anything less and the camera will shut off due to insufficient power. While rarely mentioned, this particular attribute becomes relevant in many ways. To fully understand, we must first explain how batteries perform throughout their lifecycle. The graph below illustrates how the voltage in different types of batteries decreases over their lifecycle.
voltage in different types of batteries decreases over their lifecycle.
You’ll notice alkaline batteries start at 1.6 volts and then immediately begin a gradual decline throughout their life until they are “dead”. However, Lithium & Nimh batteries maintain a steady level of voltage (albeit different levels) throughout most their life and then completely die all at once at the end of their life. When combined with the shut off value of a particular scouting camera, the usage curve of each type of battery becomes important in two (2) key areas:
1. Some game cameras are incompatible with certain types of batteries due to their shut off values (minimum power requirement). Most camera manufacturers design their cameras using a 6 volt camera battery power supply (4 batteries at 1.5 volts each = 6 volts). Many of these same manufacturers also program in a shut off voltage of about 5 volts. It is this 5 volt shut off threshold which creates a problem for anyone wanting to use Nickel metal hydride (Nimh) rechargeable batteries. Nimh cells provide consistent power and aren’t affected by cold temperatures like alkaline batteries which can easily lose up to half of their capacity during sub freezing weather. They are also very economical given they can be used for hundreds of charging cycles. However, Nimh batteries have a working voltage of just 1.2 volts/cell or 4.8 volts aggregate when used in the typical trail camera. Unfortunately, anyone who owns a scouting camera with a shut off value above 4.8 volts can’t benefit from the advantages of Nimh batteries.
2. Some Trail Cameras are incapable of utilizing the full mah capacity each battery offers. Using the graph above from the previous example, you’ll notice the voltage in alkaline batteries dips to about 1.2 volts one fifth of the way through its usage cycle. At this point the aggregate voltage in many game cameras has dropped below the shut off threshold forcing the unit to shut off leaving the camera’s batteries with 80% of their capacity unused. Getting back to our automobile gas tank analogy, this would be equivalent to providing a 20 gallon tank with a fuel line which only reached down far enough to access the top 4 gallons. This issue only applies to the use of alkaline batteries. Lithium cells provide adequate voltage throughout their entire life cycle and Nimh batteries shouldn’t be used in any camera with a high shut off voltage.
Right battery
1.5 volts
1.5-volt rechargeable lithium-ion batteries. They're generally marketed and sold in sets of four AA batteries plus a convenient 4-cell charger, all for usually about $ 25.00 - $ 30.00, with free shipping.
Note: While all AA batteries will take decent daytime images and daytime videos, the nighttime camera performance will suffer, or not work at all when using AA batteries that have a voltage less than 1.5 volts.
There's no battery state of charge indicator on the KJK trail camera. So mark on your calendar and replace/recharge batteries every 3 months or whatever the general lifespan of your charged batteries are.