How Do You Choose the Right Battery Pack for Your Industrial Robot?

Choosing the wrong battery for your robotic application leads to poor performance, excessive downtime, and even safety issues. This means missed project deadlines and a product that fails to meet client expectations.

The best battery pack depends on your robot’s specific job. Generally, lithium-ion (Li-ion) and lithium-polymer (LiPo) packs offer the best power-to-weight ratio. The final choice depends on your priority for energy density, physical shape, or discharge rate.

I remember working with an engineering director on a new autonomous warehouse robot. His prototype was underperforming because the battery couldn’t deliver sustained power. By designing a custom Li-ion pack, we doubled its runtime and load capacity. Let’s look at the details we discussed.

What is the best battery for robots?

There is no single "best" battery. The ideal solution is always a balance of power, weight, size, and cost, perfectly tailored to your robot’s function.

For most industrial and commercial robots, Lithium-ion (Li-ion) batteries are the best choice, especially those using LiFePO4 or NMC chemistries. They provide high energy density and a long cycle life, and they are extremely safe when managed by a quality BMS.

Matching Chemistry to the Application

The term "Lithium-ion" covers several chemistries, each with unique strengths. As engineers, we choose the right cell chemistry to match the robot’s primary function, whether it’s long-range patrolling or heavy lifting.

Here is a table we use to help our clients make this decision.

The Critical Role of the BMS

For a complex application like a robot, the Battery Management System (BMS)³ is as important as the battery cells themselves. The BMS is the brain that ensures safety and reliability. A cheap battery pack with a poor BMS is a huge risk in an industrial setting.

A professional BMS for a robot must perform several key functions:

• Cell Balancing⁴: Ensures all cells in the pack charge and discharge equally, maximizing lifespan.
• Thermal Management⁵: Monitors temperature and can prevent operation in unsafe conditions (too hot or too cold).
• Protection Circuits: Guards against over-charge, over-discharge, and short circuits.
• State-of-Charge (SoC) Communication⁶: It must accurately report the battery level back to the robot’s main computer via communication protocols like CAN bus or SMBus.

What is the best power source for robots?

While we specialize in batteries for mobile robots, it’s important to understand the full range of power sources available.

For any robot that needs to move freely, rechargeable battery packs⁷ are the best power source. For stationary robots, like a robotic arm on an assembly line, a direct wired connection to the grid is the most simple and reliable option.

Mobile vs. Stationary Power Needs

The choice is defined by the robot’s workspace.

• Stationary Robots: These are robotic arms bolted to the floor in a factory. They perform repetitive tasks in one location. Mobility is not a requirement, so a direct, tethered AC power connection is the most logical choice. It provides unlimited runtime and consistent power.
• Mobile Robots: These are AMRs in a warehouse, last-mile delivery bots, or agricultural robots. Their primary function is to move through an environment. For these, a custom-designed battery pack is the only viable solution. The engineering challenge is to maximize runtime while minimizing weight and charge time.

What is the 80/20 rule for lithium batteries?

You may have heard about charging strategies to make your batteries last longer. The "80/20 rule⁸" is one of the most effective and widely used methods.

The 80/20 rule is a charging practice designed to maximize the cycle life of a lithium-ion battery. The guideline is to keep the battery’s state of charge between 20% and 80% as much as possible.

The Science Behind the 80/20 Rule

Lithium-ion cells experience the most chemical stress when they are at the extremes of their charge state (below 20% or above 80%). Pushing a battery to 100% or draining it to 0% causes slight, irreversible degradation of the internal components.

By keeping the battery in the middle 20% to 80% range, you drastically reduce this stress. This small change in habit can have a huge impact on the battery’s total lifespan, often doubling or tripling the number of useful charge cycles.

Practical Application in Robotics

In a professional robotics deployment, this isn’t just a suggestion; it’s a programmed strategy. For a fleet of warehouse robots, the autonomous charging docks are often configured to stop charging the robots once they reach 80%. The fleet management software will send a robot to recharge when it hits 20%.

This trade-off—sacrificing a bit of runtime on each trip for a 3x longer battery life—is a huge financial win for any large-scale operation.

Which is better LiPo or Li-ion battery pack?

This can be confusing because LiPo is technically a type of Li-ion battery. The real difference is in their construction and performance characteristics.

Neither is better overall, they are just better for different jobs. LiPo packs use a flexible pouch, making them lightweight with high discharge rates, which is great for racing drones. Cylindrical Li-ion cells are more durable and have higher energy density, making them far better for industrial robots.

Head-to-Head Comparison

For an engineer designing an industrial product, the choice is clear once you compare the technical specifications. Pouch cells (LiPo) are too fragile for a demanding environment where reliability is key. Cylindrical cells (Li-ion) like the 18650 or 21700 are protected by a steel case, making them robust.

Here is a direct comparison for a robotics application.

Conclusion

Choosing the right battery for your robot means matching the battery chemistry and pack design to the specific task. For durable, reliable, and long-lasting industrial applications, a custom-designed Li-ion pack with a sophisticated BMS is the professional choice.