Rechargeable batteries are essential in underwater photography. Your camera, strobes, focus lights, and dive lights all rely on them. These batteries come in both proprietary and standard formats. Proprietary batteries are designed specifically for certain cameras or strobes. However, the most commonly used are rechargeable AA batteries, which are found in a wide variety of devices. This review focuses on these standard AA rechargeable batteries due to their wide applicability and availability.
Battery Selection for Testing
For this review, 20 different types of rechargeable AA batteries from 13 manufacturers were tested. These included various chemistries and performance profiles. A specific category worth noting is the 1.6 V nominal operating voltage batteries with a 2500 mWh capacity. Each battery was evaluated for performance under several controlled conditions to determine real-world usability, especially in high-demand environments such as underwater photography sessions involving strobes.
Battery Testing Tools and Setup
To ensure accuracy and consistency, the batteries were tested using a computer-controlled system. This system connected to a PC via USB and allowed precise software-based control over test conditions. A custom battery holder was built using 12-gauge wire and metal contacts to minimize contact resistance and voltage drop. The system was calibrated with an Agilent E3610A constant current power supply and verified for accuracy within ±3% at 1V and 1A and ±2.5% at 1V and 3A.
Multiple test modes were available, but the primary methods used were constant current mode and pulse mode. Except for the very low current test, four samples of each battery type were tested, and the results were averaged. For on-the-go testing, such as on dive boats, the ZTS Pulse Load Tester is recommended due to its practicality and reliability. Controlled charging was also essential for this test. All batteries were charged using the La Crosse charger, and each was run through a full refresh cycle to ensure consistency before testing.
Low Current Capacity Testing
The first phase of testing was a low current check set at 0.05 amps to validate the manufacturer's labeled battery capacities. This low current test is a theoretical benchmark because many real-world applications demand higher current draws. Since this test takes approximately 50 hours to complete for a battery labeled at 2700 mAh, only one sample from each battery type was used for this segment.
During testing, fully charged batteries typically began at about 1.44 volts. Voltage dropped rapidly to around 1.2 volts, the nominal operating voltage for NiMH cells. As discharge continued, the voltage dropped gradually and then more rapidly as it neared the 0.9-volt cutoff, chosen to simulate the threshold at which many devices indicate a low battery.
The graphical data from this test demonstrated that all batteries performed very close to their labeled capacities when operating at low currents. This outcome confirms that under minimal stress, most rechargeable AA batteries live up to their advertised specifications. However, the low current draw test is not indicative of performance in high-demand environments.
Implications of Low Current Testing
While these low current tests verify labeled performance, actual usage scenarios often require higher current draws. Devices like video monitors may operate efficiently with a few hundred milliamps, allowing batteries to last longer. In contrast, strobes and focus lights draw significantly more power. Therefore, additional testing was conducted to determine how batteries behave under real-world demands where the current draw is far more intense.
Evaluating Battery Performance at 1A Constant Current
To simulate real-world usage more accurately, a second round of tests was conducted with a current draw of 1 amp. This level of current is more representative of the power demand from underwater strobes, focus lights, and other high-consumption equipment. For context, a current measurement was taken from a FIX 500 LED light, and the 1A setting was chosen based on that observation.
At this increased current, the variation in battery performance became much more apparent. Unlike the low-current test, where nearly all batteries met their rated capacity, the high-current test highlighted clear distinctions among battery types. In this test, batteries were grouped into categories based on their internal discharge characteristics.
Comparing Low and Normal Internal Discharge Batteries
The results from the 1A test demonstrated a significant difference between low internal discharge batteries and standard ones. Low internal discharge batteries, identified in red on the data graph, maintained better capacity and voltage over time. In contrast, standard NiMH batteries, shown in blue, experienced a quicker drop in voltage and capacity under the same conditions.
A third category, NiZn batteries, displayed somewhat intermediate behavior. These batteries, marked in green in the graphical data, performed better than standard NiMH but not as consistently as the low internal discharge types.
The Delkin 2900 mAh batteries, for instance, slightly outperformed even the best low-discharge batteries during the 1A test. This makes them a compelling option for users with moderate current demands who want extended run times without transitioning to low internal discharge models.
High Current Testing at 3A
Given the intense power requirements of many underwater devices, a further test was carried out at 3 amps. This level reflects conditions such as a dive light system using four AA batteries to provide an hour of continuous illumination. Testing at this current level provides insight into battery performance when operating under significant electrical stress.
At 3A, the disparity between low-discharge and standard-discharge batteries widened even further. The regular NiMH batteries saw dramatic drops in usable capacity, confirming their inefficiency in high-drain scenarios. Meanwhile, the low internal discharge batteries held up considerably better, offering more consistent voltage and longer operation times.
The NiZn batteries, which had shown promise in the 1A test, also displayed mixed results in this 3A test. They generally performed better than standard NiMH but did not match the stability or longevity of the top low-discharge models. As current demands increased, the differences between battery types became even more critical to consider.
Real-World Application for Underwater Strobes
One of the most important applications of AA rechargeable batteries in underwater photography is powering strobes. Unlike lights with continuous draw, strobes operate by releasing energy in rapid bursts. They charge up, wait, and then fire in short, intense pulses of light. The moment the strobe fires, it enters a high-draw charging phase, which is one of the most demanding times for the battery.
To evaluate how batteries respond to this burst-and-recharge pattern, a pulse testing protocol was developed. The test involved drawing 4 amps of current for five seconds, followed by a fifteen-second rest. This cycle was repeated until the battery’s voltage dropped to 0.9 volts. This simulates the behavior of strobes during a photography session, where periods of inactivity are punctuated by short bursts of high energy usage.
Observations from the Pulse Test
The results from this pulse test provided valuable insight into how well different battery types could manage quick, intense power demands followed by rest periods. A typical run revealed a clear pattern of hysteresis: once current was removed, the voltage would temporarily rise before falling again during the next load cycle. This effect illustrates how batteries momentarily recover when not under load, only to decline again once stress is reapplied.
The data showed that low internal discharge batteries were significantly more capable in this setting. Their consistent voltage levels and slower capacity loss made them the ideal choice for strobe usage. In contrast, standard discharge batteries quickly lost voltage stability, reducing the number of usable flashes and increasing the time required for strobes to recycle and recharge.
Visualizing Battery Differences in Pulse Tests
Graphical data from the pulse tests made it clear which batteries were suited for this demanding task. The low-discharge batteries demonstrated slower declines in capacity and higher retention of usable voltage during repeated bursts. These characteristics translate directly into real-world advantages, such as faster strobe recycling times, more consistent firing, and fewer interruptions during a dive.
Standard NiMH batteries, though often cheaper, showed steep declines in performance with each cycle. This means users might miss crucial photographic moments due to slower strobe readiness or complete power loss before the dive is complete. NiZn batteries again landed in the middle, better than standard types but not quite matching the reliability of top low-discharge options.
Practical Considerations for Strobe Photography
Strobe use is one of the most power-demanding activities in underwater photography. When a strobe fires, it momentarily demands a very high current to charge a flash capacitor. Once the strobe fires, it needs to recharge quickly to be ready for the next shot. This recharge period is where battery performance becomes most visible to photographers. A poor-quality or low-capacity battery will result in longer recycle times, missed shots, and even system errors. Underwater, where visibility windows and subject proximity are often fleeting, even small delays can be costly.
For this reason, choosing batteries that can consistently deliver power in high-drain, pulsed cycles is critical. The pulse test that applied 4A for 5 seconds with a 15-second rest cycle closely mimics real-world strobe use. From that simulation, conclusions can be drawn not just about how long batteries last, but also how reliably they maintain voltage under stress. Photographers working in dynamic, fast-paced underwater environments must rely on batteries that don’t just last long but also recover quickly and stay stable under fluctuating loads.
Understanding Battery Chemistry and Behavior
The behavior of different battery chemistries—such as NiMH, NiZn, and Li-ion—varies greatly under load. Most AA rechargeable batteries used in underwater photography are NiMH because they are widely available, relatively inexpensive, and compatible with most equipment. However, within the category of NiMH, there are significant differences between standard and low self-discharge (LSD) models.
Low self-discharge batteries have an internal construction that allows them to retain charge over extended periods without significant degradation. These batteries also exhibit slower voltage drops under high current draw, which is precisely what makes them ideal for strobes and other power-intensive devices. Traditional NiMH batteries may have slightly higher peak capacities but tend to suffer faster voltage decline and higher self-discharge rates. The pulse testing revealed that LSD batteries consistently outperform standard types in strobe-specific scenarios.
NiZn batteries, while offering higher initial voltages (typically 1.6V per cell), also introduce complications. Not all devices are designed to operate with the higher voltages, and over time, these batteries tend to degrade faster under repeated charge-discharge cycles. Their performance sits somewhere between standard NiMH and LSD NiMH. While they may be suitable for certain strobes, caution is advised because not all devices are voltage-tolerant. Furthermore, their recharge cycles and chemistry differ, requiring specific chargers and additional monitoring.
Performance Metrics Beyond Capacity
While capacity (measured in mAh or mWh) is a useful metric, it doesn’t tell the full story. For photographers using strobes, three other critical performance metrics must be considered: internal resistance, voltage stability, and heat generation.
Internal resistance determines how much energy is lost as heat during discharge. Batteries with high internal resistance will become warm quickly and lose power more rapidly. They also fail to deliver current consistently during high-drain cycles. In the pulse testing, batteries with lower internal resistance held up much better across repeated firing cycles. Low resistance equals better power delivery, especially when the strobe capacitor needs to charge quickly.
Voltage stability is another crucial factor. Even if two batteries have the same rated capacity, one might experience a steep voltage drop after only a few cycles, making it less usable in practical terms. Inconsistent voltage can cause a strobe to behave unpredictably, skip flashes, or enter protection mode. LSD NiMH batteries showed superior voltage regulation over time.
Lastly, heat management can’t be ignored. Batteries that overheat under stress degrade faster, become dangerous in rare cases, and can shorten the lifespan of electronic devices. LSD batteries tend to remain cooler under load due to their construction, making them safer and more efficient for long-term use in field environments.
Selecting the Right Charger for Optimal Results
A battery’s performance is not determined by chemistry and design alone—how it’s charged is just as important. Using a poor-quality charger can result in incomplete charges, overcharging, or even damage to the cells. To ensure consistent test results, all batteries in this study were conditioned using a high-quality La Crosse charger. The charger allowed for a full refresh cycle, which includes a complete discharge followed by a controlled recharge. This process helps restore the battery’s capacity and ensures consistent output.
For everyday users, choosing a smart charger is essential. Look for chargers that provide:
-
Individual cell monitoring
-
Discharge and refresh functions
-
Thermal monitoring
-
Charge completion alerts
-
Adjustable current settings
Smart chargers help prolong battery life and ensure that each battery receives the correct charge for its condition. A well-maintained battery, properly charged, will always outperform a poorly maintained one, even if the specifications are identical.
Avoid fast-charging cheap chargers that push high current into all cells simultaneously. They may be convenient but tend to reduce the lifespan of batteries and increase the risk of overcharging or overheating. Investing in a proper charging station is a small cost compared to the loss of reliability during a critical dive.
Long-Term Battery Maintenance and Storage
Rechargeable batteries degrade over time, and how they are stored when not in use plays a major role in their lifespan. For underwater photographers who may only dive occasionally, using batteries that hold charge for long periods is essential. LSD NiMH batteries are specifically designed for this purpose, maintaining most of their charge even after months of storage.
Store batteries in a cool, dry place and avoid leaving them fully discharged. A good practice is to top them off after use and run a full refresh cycle every few months if they remain unused. If a battery becomes warm while charging or shows signs of swelling, it should be replaced immediately. Marking batteries with usage cycles and dates helps track performance and anticipate replacements before problems arise.
When preparing for a dive trip, charge batteries fully the night before and check their voltage with a pulse tester. Carry spares in a battery-safe case, and never mix old batteries with new ones in a multi-battery device, as the weakest cell will drag down performance.
Evaluating Battery Costs and Lifespan
Many users evaluate batteries based on price alone, but this approach can be misleading. A low-cost battery that fails after 50 charge cycles is far less economical than a high-quality battery that delivers 500 consistent charge cycles. When evaluating cost, consider:
-
Capacity retention over time
-
Number of full charge-discharge cycles
-
Replacement frequency
-
Compatibility with your gear
-
Impact on strobe performance and recycle time
Over time, high-performance LSD batteries like those from Eneloop or Ansmann become a better investment. They reduce missed shots, perform more reliably under load, and last significantly longer. This cost-effectiveness is especially apparent for professional photographers or avid divers who rely heavily on their equipment.
Bulk buying cheap batteries may seem attractive at first, but the cost in performance and reliability often negates any initial savings. Choosing known brands with a strong reputation and proven field performance is recommended.
Battery Safety in Underwater Photography Environments
Using batteries underwater introduces unique safety considerations. While the batteries themselves aren’t submerged, they are exposed to extreme conditions—pressure changes, temperature shifts, and moisture. Even small leaks in a housing can cause corrosion or short circuits if moisture reaches battery contacts.
To prevent incidents:
-
Inspect battery compartments and seals regularly
-
Use silica gel packets in strobe compartments to absorb residual moisture.
-
Dry and clean all battery contacts before and after each dive
-
Never use a damaged or leaking battery.s
Strobe units that rely on AA batteries should be checked between dives. If a battery appears wet, swollen, or discolored, remove and discard it immediately. Water intrusion into a battery compartment can ruin not just the battery but the entire unit. Carrying a waterproof battery container on dive trips is a good habit for transporting and storing spares.
Matching Battery Types to Gear
Not all strobes or lights operate the same way, and choosing the right battery for the right device is essential. Some equipment, especially older models, may not tolerate higher voltage batteries like NiZn. Others may require high-drain batteries for rapid strobe recycling.
Refer to the manufacturer’s specifications and user manuals before choosing a battery type. In general:
-
For rapid-fire strobes: Use LSD NiMH with high current handling
-
For long-burn lights: Use high-capacity standard NiMH
-
For backup lights or low-drain devices: Use cheaper high-capacity batteries
-
Avoid mixing chemistries in the same device.
If possible, run a controlled test with your specific gear to measure recycle times, voltage drops, and total flashes per charge. This real-world data will help you fine-tune your battery selection for best performance.
Field Testing and User Experience
The lab tests conducted in this review provide a controlled overview of battery performance, but real-world use cases can differ. Conditions such as ambient temperature, device compatibility, shooting frequency, and charging behavior all influence actual battery behavior.
Professional photographers in field tests consistently report faster recycle times and fewer failures with LSD NiMH batteries. Brands like Eneloop Pro and Ansmann receive high marks for their consistency, especially over multi-day dive trips. Recreational divers using standard batteries often report longer recycle times, missed flash opportunities, and batteries dying unexpectedly.
One effective approach is to create a dive log that includes battery performance. Record the number of shots taken per dive, recycle times, and any battery changes needed. Over time, this data can help you refine your battery strategy, prevent failures, and improve shooting efficiency.
Advanced Pulse Load Testing and Recycle Time Insights
To push the evaluation further and explore real-world shooting scenarios, pulse load testing was expanded with more aggressive firing simulations. In these advanced tests, the batteries were subjected to high-drain pulses at irregular intervals—mimicking scenarios such as rapid shooting bursts during wildlife or fast-action macro photography.
Each battery was pushed to deliver 4 amps in shorter but more frequent cycles, increasing both electrical stress and thermal buildup. The test continued until each cell reached a cut-off voltage of 0.9V. The goal was to determine which batteries could withstand this level of abuse while maintaining both voltage stability and recycle time within usable limits.
The findings reinforced earlier conclusions. Low self-discharge (LSD) NiMH batteries sustained the highest number of consistent, reliable strobe flashes per cycle. Their performance under load was not only stable but also predictably linear, allowing photographers to estimate remaining shot capacity more accurately. Batteries that started strong but rapidly declined were less favorable in these simulations because they offered unreliable performance after the halfway mark.
In the context of rapid-fire shooting, a battery’s ability to recharge a strobe quickly can define the success or failure of an image. Slower recycle times result in missed opportunities, especially when photographing fast-moving marine life or capturing fleeting behavior. In every test, low internal resistance and thermal stability were directly tied to superior performance in this area.
Environmental and Sustainability Considerations
As the use of rechargeable batteries grows, environmental impact and sustainability must be considered. One of the most compelling reasons to switch from disposable to rechargeable batteries is waste reduction. A single LSD NiMH battery can replace hundreds of alkaline batteries over its lifetime, significantly reducing landfill contribution and chemical pollution.
However, not all rechargeable batteries are created equal. Some cheap models degrade quickly and need frequent replacement, negating their environmental benefits. Opting for reputable brands that prioritize long lifespan and chemical safety makes a more meaningful contribution to sustainability.
Proper disposal is also essential. Rechargeable batteries should never be discarded in general trash due to the presence of heavy metals and chemicals. Recycling centers or take-back programs from battery manufacturers are the best options. Dive shops and professional photographers can partner with these programs to implement responsible battery use practices.
Storage practices also affect sustainability. Batteries that are well-maintained last longer and reduce the need for frequent replacements. Users are encouraged to rotate their battery sets, store them properly, and avoid overcharging or overheating to maximize each battery’s life span.
Battery Trends and Technological Developments
Battery technology continues to evolve, and the underwater photography world will benefit from upcoming advancements. New chemistries and improved manufacturing techniques are expected to deliver higher capacity, longer cycle lives, and better thermal control.
One emerging trend is the increase in hybrid battery types that combine characteristics of different chemistries, aiming to balance high capacity, low discharge, and voltage stability. Manufacturers are also introducing batteries with integrated chipsets for temperature and performance monitoring, although these are currently more common in larger battery formats.
As strobe manufacturers begin designing units specifically optimized for LSD batteries, compatibility and performance are likely to improve. The move toward standardized charging solutions and smart battery packs could also streamline how photographers manage power during trips.
Photographers should remain aware of these changes and periodically reevaluate their battery strategy. What worked five years ago may no longer be optimal, especially with improvements in strobe efficiency, battery density, and charging technologies.
Real-World Scenarios: Battery Strategy for Dive Trips
Planning for a dive trip involves not just selecting the right gear, but also managing power logistics. Most photographers bring multiple sets of batteries to cover several dives per day. Ensuring these batteries perform consistently under different environmental conditions is crucial.
For example, in cold water environments, batteries tend to discharge faster. LSD NiMH cells have shown better temperature tolerance compared to standard types, retaining more capacity and operating longer in cold conditions. Photographers planning trips to colder dive sites should test their batteries in advance or choose models with proven low-temperature reliability.
Traveling internationally with batteries also presents logistical challenges. Many airlines limit the quantity and type of batteries allowed in carry-on and checked luggage. Always check airline regulations and carry batteries in their original packaging or fire-safe containers. Use protective caps or cases to prevent terminals from shorting in transit.
On location, manage your charging schedule carefully. Set up a charging station with a surge protector and charge batteries in a safe, dry area away from saltwater exposure. Rotate sets to ensure equal usage and track performance using simple notations or apps.
Troubleshooting Battery and Strobe Issues
Sometimes a strobe may misfire or fail to recycle properly. Before assuming the strobe is malfunctioning, check the batteries. Common symptoms of battery-related issues include:
-
Inconsistent firing
-
Slow or failed recycling
-
Sudden power loss mid-dive
-
Overheating during charging
Using a pulse load tester before dives can help verify battery readiness. If a battery fails to hold voltage under load, replace it immediately. Avoid mixing brands, capacities, or charge levels in a single device, as this can unbalance power delivery and shorten the device’s operational life.
If a particular strobe seems unusually demanding, consider upgrading to a higher-performance battery set or consult the manufacturer for battery recommendations. Certain strobes are known to perform better with specific chemistries or capacities.
Conclusion:
Selecting the best battery for your strobes is about more than just capacity numbers. It requires understanding your specific equipment, shooting style, and environmental conditions. The extensive testing conducted in this review shows that. Ultimately, the right battery choice enhances your ability to capture fast-paced action, minimizes downtime, and contributes to a more sustainable approach to underwater photography. For serious photographers, especially those working in dynamic or extreme environments, battery strategy is as critical as camera settings or lens selection. Understanding how your batteries behave under real-world conditions empowers you to make better decisions, shoot longer, and come home with the images you intended to create. Let your lighting system work as hard as you do. Choose the right batteries, and your strobes will keep up every step of the way.