When to Use double lithium ion battery pack？

By Reg Nicoson

If you are looking for more details, kindly visit SUNJ ENERGY.

Basics

Battery packs are designed by connecting multiple cells in series; each cell adds its voltage to the battery’s terminal voltage.  Figure 1 below shows a typical EarthX 13.2V LiFePO4 starter battery cell configuration.

Batteries may consist of a combination of series and parallel connections.  Cells in parallel increased current handling; each cell adds to the ampere-hour (Ah) total of the battery The EarthX ETX680 is an example of a series and parallel configuration.  The ETX680 configuration, 13.2V / 12.4Ah, is shown in Figure 2.

A weaker cell in series connected cells would cause an imbalance. This is especially critical in a series configuration because a battery is only as strong as the weakest cell (analogous to the weak link in the chain).  A weak cell may not fail immediately but may be drained (voltage dropping below a safe level, 2.8V per cell) more quickly than the strong ones when discharging. On charge, the weak cell may fill up before the healthy ones and be over-charged (voltage exceeding 3.9V per cell).  Unlike the weak link in a chain analogy, a weak cell causes stress on the other healthy cells in a battery.  Cells in multi-packs must be matched, especially when exposed to high charge and discharge currents.  Figure 3 below shows an example of a battery with a weak cell.

Battery Management System (BMS) Cell Protection

A BMS continuously monitors each cell’s voltage.  If the voltage of a cell exceeds the others, the BMS circuits will work to reduce that cell’s charge level.  This ensures that the charge level of all the cells remains equal, even with the high discharge (> 100Amps) and charge current (>10Amps).

A cell can be permanently damaged if over-charged (over-voltage) or over-discharged (drained) just one time.  The BMS has circuitry to block charging if the voltage exceeds 15.5 volts (or if any cell’s voltage exceeds 3.9V).  The BMS also disconnects the battery from the load if it is drained to less than 5% remaining charge (an over-discharge condition).  An over-discharged battery typically has a voltage less than 11.5V (< 2.8V per cell).

Multiple Batteries in Series and or Parallel (each battery with its own BMS)

EarthX batteries are approved for use in applications with up to two batteries in parallel, with no additional external electronics.  The restriction to two batteries allows for normal variations in one battery without adversely affecting the other battery.  For applications with more than two batteries in parallel, please contact EarthX tech support.

EarthX batteries are NOT approved for series operation without EarthX’s engineers design approval.  This restriction is due to the fact that impedance, capacity, or self-discharge rates vary between cells and between batteries.  EarthX offers many 26.4 volt batteries.  It is always preferred to use a single 26.4 volt battery versus two 13.2 volt batteries in series, for the single battery can internally monitor each of the 8 cells in series and ensure the charge level of all cells are balanced.

The wire and connectors used to make the series/parallel array of batteries shall be sized for the currents expected.

Do not connect EarthX batteries with other chemistry batteries.

It is important to use the same battery model with equal voltage and capacity (Ah) and never to mix batteries of a different age.

Please contact EarthX for additional information or application support.

Parallel Operation

Like individual cells, you can combine batteries together in parallel to achieve higher energy/power (amp-hours, amps).  Up to two batteries can be put in parallel.  To combine batteries in parallel, connect positive to positive and negative to negative as shown in Figure 4 right.

It is important to use the same battery model with equal voltage and never to mix batteries of a different age.

When connecting two batteries, it is important to make sure the charge levels are similar (voltages are within 0.3 volt) before connection.  If there is a large difference in charge level, high current can flow between the batteries.

In situations where the batteries are automatically connected/disconnected there must be external equipment to limit the current to less than the batteries maximum charge current specification and/or interconnecting wire ampacity specification.

Series Operation

Unlike parallel operation, series operation or series/parallel operation requires thoughtful engineering and maintenance to make the system function properly.  Contact engineering for design approval.  It is important to use the same battery model with equal voltage and capacity (Ah) and never to mix batteries of a different age.  Both batteries in a series configuration must have the EXACT same load, meaning you cannot connect a load to just one battery in the series.  If you charge one battery you must charge the other to an equal charge level.   If you replace one battery, you must replace the other battery.  See the example below for series wiring (Figure 5).

Series / Parallel Operation

Below is the approved series and parallel configuration (Figure 6). The batteries are wired as two separate series battery paths, meaning there is no cross ties between the centers of the two separate paths. Figure 7 shows an incorrect  connection with a cross tie between the centers of the two separate series paths.

Maximum Safe Operating Limits

Based on extensive testing and knowledge of the cells and BMS design, our battery’s nameplate ratings are de-rated when used in parallel and or series configurations.  For example, the normal maximum charging voltage for a single battery is 14.6V, but when two batteries are put in series the combined normal maximum charging voltage is reduced to 28.8V.  When two batteries are put in parallel the continuous discharge amp rating and charge amp rating is typically reduced to 90% of the two batteries’ combined rating.

For more double lithium ion battery packinformation, please contact us. We will provide professional answers.

Our EarthX batteries have the capability of extremely high discharge rates and charge rates.  However, when our batteries are connected in series and or parallel we recommend you don’t exceed the values shown in Table 1 below.  Please contact us for applications using battery models not shown in this document.

Model # in Parallel # in Series Max Continuous Discharge Amps Max Charge Amps Max Charge Volts ETX18 Instead of two ETX18 in parallel use one ETX36 ETX18 or ETX24 Instead of two in series use one ETX400-24 ETX680/ETX680C Instead of two ETX680C in parallel use one ETX ETX680/ETX680C Instead of two ETX680C in series use one ETX680-24-VNT or ETX900-24 ETX900 Instead of two ETX900 in parallel use one ETX ETX900 Instead of two ETX900 in series use one ETX900-24 ETX Instead of two ETX in parallel use one ETX ETX Instead of two ETX in series use two ETX680-24-VNT or ETX900-24 in parallel ETX Instead of two ETX in series use one ETX-24 ETX900-24 2 1 270A 144A 28.8V

Series / Parallel Operation and Fault Indication

Each EarthX battery requires its own remote fault indication LED.  The 12V LED is connected across the battery’s positive terminal and the remote fault indicator wire (pigtail wire out the side of the battery), see Figure 8 below.  Connecting the remote fault indicator to an EFIS is not an option in any series configuration (12V LED light is the only option).

Series / Parallel Operation Charging (maintenance)

With an approved engineering design, when using two 13.2 volt batteries in series, it is most important to keep the two batteries matched.  If charging is needed, both batteries must be charged to an equal level.  If a battery needs to be replaced, both batteries must be replaced.   Both batteries must have matching capacity, and charge level always.

References

Source1 – EarthX Lithium Battery User’s Manual

Photography is an art form that thrives on precision, creativity, and reliability. For photographers, having the right gear is paramount, including choosing the best power source for their equipment. Regarding portable power, double-A lithium batteries are often overlooked but are a smart choice for photographers. They combine durability, efficiency, and convenience, making them an essential part of any photographer’s gear bag.

In this article, we’ll dive into everything you need about double A lithium batteries for camera gear. We’ll cover everything from understanding their advantages to tips for maximizing their lifespan. Whether you’re a seasoned pro or an amateur photographer, choosing the right battery can significantly improve your workflow and reliability.

Part 1. What are double A lithium batteries?

Double A lithium batteries are compact, cylindrical batteries that store energy using lithium-based chemistry. Unlike traditional alkaline AA batteries, lithium batteries are lighter, longer-lasting, and more reliable under extreme conditions. They are often used in portable devices such as cameras, flash units, and high-power gadgets like LED video lights, making them an excellent choice for camera batteries.

Key features of double A lithium batteries:

• High energy density: They store more power than alkaline batteries of the same size.
• Lightweight design: Ideal for photographers who carry gear for long periods.
• Temperature resistance: Perform well in extreme hot or cold weather.
• Long shelf life: They can retain their charge for years without significant power loss.

A Comprehensive Guide to Camera Battery

Part 2. Why are double A lithium batteries ideal for photographers?

Photographers require batteries that can withstand high energy demands and deliver consistent performance. Double A lithium batteries shine in this regard.

• Reliable power for high-drain devices: Cameras, external flashes, and other photography equipment often need high-drain power sources. Lithium batteries provide a steady voltage output, ensuring your gear operates at peak efficiency without sudden drops in power.
• Lightweight and travel-friendly: Photographers often carry their gear across long distances. Double A lithium batteries are lighter than their alkaline counterparts, perfect for reducing overall weight while traveling.
• Performance in extreme environments: Whether you’re shooting in freezing mountain ranges or scorching deserts, lithium batteries maintain their performance. Unlike alkaline batteries that may fail in extreme temperatures, lithium batteries thrive where others fall short.

Part 3. How do lithium batteries compare to alkaline batteries?

When choosing a battery, many photographers wonder: Are lithium batteries better than alkaline batteries? The answer is a resounding yes, especially for professional use. Here’s a comparison of their key differences:

• Energy density: Lithium batteries have a higher energy density, meaning they last longer than alkaline batteries of the same size.
• Weight: Lithium batteries are significantly lighter, which is beneficial for portable camera gear.
• Shelf life: When stored, lithium batteries can last up to 10 years, while alkaline batteries typically last 5–7 years.
• Performance in extreme temperatures: Lithium batteries perform well in hot and cold environments, whereas alkaline batteries struggle in extreme conditions.
• Cost: Lithium batteries are more expensive upfront but are more cost-effective in the long run due to their durability and longer lifespan.

Comparison Table: Lithium vs. Alkaline Batteries

Part 4. How to choose the right double A lithium batteries for your camera gear?

When selecting batteries for your camera gear, it’s essential to consider your specific needs and shooting style.

• Check compatibility with your devices: Not all camera equipment supports lithium batteries. Always check the manufacturer’s guidelines to ensure compatibility.
• Prioritize reputable brands: Invest in batteries from trusted brands like Energizer, Duracell, or Panasonic. These brands are known for their quality and reliability.
• Look for rechargeable options: If you’re a frequent photographer, rechargeable lithium batteries can save you money and reduce waste. They offer the same advantages as disposable lithium batteries but allow multiple charging cycles.

Part 5. Practical use cases for double A lithium batteries in photography

Double A lithium batteries are not just for cameras. Here are some practical use cases where they shine:

• External flashes: Provide consistent power for rapid flash recycling.
• Wireless triggers: Ensure reliable communication between camera and flash.
• LED lights: Deliver long-lasting performance for video shoots.
• Backup power: Serves as an emergency power source during extended shoots.

Part 6. Tips for maximizing the lifespan of your lithium batteries

To get the most out of your double A lithium batteries, follow these simple tips:

• Store them correctly: Keep your batteries in a cool, dry place to prevent heat or moisture damage. Avoid leaving them in direct sunlight or inside a hot car.
• Avoid mixing old and new batteries: Combining old and new batteries can lead to uneven power distribution, damaging your devices or reducing battery efficiency.
• Remove batteries when not in use: If you’re not using your camera gear for an extended period, remove the batteries to prevent leakage or corrosion.
• Use battery cases: Store spare batteries in protective cases to prevent accidental short-circuiting or damage.

Part 7. Are rechargeable double-A lithium batteries worth it?

Rechargeable lithium batteries are an eco-friendly and cost-effective alternative to disposable options. While the upfront cost is higher, they can be recharged hundreds of times, making them ideal for photographers who frequently shoot.

Benefits of rechargeable lithium batteries:

• Reduced waste: Fewer batteries end up in landfills.
• Lower long-term costs: Save money by reducing the need for replacements.
• Consistent performance: Deliver the same power output as disposable lithium batteries.

Part 8. Common myths about double A lithium batteries

Several misconceptions about lithium batteries may deter photographers from using them. Let’s debunk these myths:

If you are looking for more details, kindly visit iot device battery.

• Lithium batteries are unsafe: Modern lithium batteries are designed with advanced safety features to prevent overheating, leaks, or explosions. As long as you use reputable brands, they are entirely safe.
• Lithium batteries are too expensive: While they have a higher upfront cost, their longevity and performance make them a better investment over time.
• Lithium batteries are only for professionals: Amateur photographers can also benefit from the reliability and convenience of lithium batteries, especially for extended trips or high-drain devices.

Part 9. FAQs